Patent Publication Number: US-2023140149-A1

Title: Failover of domains

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional application No. 63/273,823, entitled “Failover of Domains”, filed on Oct. 29, 2021, the disclosure of which is incorporated by reference herein in its entirety for all purposes. 
    
    
     BACKGROUND 
     A cloud service provider (CSP) can include multiple data centers that can provide services to users. Each of the data centers can have domains that can be accessed to provide services to the users. However, the data centers may have issues that can cause the data centers to become unavailable to the users. 
     When a data center becomes unavailable when a user is making use of the data center, the user may be dropped and the services provided by the data center may become unavailable to the user. In some approaches, the user may be transferred to another data center that can provide services to the user. However, these legacy approaches of transferring a user to another data center can take a significant amount of time to transfer the user to another data center. 
     SUMMARY 
     An aspect of the present disclosure is directed to a method for failover of a domain, where the method may include providing, by a cloud service provider (CSP), access to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region. The method may further include determining, by the cloud service provider, that the first data center in the first geographic region has become unavailable, and determining, by the cloud service provider, that the second data center in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address. Further, the method may include providing, by the cloud service provider, access to a replica of the domain that resides in the second data center in the second geographic region based at least in part on the determination that the second data center in the second geographic region is to be utilized as the backup data center and the determination that the first data center in the first geographic region has become unavailable. 
     An aspect of the present disclosure is directed to one or more non-transitory computer-readable media having instructions stored thereon, wherein the instructions, when executed by one or more processors, may cause a cloud service provider to provide access to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region. The instructions, when executed by the one or more processors, may further cause the cloud service provider to determine that the first data center located in the first geographic region has become unavailable, and determine that the second data center located in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address. Further, the instructions, when executed by the one or more processors, may cause the cloud service provider to provide access to a replica of the domain that resides in the second data center located in the second geographic region based at least in part on the determination that the second data center located in the second geographic region is to be utilized as the backup data center and the determination that the first data center located in the first geographic region has become unavailable. 
     An aspect of the present disclosure is directed to a cloud service provider that may include one or more data centers located in one or more geographic regions to provide services to one or more user devices, and one or more processors to control access to the one or more data centers located in the one or more geographic regions. The one or more processors may cause access to be provided to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region. The one or more processors may further determine that the first data center located in the first geographic region has become unavailable, and determine that the second data center located in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address. Further, the one or more processors may cause access to be provided to a replica of the domain that resides in the second data center located in the second geographic region based at least in part on the determination that the first data center located in the first geographic region has become unavailable. 
     The foregoing, together with other features and embodiments will become more apparent upon referring to the following specification, claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example cloud service provider (CSP) arrangement, according to at least one embodiment. 
         FIG.  2    illustrates an example mapping arrangement, according to at least one embodiment. 
         FIG.  3    illustrates an example CSP arrangement, according to at least one embodiment. 
         FIG.  4    illustrates an example CSP arrangement with one or more data regions unavailable, according to at least one embodiment. 
         FIG.  5    illustrates an example address update arrangement, according to at least one embodiment. 
         FIG.  6    illustrates an example procedure related to data center access, according to at least one embodiment. 
         FIG.  7    is a block diagram illustrating one pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  8    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  9    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  10    is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. 
         FIG.  11    is a block diagram illustrating an example computer system, according to at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, various embodiments will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described. 
     A cloud service provider (CSP) may provide multiple cloud services to subscribing customers. These services may be provided under different models including a Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), an Infrastructure-as-a-Service (IaaS) model, and others. 
     In the cloud environment, an identity management system is generally provided by the CSP to control user access to resources provided or used by a cloud service. Typical services or functions provided by an identity management system include, without restriction, single-sign on capabilities for users, authentication and authorization services, and other identity-based services. 
     The resources that are protected by an identity management system can be of different types such as compute instances, block storage volumes, virtual cloud networks (VCNs), subnets, route tables, various callable APIs, internal or legacy applications, and the like. These resources include resources stored in the cloud and/or customer on-premise resources. Each resource is typically identified by a unique identifier (e.g., an ID) that is assigned to the resource when the resource is created. 
     A CSP may provide two or more separate and independent identity management systems for their cloud offerings. This may be done, for example, where a first identity management system or platform (e.g., Infrastructure Identity and Access Management (IAM)) may be provided for controlling access to cloud resources for IaaS applications and services provided by the CSP. Separately, a second identity management system or platform (e.g., Identity Cloud Services (IDCS)) may be provided for security and identity management for SaaS and PaaS services provided by the CSP. 
     As a result of providing such two separate platforms, if a customer of the CSP subscribes to both a SaaS or PaaS service and an IaaS service provided by the CSP, the customer generally has two separate accounts—one account with IAM for the IaaS subscription and a separate account with IDCS for the PaaS/SaaS subscription. Each account will have its own credentials, such as user login, password, etc. The same customer thus has two separate sets of credentials for the two accounts. This results in an unsatisfactory customer experience. Additionally, having two separate identity management systems also creates obstacles for interactions between SaaS/PaaS and IaaS services. 
     For purposes of this application, and as an example, the two platforms are referred to as IAM and IDCS. These names and terms are however not intended to be limiting in any manner. The teachings of this disclosure apply to any situation where two (or more) different identity management systems are to be integrated. The identity management systems, services, or platforms to be integrated may be provided by one or more CSPs. 
     In certain embodiments, an integrated identity management platform (referred to as Integrated Identity Management System (IIMS)) is provided that integrates the multiple identity management platforms (e.g., IAM and IDCS platforms) in a manner that is transparent to the users or customers of the cloud services while retaining and offering the various features and functionalities offered by the two separate (e.g., IAM and IDCS) platforms. The integration thus provides a more seamless and enhanced user experience. 
     This integration however is technically very difficult for several reasons. The two platforms may use different procedures and protocols for implementing the identity-related functions. IAM may, for example, be an attribute-based access control (ABAC) system, also known as policy-based access control system, which defines an access control paradigm whereby access rights are granted to users through the use of policies that express a complex Boolean rule set that can evaluate many different attributes. The purpose of ABAC is to protect objects such as data, network devices, and IT resources from unauthorized users and actions—those that do not have “approved” characteristics as defined by an organization&#39;s security policies. On the other hand IDCS may be a role-based access control (RBAC) system which is a policy-neutral access-control mechanism defined around roles and privileges. The components of RBAC such as role-permissions, user-role and role-role relationships make it simple to perform user assignments. As yet another reason, the authentication and authorization frameworks or workflows (e.g., types of tokens that are used, different authentication frameworks such as OAUTH, etc.) used by the two platforms may be different. This is just a small sampling of reasons why providing an integrated solution is technically very difficult. 
     Techniques for customer and/or client (which is referred to collectively as a customer throughout the disclosure) to switch a home region of a CSP are described herein. For example, a CSP may include one or more data centers (which also may be referred to as regions), where each data center may be located in a corresponding geographic area serviced by the CSP. For example, a first data center may be located in a first geographic area serviced by the CSP and a second data center may be located in a second geographic area service by the CSP, where the second geographic area is different from the first geographic area. Each data center may comprise computer hardware and/or software that can provide one or more services to customers. The data centers may store one or more domains, such as identity domains. In some embodiments, the domain may comprise a container that includes data, such as data that indicates access information for the customer and/or services that can be provided to the customer. 
     For a customer, the CSP may have one or more domains corresponding to the customer replicated in multiple data centers. Unluckily, one or more data centers of a CSP may become unavailable (for example, the data centers may be down or services within the data center may be unreachable) during operation. When a customer is utilizing a domain in a first data center that becomes unavailable while the customer is utilizing the data center, the CSP may redirect operation for the customer to the replicated domain in a second data center that is still available. The second data center to which the CSP redirects operation for the customer may be defined by the customer. The CSP may automatically redirect the operation for the customer to the replicated domain in the second data center in response to the first data center becoming unavailable. A domain name system (DNS) address for the domain may indicate both the first data center to which the customer originally signs into the domain and the second data center to which the customer is redirected based on the first data center becoming unavailable. The redirection and/or the implementation of the DNS address may keep the domain available and cause less delay than if the redirection and/or DNS address were not implemented. 
       FIG.  1    illustrates an example CSP arrangement  100 , according to at least one embodiment. The CSP arrangement  100  illustrates an example arrangement illustrating how a user may access a CSP and the services provided by the CSP. 
     The CSP arrangement  100  may include a CSP  102 . The CSP  102  may include hardware and software capable of providing one or more services to customers. For example, the CSP  102  may include one or more computer hardware elements that may implement software to provide one or more defined services to the customers. The CSP  102  may be protected such that authorized customers may be allowed to access the CSP  102  and utilize the services, while unauthorized users may be prevented from accessing the CSP  102  and utilizing the services. 
     The CSP  102  may include one or more data centers. The data centers may comprise computer hardware and/or software. The data centers may make up the CSP  102  and may provide the services. Each of the data centers may correspond to different geographic regions. The CSP  102  may include a first data center  104  and a second data center  106  in an illustrated embodiment. The first data center  104  may be located in a first geographic region and the second data center  106  may be located in a second geographic region. 
     The CSP arrangement  100  may include a customer device  108 . The customer device  108  may comprise a computer device. The customer device  108  may be operated by a customer. The customer may be subscribed with one or more data centers of the CSP  102 . For example, the customer may be subscribed to the first data center  104  and the second data center  106  in the illustrated embodiment. The customer may be able to utilize one or more of the services provided by the data centers to which the customer is subscribed. For example, the customer may be able to utilize one or more of the services provided by the first data center  104  and the second data center  106 . The CSP  102  may maintain an account that indicates the data centers to which the customer is subscribed and/or additional information related to the customer. The account may further include information that can be utilized for authorizing the customer to access the CSP  102 . 
     The data centers may store one or more domains. The domains may be associated with a customer, such as the customer that operates the customer device  108 . In some instances, one or more domains may be replicated in multiple regions. For example, multiple data centers in different regions may store copies of a same domain. In the illustrated embodiment, the first data center  104  may store a first copy of a domain  110  and the second data center  106  may store a second copy of the domain  112 . 
     The CSP arrangement  100  may include a gateway  114 . The gateway  114  may be coupled to one or more data centers of the CSP  102 . The gateway  114  may be located at the edge of the CSP  102  and may provide access to the CSP  102 . For example, the gateway  114  may provide access to the data centers to which the gateway  114  is coupled. In the illustrated embodiment, the gateway  114  is coupled to the first data center  104  and the second data center  106 . The gateway  114  may be able to establish connections between devices and the regions. 
     The data centers coupled to the gateway  114  may correspond to unique domain name system (DNS) addresses. For example, the first data center  104  may correspond to a first DNS address and the second data center  106  may correspond to a second DNS address. In response to the gateway  114  receiving a request from a device that indicates a DNS address, the gateway  114  may establish a connection between the device and the data center corresponding to the DNS address. Each of the data centers may have a common name and an alias name that identifies the particular data center. The alias name may be a name for an Internet protocol (IP) address and may point to a physical machine corresponding to the data center associated with the alias name. The common name may point to another name for the corresponding data center, such as pointing to the alias name associated with the data center or another common name associated with the data center. The common name, and format thereof (e.g., DNS address, string, hexadecimal number, etc.), may be defined by an individual (such as a programmer, an engineer, and/or a user) or the CSP. In the illustrated embodiment, the common names have been defined as DNS addresses. Each of a common name and an alias name for a same data center may be mapped to a same IP address. In the illustrated embodiment, the first data center  104  may be associated with a first alias name  116  of identity.firstregionid.primary.cloud.com. Further, the first data center  104  may be associated with a first common name  118  of identity.firstregionid.cloud.com. The second data center  106  may be associated with a second alias name  120  of identity.secondregion.id.primary.cloud.com in the illustrated embodiment. Further, the second data center  106  may be associated with a second common name  122  of identity.secondregionid.cloud.com. 
     A user of the customer device  108  may input a common name or an alias name corresponding to a data center to access the data center. For example, the customer device  108  may provide the common name or the alias name to the gateway  114  and the gateway  114  may determine which data center is to have a connection established with the customer device  108  based on the common name or the alias name provided to the gateway  114  by the customer device  108 . For example, the gateway  114  may determine that a connection is to be established between the customer device  108  and the first data center  104  based on the customer device  108  providing the first alias name  116  or the first common name  118  to the gateway  114  in the illustrated embodiment. The gateway  114  may determine that a connection is to be established between the customer device  108  and the second data center  106  based on the customer device  108  providing the second alias name  120  or the second common name  122  to the gateway  114 . 
     The approaches described herein may utilize the relationship between the common names and the alias names for the data centers to perform automated and/or simplified updates of the mapping between the common names and the alias names. For example, the approaches described herein may define a common name that may be utilized for automated and/or simplified update of the mapping of the common name from a first alias name to a second alias name in response to a first data center corresponding to the first alias name becoming unavailable. 
       FIG.  2    illustrates an example mapping arrangement  200 , according to at least one embodiment. For example, a mapping arrangement  200  illustrates an address and mappings to alias names that exist while a first data center is available and while the second data center is available. 
     The mapping arrangement  200  includes an address  202 . The address  202  may be defined by a CSP (such as the CSP  102  ( FIG.  1   )) or a customer device (such as the customer device  108  ( FIG.  1   )). The example address  202  is a DNS address that can be utilized for accessing the CSP. The address  202  may be mapped to a plurality of alias names based on states of the data centers associated with the alias names. For example, the address  202  may map to one alias name for one state of the data centers associated with the alias names and may map to another alias name for another state of the data centers. In the illustrated embodiment, the address  202  maps to multiple alias names including a first alias name for a first state of the data centers and a second alias name for a second state of the data centers. 
     More specifically, a first common name within address  202  maps to the first alias name and a second common name within address  202  maps to the second alias name. The address  202  includes a first common name  204  that maps to the first alias name, and a second common name  206  that maps to the second alias name. For example, the first common name  204  of the address  202  may map to a first alias name  208  of identity.firstregionid.primary.cloud.com. The second common name  206  of the address  202  may map to a second alias name  210  of identity.secondregionid.primary.cloud.com. Each of the alias names, which are DNS addresses in the present example, may be mapped to a regional IP address for a corresponding data center. For example, the first alias name  208  may be mapped to a first regional IP address for a first data center and the second alias name  210  may be mapped to a second regional IP address for a second data center. Furthermore, one or more of the alias names may be IP addresses for corresponding data centers. 
     A customer and/or the CSP may define the alias names and/or the data centers to which each common name of the address  202  is mapped. Additionally, one or more of the alias names and/or the data centers may be defined as backups to one or more of the other alias names and/or data centers. For example, the first common name  204  of the address  202  is defined to correspond to a preferred alias name and/or data center. The second common name  206  of the address  202  is defined to correspond to a backup alias name and/or data center, where the backup alias name and/or data center is a backup for the preferred alias name and/or data center. 
     In some embodiments, the customer may select a preferred alias name and/or data center and a backup alias name and/or data center for the address  202 . A customer device (such as the customer device  108  ( FIG.  1   )) operated by the customer may indicate the preferred alias name and/or data center and the backup alias name and/or data center to the CSP. The CSP may generate the address  202  based on the indication of the preferred alias name and/or data center and the backup alias name and/or data center. For example, the CSP may set the first common name  204  to a value (in the illustrated embodiment the value is “firstregionid”) corresponding to the preferred alias name and/or data center. The CSP may set the second common name  206  to a value (in the illustrated embodiment the value is “secondregionid”) corresponding to the backup alias name and/or data center. 
     In some embodiments, the CSP may define a preferred alias name and/or data center and a backup alias name and/or data center for the address  202 . The CSP may define the preferred alias name and/or data center to correspond to a first data center with which the customer subscribed or a data center to which the customer has subscribed that is closest in geographical proximity to the customer. Further, the CSP may define the backup alias name and/or data center to correspond to a second data center with which the customer subscribed or a data center to which the customer has subscribed that is second closest in geographical proximity to the customer. The CSP may set the first common name  204  to a value corresponding to the preferred alias name and/or data center. The CSP may set the second common name  206  to a value corresponding to the backup alias name and/or data center. 
     In some embodiments, the customer device may generate the address and store the address to be utilized for access to the CSP and/or the domains. In other embodiments, the CSP may provide the address  202  to the customer device to be utilized to sign on to the CSP and/or to access the domains. The customer device may store the address for accessing the CSP and/or the domains. 
     When the customer attempts to connect to the CSP, the customer device may provide the address to a gateway (such as the gateway  114  ( FIG.  1   )). The gateway may be configured to process addresses of the format of the address  202 . For example, the gateway may be configured to identify the first common name  204  and the second common name  206  of the address  202 , such as being aware of the locations for the first common name  204  and the second common name  206  within the address  202 . 
     The gateway may store mappings of the common names to the alias names and/or the alias names to IP addresses corresponding to the data centers. The gateway may determine the preferred data center and the backup data center based on the values of the first common name  204 , the second common name  206 , and the stored mappings. The gateway may determine with which of the preferred data center or the backup data center a connection is to be established based on the state of the preferred data center and/or the state of the backup data center. For example, the gateway may determine that the connection is to be established between the customer device and the preferred data center based on the preferred data center being available. Further, the gateway may determine that the connection is to be established between the customer device and the backup data center based on the preferred data center being unavailable. The gateway may establish the determined connection for the customer device to allow the customer device to utilize the services of the CSP. 
       FIG.  3    illustrates an example CSP arrangement  300 , according to at least one embodiment. For example, the CSP arrangement  300  may illustrate a portion of a CSP that can implement approaches for automated fail over described herein. 
     The CSP arrangement  300  may include a first data center  302 . The first data center  302  may be part of a CSP. The first data center  302  may include one or more of the features of the first data center  104  ( FIG.  1   ). For example, the first data center  302  may include computer hardware and/or software that provide services that can be utilized by customers. The first data center  302  may be located in a first geographic region. 
     The CSP arrangement  300  may include a second data center  304 . The second data center  304  may be a part of the CSP. The second data center  304  may include one or more of the features of the second data center  106  ( FIG.  1   ). For example, the second data center  304  may include computer hardware and/or software that provide services that can be utilized by customers. The second data center  304  may be located in a second geographic region. 
     The CSP arrangement  300  may include a customer device  306 . The customer device  306  may be a computer device that can be operated by a customer of the CSP to access the CSP. The customer device  306  may include one or more of the features of the customer device  108  ( FIG.  1   ). 
     The customer operating the customer device  306  may be subscribed to one or more data centers of the CSP. For example, the customer is subscribed to the first data center  302  and the second data center  304  in the illustrated embodiment. The CSP may maintain an account for the customer that may indicate the regions to which the customer is subscribed and/or services that may be accessed by the customer. 
     The CSP may establish one or more domains for the customer on one or more of the data centers of the CSP. In some instances, one or more of the domains for a customer may be replicated among data centers and may provide access to the domains in the data centers to which the domains are replicated. The replicated copies of the domains may have limited functionality as compared to the original copy of the domain, such as the original copy of the domain allowing read and write operations while the replicated copies are limited to read operations. 
     For example, the first data center  302  stores a first copy of a premium domain  308  and a first copy of a default domain  310  associated with the customer in the illustrated embodiment. Further, the first data center  302  stores a first copy of domain metadata and identity and access management (IAM) policy  312  associated with the customer in the illustrated embodiment. The first data center  302  may be defined as a home region for the domains of the customer. Defining the first data center  302  as the home region may cause the copies of the domains stored in the first data center  302  to be the originals from which copies of the domain in other data centers are replicated. Further, the copies of the domains stored in the home region for the customer may provide read operation and write operation capabilities to the customer, such that the customer can cause read and write operations to be implemented to the copies of the domains stored in the home region. Accordingly, the first copy of the premium domain  308 , the first copy of the default domain  310 , and the first copy of the domain metadata and IAM policy  312  are original copies of the domains. The customer can cause read and/or write operations to be implemented to the first copy of the premium domain  308 , the first copy of the default domain  310 , and/or the first copy of the domain metadata and IAM policy  312 . The data center defined as the home region may be referred to as the home region data center. 
     The customer may subscribe to additional data centers of the CSP in addition to the home region data center. The additional data centers to which the customer is subscribed may be referred to as subscribed region data centers. The customer and/or the CSP may define one or more of the domains stored in the home region data center to be replicated in one or more of the subscribed region data centers. The copies of the domains replicated in the subscribed region data centers may provide read only operation to the customer, where the customer can have read operations implemented to the replicated copies of the domain while being prevented from having write operations implemented to the replicated copies of the domain. 
     In the illustrated embodiment, the customer is subscribed to the second data center  304 . The customer and/or the CSP have defined the domains from the first data center  302  to be replicated to the second data center  304 . For example, the first copy of the premium domain  308  is replicated to a second copy of the premium domain  314 , the first copy of the default domain  310  is replicated to a second copy of the default domain  316 , and the first copy of the domain metadata and IAM policy  312  is replicated to a second copy of the domain metadata and IAM policy  318 . Each of the second copy of the premium domain  314 , the second copy of the default domain  316 , and the second copy of the domain metadata and IAM policy  318  may be read only to the customer. 
     The CSP arrangement  300  may include a gateway  320 . The gateway  320  may include one or more of the features of the gateway  114  ( FIG.  1   ). The gateway  320  may be coupled to the customer device  306 , the first data center  302 , and the second data center  304 . The gateway  320  may establish connections between the customer device  306  and the first data center  302  or the customer device  306  and the second data center  304  based on requests from the customer device  306 . For example, the customer device  306  may request a connection with a data center, where the request may include an address, such as the address  202  ( FIG.  2   ). The gateway  320  may determine to establish a connection between the customer device  306  and one of the data centers based on the address provided by the customer device  306 . Each of the data centers may include a console to which the gateway  320  may connect to establish a connection between the customer device  306  and the data center. For example, the first data center  302  includes a first console  322  to which the gateway  320  can establish a connection for accessing the services of the first data center  302 . The second data center  304  includes a second console  324  to which the gateway  320  can establish a connection for accessing the services of the second data center  304 . 
     During operation, the customer device  306  may request a connection with a data center of the CSP. The request provided by the customer device  306  may include an address that maps to a plurality of alias names (such as the address  202 ), where each of the alias names maps to a corresponding data center. For example, the address includes a first common name (such as the first common name  204  ( FIG.  2   )) that maps to a first alias name and a second common name (such as the second common name  206  ( FIG.  2   )) that maps to a second alias name in the illustrated embodiment. The first alias name may map to the first data center  302  and the second alias name may map to the second data center  304 . 
     The gateway  320  may receive the request with the address from the customer device  306 . In some embodiments, the gateway  320  may determine with which of the data centers to establish the connection for the customer device based on the address and states of the data centers. For example, the gateway  320  may determine a preferred data center for accessing a domain and one or more backup data centers for accessing the domain from the address. In the illustrated embodiment, the gateway  320  determines that the first common name corresponds to the preferred data center for a domain and the second common name corresponds to the backup data center for the domain based on the locations of the common names within the address. Based on the first common name corresponding to the first data center  302  and the first common name corresponding to the preferred data center, the gateway  320  determines that the first data center  302  is the preferred data center for the domain. Based on the second common name corresponding to the second data center  304  and the second common name corresponding to the backup data center, the gateway  320  determines that the second data center  304  is a backup data center for the domain. 
     Based on the request, the gateway  320  may determine the states of the first data center  302  and the second data center  304 . For example, the gateway  320  determines whether the first data center  302  is available and the second data center  304  is available. In the illustrated embodiment, the gateway  320  determines that both the first data center  302  and the second data center  304  are available. Accordingly, the gateway  320  determines that the preferred data center is available. The gateway  320  determines that the that the address is to be mapped to the first data center  302  based on the first data center  302  being available and the first data center  302  being the preferred data center. The gateway  320  establishes a connection between the customer device  306  and the first data center  302  based on the request. 
     Once a connection has been established with the first data center  302 , the customer device  306  may have access to the domains stored in the first data center  302 . For example, the customer device  306  can request write operations and/or read operations to be performed with the first copy of the premium domain  308 , the first copy of the default domain  310 , and/or the first copy of the domain metadata and IAM policy  312 . 
       FIG.  4    illustrates an example CSP arrangement  400  with one or more data regions unavailable, according to at least one embodiment. The CSP arrangement  400  may include one or more of the features of the CSP arrangement  300  ( FIG.  3   ). In particular, the CSP arrangement  400  may include the elements of the CSP arrangement  300  with one or more of the elements in a different state than the states described in relation to the CSP arrangement  300 . 
     The CSP arrangement  400  may include a CSP with a first data center  402  and a second data center  404 . The first data center  402  may include one or more of the features of the first data center  302  ( FIG.  3   ). The second data center  404  may include one or more of the features of the second data center  304  ( FIG.  3   ). 
     The CSP arrangement  400  may include a customer device  406 . The customer device  406  may include one or more of the features of the customer device  306  ( FIG.  3   ). The customer device  406  may be operated by the same customer that operates the customer device  306 . Accordingly, the customer may be associated with the same account as described in relation to the customer device  306  and may be subscribed to the first data center  402  and the second data center  404 . 
     The first data center  402  may store one or more domains associated with the customer. The first data center  402  may store a first copy of a premium domain  408 , a first copy of a default domain  410 , and a first copy of a domain metadata and IAM policy  412 . The first copy of the premium domain  408  may include one or more of the features of the first copy of the premium domain  308  ( FIG.  3   ). The first copy of the default domain  410  may include one or more of the features of the first copy of the default domain  310  ( FIG.  3   ). The first copy of the domain metadata and IAM policy  412  may include one or more of the features of the domain metadata and IAM policy  312  ( FIG.  3   ). 
     The second data center  404  may store one or more domains associated with the customer. One or more of the domains stored by the second data center  404  may be replicated domains of the domains stored by the first data center  402 . The second data center  404  may store a second copy of the premium domain  414 , a second copy of the default domain  416 , and a second copy of the domain metadata and IAM policy  418 . The second copy of the premium domain  414  may be replicated from the first copy of the premium domain  480 . The second copy of the default domain  416  may be replicated from the first copy of the default domain  410 . The second copy of the domain metadata and IAM policy  418  may be replicated from the first copy of the domain metadata and IAM policy  412 . 
     The CSP arrangement  400  may include a gateway  420 . The gateway  420  may include one or more of the features of the gateway  320  ( FIG.  3   ). The gateway  420  may be coupled to the customer device  406 , the first data center  402 , and the second data center  404 . The gateway  420  may establish connections between the customer device  406  and the first data center  402 , and/or between the customer device  406  and the second data center  404 . 
     In the illustrated embodiment, the first data center  402  is unavailable (as indicated by the ‘X’ through the first data center  402 ). In some instances, the gateway  420  may have previously established a connection between the customer device  406  and the first data center  402 . The gateway  420  may have established the connection based on an address that included a first common name corresponding to the first data center  402  and a second common name corresponding to the second data center  404 , as described in relation to  FIG.  3   . The address may indicate the first data center  402  as the preferred data center for the domains and the second data center  404  as the backup data center for the domains. The gateway  420  may have maintained the connection until the first data center  402  became unavailable. The connection may have been terminated based on the first data center  402  becoming unavailable. 
     The gateway  420  may determine that the first data center  402  had become unavailable while the connection existed between the customer device  406  and the first data center  402 . The gateway  420  may determine that the connection was improperly terminated based on the first data center  402  becoming unavailable. The gateway  420  may determine that a connection is to be established between the customer device  406  and the backup data center for the domains to which the customer device  406  was connected prior to the first data center  402  becoming unavailable. In some embodiments, the CSP may cause a query to be displayed on the customer device  406  to determine whether a connection to be established between the customer device  406  and the backup data center for the domains, where the CSP may determine whether the connection is to be established based on a response of the customer operating the customer device  406  to the query. In some embodiments, the CSP may wait for a predetermined period of time from the determination that the first data center  402  has become unavailable to determine to establish the connection with the backup center or cause the query to be displayed on the customer device  406 . 
     In response to the gateway  420  determining that a connection is to be established between the customer device  406  and the backup data center, the gateway  420  may determine the backup data center. The gateway  420  may determine the backup data center based on the address utilized for establishing the connection with the first data center  402 . For example, the gateway  420  may have stored the address received in the request or the gateway  420  may request the address from the customer device  406  in response to the determination that the first data center  402  became unavailable. The gateway  420  may determine that the second data center  404  is the backup data center based on the second common name from the address corresponding to the second data center  404 . 
     The gateway  420  may establish the connection between the second data center  404  and the customer device  406  based on the determination that the second data center  404  is the backup data center for the domains of the customer. Once the connection has been established between the second data center  404  and the customer device  406 , the customer device  406  may access the second copy of the premium domain  414 , the second copy of the default domain  416 , and the second copy of the domain metadata and IAM policy  418  stored by the second data center  404 . Due to the second data center  404  being the backup data center rather than being defined as the home region, the operations that the customer device  406  can have implemented with the domains stored by the second data center  404  may be limited. For example, the customer device  406  may be limited to having read operations implemented for the second copy of the premium domain  414 , the second copy of the default domain  416 , and the second copy of the domain metadata and IAM policy  418 , where the customer device  406  may be prevented from having write operations implemented with the domains stored by the second data center  404 . 
     In other instances, the gateway  420  may receive the request to connect with the CSP with the address while the first data center  402  is unavailable. In this instance, the gateway  420  may determine the preferred data center based on the address. For example, the gateway  420  may determine that the first common name of the address corresponds to the preferred data center and indicates the first data center  402 . Accordingly, the gateway  420  may determine that the first data center  402  is the preferred data center based on the address. 
     The gateway  420  may determine that the first data center  402  is unavailable. In some embodiments, the gateway  420  may attempt to establish a connection between the customer device  406  and the first data center  402 . The gateway  420  may determine that the first data center  402  has not responded to attempts to establish the connection and may determine that the first data center  402  is unavailable based on the lack of response from the first data center  402 . In other embodiments, the CSP may update the gateway  420  based on the availability of the data centers and the gateway  420  may determine that the first data center  402  is unavailable based on the indicated availability of the data centers. 
     Based on the determination that the preferred data center is unavailable, the gateway  420  may determine that a connection is to be established with the backup data center. In some embodiments, the CSP may cause a query to be displayed on the customer device  406  that queries whether a connection is to be established with the backup data center. The gateway  420  may determine whether a connection is to be established with the backup data center based on a customer response to the query. 
     Based on the determination that a connection is to be established with the backup data center, the gateway  420  may determine the backup data center for the domains of the customer based on the address. For example, the gateway  420  may identify the second common name from the address and determine that the second common name indicates the backup data center. In the illustrated embodiment, the second common name corresponds to the second data center  404  and indicates that the second data center  404  is the backup data center for the domains for the customer. 
     The gateway  420  may establish the connection between the second data center  404  and the customer device  406  based on the determination that the second data center  404  is the backup data center for the domains of the customer. Once the connection has been established between the second data center  404  and the customer device  406 , the customer device  406  may access the second copy of the premium domain  414 , the second copy of the default domain  416 , and the second copy of the domain metadata and IAM policy  418  stored by the second data center  404 . Due to the second data center  404  being the backup data center rather than being defined as the home region, the operations that the customer device  406  can have implemented with the domains stored by the second data center  404  may be limited. For example, the customer device  406  may be limited to having read operations implemented for the second copy of the premium domain  414 , the second copy of the default domain  416 , and the second copy of the domain metadata and IAM policy  418 , where the customer device  406  may be prevented from having write operations implemented with the domains stored by the second data center  404 . 
     The connection with the backup data center for the customer being established based on the preferred data center becoming unavailable and the address may provide for a faster failover of the domains than legacy approaches. Additionally, utilization of the address that indicates the preferred data centers and one or more backup data centers may be simpler to update the connections than individually having to update the connections for each customer. 
       FIG.  5    illustrates an example address update arrangement  500 , according to at least one embodiment. In some embodiments, the preferred data center and backup data centers indicated by an address may be defined, at least initially, based on data centers with which a customer subscribes. In some embodiments, the customer and/or the CSP may be able to update the preferred data center and/or the backup data centers. An address to be utilized by the customer to access the CSP may be updated based on the changes to the preferred data center and/or the backup data centers. 
     The address update arrangement  500  may include a first address  502 . The first address  502  may be an address to be utilized by a customer for accessing a CSP (such as the CSP  102  ( FIG.  1   ), the CSP described in relation to  FIG.  3   , and/or the CSP described in relation to  FIG.  4   . The first address  502  may include one or more of the features of the address  202  ( FIG.  2   ). The first address  502  may include a first common name  504  and a second common name  506 . 
     The first common name  504  may correspond to a preferred data center for the customer. In the illustrated embodiment, the first common name  504  has a value of firstregionid. The value of the first common name  504  may be mapped to a first alias name. The first alias name may map to a first data center, such as the first data center  302  ( FIG.  3   ) and/or the first data center  402  ( FIG.  1   ). The first common name  504  may indicate that the first data center is the preferred data center for the domains of the customer. 
     The second common name  506  may correspond to a backup data center for the customer. In the illustrated embodiment, the second common name  506  has a value of secondregionid. The value of the second common name  506  may be mapped to a second alias name. The second alias name may map to a second data center, such as the second data center  304  ( FIG.  3   ) and/or the second data center  404  ( FIG.  4   ). The second common name  506  may indicate that the second data center is the backup data center for the domains of the customer. 
     The customer and/or the CSP may request that the preferred data center and/or one or more of the backup data centers for the customer be changed. In the illustrated embodiment, the customer and/or the CSP may request that the backup data center be changed to a third data center. The CSP update arrangement  500  may include an alias name  508  that corresponds to the third data center. 
     The CSP may update the address based on the alias name  508  that corresponds to the third data center and/or the third data center. For example, the CSP may update the first address  502  to a second address  510 . For example, the CSP may update the value of the second common name  506  from the value corresponding to the second data center to a value corresponding to the third data center and/or the alias name  508  corresponding to the third data center. In particular, the CSP may update the second common name  506  to the value of thirdregionid, which corresponds to the third data center. 
     A gateway (such as the gateway  320  ( FIG.  3   ) and/or the gateway  420  ( FIG.  4   )) may determine the data centers that are the preferred data center and/or the backup data centers for a customer based on the address provided. In the case of the first address  502 , the gateway may determine that the first data center is the preferred data center based on the value of the first common name  504  and that the second data center is the backup data center based on the value of the second common name  506 . In the case of the second address  510  after the update, the gateway may determine that the first data center is the preferred data center based on the value of the first common name  504  and that the third data center is the backup data center based on the value of the second common name  506 . 
       FIG.  6    illustrates an example procedure  600  related to data center access, according to at least one embodiment. In particular, the procedure  600  may utilize an address with multiple common names for providing access to a data center. The procedure  600  may be performed by a CSP (such as the CSP  102  ( FIG.  1   ), the CSP described in relation to  FIG.  3   , and/or the CSP described in relation to  FIG.  4   ). 
     In  602 , the CSP may generate an address based at least in part on input from a user device. The input may indicate that a second data center located in a second geographic region is to be utilized as a backup data center for a domain. In some embodiments, generating the address may comprise including a common name corresponding to the second data center located in the second geographic region in the address based at least in part on the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. In some embodiments,  602  may be omitted. 
     In  604 , the CSP may provide access to a domain that resides in a first data center located in a first geographic region. For example, the CSP may provide access to the domain that resides in the first data center located in the first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region. In some embodiments, the address may be a domain name system (DNS) address. 
     In some embodiments, the address may include a first common name that indicates the first data center located in the first geographic region and a second common name that indicates the second data center located in the second geographic region. In some of these embodiments, the first common name may be associated with a first alias name. The first alias name may indicate a regional IP address for access of the domain that resides in the first data center located in the first geographic region. Further, the second common name may be associated with a second alias name. The second alias name may indicate a regional IP address for access of the replica of the domain that resides in the second data center located in the second geographic region. 
     In some embodiments, the address may include a common name for the second data center located in the second geographic region that indicates that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     In  606 , the CSP may determine that the first data center in the first geographic region has become unavailable. The CSP may determine that the first data center in the first geographic region has become available while access to the domain that resides in the first data center is being provided. 
     In  608 , the CSP may determine that the second data center in the second geographic region is to be utilized as a backup data center. For example, the CSP may determine that the second data center in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address. 
     In  610 , the CSP may provide access to a replica of the domain that resides in the second data center in the second geographic region. For example, the CSP may provide access to the replica of the domain based at least in part on the determination that the second data center in the second geographic region is to be utilized as the backup data center and/or the determination that the first data center in the first geographic region has become unavailable. In some embodiments, the replica of the domain may be a copy of the domain replicated from the first data center. 
     In  612 , the CSP may receive an input from a user device associated with the address that indicates a third data center located in a third geographic region is to be utilized as the backup data center. For example, the input may indicate that the third geographic region is to be utilized as the backup data center for the domain. 
     In  614 , the CSP may replace the common name for the second data center with a common name for the third data center. For example, the CSP may replace the common name for the second data center located in the second geographic region within the address with a common name for the third data center located in the third geographic region. The common name for the third data center located in the third geographic region may indicate that the third data center located in the third geographic region is to be utilized as the backup data center for the domain. 
     While  FIG.  6    may arguably suggest an order of the operations of the procedure  600 , it should be understood that the order of the operations of the procedure  600  may be different and/or one or more of the operations may be performed concurrently in other embodiments. Further, it should be understood that one or more of the operations may be omitted from and/or one or more additional operations may be included in the procedure  600  in other embodiments. 
     Example Infrastructure as Service Architectures 
     As noted above, infrastructure as a service (IaaS) is one particular type of cloud computing. IaaS can be configured to provide virtualized computing resources over a public network (e.g., the Internet). In an IaaS model, a cloud computing provider can host the infrastructure components (e.g., servers, storage devices, network nodes (e.g., hardware), deployment software, platform virtualization (e.g., a hypervisor layer), or the like). In some cases, an IaaS provider may also supply a variety of services to accompany those infrastructure components (e.g., billing, monitoring, logging, load balancing and clustering, etc.). Thus, as these services may be policy-driven, IaaS users may be able to implement policies to drive load balancing to maintain application availability and performance. 
     In some instances, IaaS customers may access resources and services through a wide area network (WAN), such as the Internet, and can use the cloud provider&#39;s services to install the remaining elements of an application stack. For example, the user can log in to the IaaS platform to create virtual machines (VMs), install operating systems (OSs) on each VM, deploy middleware such as databases, create storage buckets for workloads and backups, and even install enterprise software into that VM. Customers can then use the provider&#39;s services to perform various functions, including balancing network traffic, troubleshooting application issues, monitoring performance, managing disaster recovery, etc. 
     In most cases, a cloud computing model will require the participation of a cloud provider. The cloud provider may, but need not be, a third-party service that specializes in providing (e.g., offering, renting, selling) IaaS. An entity might also opt to deploy a private cloud, becoming its own provider of infrastructure services. 
     In some examples, IaaS deployment is the process of putting a new application, or a new version of an application, onto a prepared application server or the like. It may also include the process of preparing the server (e.g., installing libraries, daemons, etc.). This is often managed by the cloud provider, below the hypervisor layer (e.g., the servers, storage, network hardware, and virtualization). Thus, the customer may be responsible for handling (OS), middleware, and/or application deployment (e.g., on self-service virtual machines (e.g., that can be spun up on demand) or the like. 
     In some examples, IaaS provisioning may refer to acquiring computers or virtual hosts for use, and even installing needed libraries or services on them. In most cases, deployment does not include provisioning, and the provisioning may need to be performed first. 
     In some cases, there are two different challenges for IaaS provisioning. First, there is the initial challenge of provisioning the initial set of infrastructure before anything is running. Second, there is the challenge of evolving the existing infrastructure (e.g., adding new services, changing services, removing services, etc.) once everything has been provisioned. In some cases, these two challenges may be addressed by enabling the configuration of the infrastructure to be defined declaratively. In other words, the infrastructure (e.g., what components are needed and how they interact) can be defined by one or more configuration files. Thus, the overall topology of the infrastructure (e.g., what resources depend on which, and how they each work together) can be described declaratively. In some instances, once the topology is defined, a workflow can be generated that creates and/or manages the different components described in the configuration files. 
     In some examples, an infrastructure may have many interconnected elements. For example, there may be one or more virtual private clouds (VPCs) (e.g., a potentially on-demand pool of configurable and/or shared computing resources), also known as a core network. In some examples, there may also be one or more inbound/outbound traffic group rules provisioned to define how the inbound and/or outbound traffic of the network will be set up and one or more virtual machines (VMs). Other infrastructure elements may also be provisioned, such as a load balancer, a database, or the like. As more and more infrastructure elements are desired and/or added, the infrastructure may incrementally evolve. 
     In some instances, continuous deployment techniques may be employed to enable deployment of infrastructure code across various virtual computing environments. Additionally, the described techniques can enable infrastructure management within these environments. In some examples, service teams can write code that is desired to be deployed to one or more, but often many, different production environments (e.g., across various different geographic locations, sometimes spanning the entire world). However, in some examples, the infrastructure on which the code will be deployed must first be set up. In some instances, the provisioning can be done manually, a provisioning tool may be utilized to provision the resources, and/or deployment tools may be utilized to deploy the code once the infrastructure is provisioned. 
       FIG.  7    is a block diagram  700  illustrating an example pattern of an IaaS architecture, according to at least one embodiment. Service operators  702  can be communicatively coupled to a secure host tenancy  704  that can include a virtual cloud network (VCN)  706  and a secure host subnet  708 . In some examples, the service operators  702  may be using one or more client computing devices, which may be portable handheld devices (e.g., an iPhone®, cellular telephone, an iPad®, computing tablet, a personal digital assistant (PDA)) or wearable devices (e.g., a Google Glass® head mounted display), running software such as Microsoft Windows Mobile®, and/or a variety of mobile operating systems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, and the like, and being Internet, e-mail, short message service (SMS), Blackberry®, or other communication protocol enabled. Alternatively, the client computing devices can be general purpose personal computers including, by way of example, personal computers and/or laptop computers running various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems. The client computing devices can be workstation computers running any of a variety of commercially-available UNIX® or UNIX-like operating systems, including without limitation the variety of GNU/Linux operating systems, such as for example, Google Chrome OS. Alternatively, or in addition, client computing devices may be any other electronic device, such as a thin-client computer, an Internet-enabled gaming system (e.g., a Microsoft Xbox gaming console with or without a Kinect® gesture input device), and/or a personal messaging device, capable of communicating over a network that can access the VCN  706  and/or the Internet. 
     The VCN  706  can include a local peering gateway (LPG)  710  that can be communicatively coupled to a secure shell (SSH) VCN  712  via an LPG  710  contained in the SSH VCN  712 . The SSH VCN  712  can include an SSH subnet  714 , and the SSH VCN  712  can be communicatively coupled to a control plane VCN  716  via the LPG  710  contained in the control plane VCN  716 . Also, the SSH VCN  712  can be communicatively coupled to a data plane VCN  718  via an LPG  710 . The control plane VCN  716  and the data plane VCN  718  can be contained in a service tenancy  719  that can be owned and/or operated by the IaaS provider. 
     The control plane VCN  716  can include a control plane demilitarized zone (DMZ) tier  720  that acts as a perimeter network (e.g., portions of a corporate network between the corporate intranet and external networks). The DMZ-based servers may have restricted responsibilities and help keep breaches contained. Additionally, the DMZ tier  720  can include one or more load balancer (LB) subnet(s)  722 , a control plane app tier  724  that can include app subnet(s)  726 , a control plane data tier  728  that can include database (DB) subnet(s)  730  (e.g., frontend DB subnet(s) and/or backend DB subnet(s)). The LB subnet(s)  722  contained in the control plane DMZ tier  720  can be communicatively coupled to the app subnet(s)  726  contained in the control plane app tier  724  and an Internet gateway  734  that can be contained in the control plane VCN  716 , and the app subnet(s)  726  can be communicatively coupled to the DB subnet(s)  730  contained in the control plane data tier  728  and a service gateway  736  and a network address translation (NAT) gateway  738 . The control plane VCN  716  can include the service gateway  736  and the NAT gateway  738 . 
     The control plane VCN  716  can include a data plane mirror app tier  740  that can include app subnet(s)  726 . The app subnet(s)  726  contained in the data plane mirror app tier  740  can include a virtual network interface controller (VNIC)  742  that can execute a compute instance  744 . The compute instance  744  can communicatively couple the app subnet(s)  726  of the data plane mirror app tier  740  to app subnet(s)  726  that can be contained in a data plane app tier  746 . 
     The data plane VCN  718  can include the data plane app tier  746 , a data plane DMZ tier  748 , and a data plane data tier  750 . The data plane DMZ tier  748  can include LB subnet(s)  722  that can be communicatively coupled to the app subnet(s)  726  of the data plane app tier  746  and the Internet gateway  734  of the data plane VCN  718 . The app subnet(s)  726  can be communicatively coupled to the service gateway  736  of the data plane VCN  718  and the NAT gateway  738  of the data plane VCN  718 . The data plane data tier  750  can also include the DB subnet(s)  730  that can be communicatively coupled to the app subnet(s)  726  of the data plane app tier  746 . 
     The Internet gateway  734  of the control plane VCN  716  and of the data plane VCN  718  can be communicatively coupled to a metadata management service  752  that can be communicatively coupled to public Internet  754 . Public Internet  754  can be communicatively coupled to the NAT gateway  738  of the control plane VCN  716  and of the data plane VCN  718 . The service gateway  736  of the control plane VCN  716  and of the data plane VCN  718  can be communicatively couple to cloud services  756 . 
     In some examples, the service gateway  736  of the control plane VCN  716  or of the data plane VCN  718  can make application programming interface (API) calls to cloud services  756  without going through public Internet  754 . The API calls to cloud services  756  from the service gateway  736  can be one-way: the service gateway  736  can make API calls to cloud services  756 , and cloud services  756  can send requested data to the service gateway  736 . But, cloud services  756  may not initiate API calls to the service gateway  736 . 
     In some examples, the secure host tenancy  704  can be directly connected to the service tenancy  719 , which may be otherwise isolated. The secure host subnet  708  can communicate with the SSH subnet  714  through an LPG  710  that may enable two-way communication over an otherwise isolated system. Connecting the secure host subnet  708  to the SSH subnet  714  may give the secure host subnet  708  access to other entities within the service tenancy  719 . 
     The control plane VCN  716  may allow users of the service tenancy  719  to set up or otherwise provision desired resources. Desired resources provisioned in the control plane VCN  716  may be deployed or otherwise used in the data plane VCN  718 . In some examples, the control plane VCN  716  can be isolated from the data plane VCN  718 , and the data plane mirror app tier  740  of the control plane VCN  716  can communicate with the data plane app tier  746  of the data plane VCN  718  via VNICs  742  that can be contained in the data plane mirror app tier  740  and the data plane app tier  746 . 
     In some examples, users of the system, or customers, can make requests, for example create, read, update, or delete (CRUD) operations, through public Internet  754  that can communicate the requests to the metadata management service  752 . The metadata management service  752  can communicate the request to the control plane VCN  716  through the Internet gateway  734 . The request can be received by the LB subnet(s)  722  contained in the control plane DMZ tier  720 . The LB subnet(s)  722  may determine that the request is valid, and in response to this determination, the LB subnet(s)  722  can transmit the request to app subnet(s)  726  contained in the control plane app tier  724 . If the request is validated and requires a call to public Internet  754 , the call to public Internet  754  may be transmitted to the NAT gateway  738  that can make the call to public Internet  754 . Metadata that may be desired to be stored by the request can be stored in the DB subnet(s)  730 . 
     In some examples, the data plane mirror app tier  740  can facilitate direct communication between the control plane VCN  716  and the data plane VCN  718 . For example, changes, updates, or other suitable modifications to configuration may be desired to be applied to the resources contained in the data plane VCN  718 . Via a VNIC  742 , the control plane VCN  716  can directly communicate with, and can thereby execute the changes, updates, or other suitable modifications to configuration to, resources contained in the data plane VCN  718 . 
     In some embodiments, the control plane VCN  716  and the data plane VCN  718  can be contained in the service tenancy  719 . In this case, the user, or the customer, of the system may not own or operate either the control plane VCN  716  or the data plane VCN  718 . Instead, the IaaS provider may own or operate the control plane VCN  716  and the data plane VCN  718 , both of which may be contained in the service tenancy  719 . This embodiment can enable isolation of networks that may prevent users or customers from interacting with other users&#39;, or other customers&#39;, resources. Also, this embodiment may allow users or customers of the system to store databases privately without needing to rely on public Internet  754 , which may not have a desired level of threat prevention, for storage. 
     In other embodiments, the LB subnet(s)  722  contained in the control plane VCN  716  can be configured to receive a signal from the service gateway  736 . In this embodiment, the control plane VCN  716  and the data plane VCN  718  may be configured to be called by a customer of the IaaS provider without calling public Internet  754 . Customers of the IaaS provider may desire this embodiment since database(s) that the customers use may be controlled by the IaaS provider and may be stored on the service tenancy  719 , which may be isolated from public Internet  754 . 
       FIG.  8    is a block diagram  800  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  802  (e.g., service operators  702  of  FIG.  7   ) can be communicatively coupled to a secure host tenancy  804  (e.g., the secure host tenancy  704  of  FIG.  7   ) that can include a virtual cloud network (VCN)  806  (e.g., the VCN  706  of  FIG.  7   ) and a secure host subnet  808  (e.g., the secure host subnet  708  of  FIG.  7   ). The VCN  806  can include a local peering gateway (LPG)  810  (e.g., the LPG  710  of  FIG.  7   ) that can be communicatively coupled to a secure shell (SSH) VCN  812  (e.g., the SSH VCN  712  of  FIG.  7   ) via an LPG  710  contained in the SSH VCN  812 . The SSH VCN  812  can include an SSH subnet  814  (e.g., the SSH subnet  714  of  FIG.  7   ), and the SSH VCN  812  can be communicatively coupled to a control plane VCN  816  (e.g., the control plane VCN  716  of  FIG.  7   ) via an LPG  810  contained in the control plane VCN  816 . The control plane VCN  816  can be contained in a service tenancy  819  (e.g., the service tenancy  719  of  FIG.  7   ), and the data plane VCN  818  (e.g., the data plane VCN  718  of  FIG.  7   ) can be contained in a customer tenancy  821  that may be owned or operated by users, or customers, of the system. 
     The control plane VCN  816  can include a control plane DMZ tier  820  (e.g., the control plane DMZ tier  720  of  FIG.  7   ) that can include LB subnet(s)  822  (e.g., LB subnet(s)  722  of  FIG.  7   ), a control plane app tier  824  (e.g., the control plane app tier  724  of  FIG.  7   ) that can include app subnet(s)  826  (e.g., app subnet(s)  726  of  FIG.  7   ), a control plane data tier  828  (e.g., the control plane data tier  728  of  FIG.  7   ) that can include database (DB) subnet(s)  830  (e.g., similar to DB subnet(s)  730  of  FIG.  7   ). The LB subnet(s)  822  contained in the control plane DMZ tier  820  can be communicatively coupled to the app subnet(s)  826  contained in the control plane app tier  824  and an Internet gateway  834  (e.g., the Internet gateway  734  of  FIG.  7   ) that can be contained in the control plane VCN  816 , and the app subnet(s)  826  can be communicatively coupled to the DB subnet(s)  830  contained in the control plane data tier  828  and a service gateway  836  (e.g., the service gateway  736  of  FIG.  7   ) and a network address translation (NAT) gateway  838  (e.g., the NAT gateway  738  of  FIG.  7   ). The control plane VCN  816  can include the service gateway  836  and the NAT gateway  838 . 
     The control plane VCN  816  can include a data plane mirror app tier  840  (e.g., the data plane mirror app tier  740  of  FIG.  7   ) that can include app subnet(s)  826 . The app subnet(s)  826  contained in the data plane mirror app tier  840  can include a virtual network interface controller (VNIC)  842  (e.g., the VNIC of  742 ) that can execute a compute instance  844  (e.g., similar to the compute instance  744  of  FIG.  7   ). The compute instance  844  can facilitate communication between the app subnet(s)  826  of the data plane mirror app tier  840  and the app subnet(s)  826  that can be contained in a data plane app tier  846  (e.g., the data plane app tier  746  of  FIG.  7   ) via the VNIC  842  contained in the data plane mirror app tier  840  and the VNIC  842  contained in the data plane app tier  846 . 
     The Internet gateway  834  contained in the control plane VCN  816  can be communicatively coupled to a metadata management service  852  (e.g., the metadata management service  752  of  FIG.  7   ) that can be communicatively coupled to public Internet  854  (e.g., public Internet  754  of  FIG.  7   ). Public Internet  854  can be communicatively coupled to the NAT gateway  838  contained in the control plane VCN  816 . The service gateway  836  contained in the control plane VCN  816  can be communicatively couple to cloud services  856  (e.g., cloud services  756  of  FIG.  7   ). 
     In some examples, the data plane VCN  818  can be contained in the customer tenancy  821 . In this case, the IaaS provider may provide the control plane VCN  816  for each customer, and the IaaS provider may, for each customer, set up a unique compute instance  844  that is contained in the service tenancy  819 . Each compute instance  844  may allow communication between the control plane VCN  816 , contained in the service tenancy  819 , and the data plane VCN  818  that is contained in the customer tenancy  821 . The compute instance  844  may allow resources, that are provisioned in the control plane VCN  816  that is contained in the service tenancy  819 , to be deployed or otherwise used in the data plane VCN  818  that is contained in the customer tenancy  821 . 
     In other examples, the customer of the IaaS provider may have databases that live in the customer tenancy  821 . In this example, the control plane VCN  816  can include the data plane mirror app tier  840  that can include app subnet(s)  826 . The data plane mirror app tier  840  can reside in the data plane VCN  818 , but the data plane mirror app tier  840  may not live in the data plane VCN  818 . That is, the data plane mirror app tier  840  may have access to the customer tenancy  821 , but the data plane mirror app tier  840  may not exist in the data plane VCN  818  or be owned or operated by the customer of the IaaS provider. The data plane mirror app tier  840  may be configured to make calls to the data plane VCN  818  but may not be configured to make calls to any entity contained in the control plane VCN  816 . The customer may desire to deploy or otherwise use resources in the data plane VCN  818  that are provisioned in the control plane VCN  816 , and the data plane mirror app tier  840  can facilitate the desired deployment, or other usage of resources, of the customer. 
     In some embodiments, the customer of the IaaS provider can apply filters to the data plane VCN  818 . In this embodiment, the customer can determine what the data plane VCN  818  can access, and the customer may restrict access to public Internet  854  from the data plane VCN  818 . The IaaS provider may not be able to apply filters or otherwise control access of the data plane VCN  818  to any outside networks or databases. Applying filters and controls by the customer onto the data plane VCN  818 , contained in the customer tenancy  821 , can help isolate the data plane VCN  818  from other customers and from public Internet  854 . 
     In some embodiments, cloud services  856  can be called by the service gateway  836  to access services that may not exist on public Internet  854 , on the control plane VCN  816 , or on the data plane VCN  818 . The connection between cloud services  856  and the control plane VCN  816  or the data plane VCN  818  may not be live or continuous. Cloud services  856  may exist on a different network owned or operated by the IaaS provider. Cloud services  856  may be configured to receive calls from the service gateway  836  and may be configured to not receive calls from public Internet  854 . Some cloud services  856  may be isolated from other cloud services  856 , and the control plane VCN  816  may be isolated from cloud services  856  that may not be in the same region as the control plane VCN  816 . For example, the control plane VCN  816  may be located in “Region 1,” and cloud service “Deployment 7,” may be located in Region 1 and in “Region 2.” If a call to Deployment 7 is made by the service gateway  836  contained in the control plane VCN  816  located in Region 1, the call may be transmitted to Deployment 7 in Region 1. In this example, the control plane VCN  816 , or Deployment 7 in Region 1, may not be communicatively coupled to, or otherwise in communication with, Deployment 7 in Region 2. 
       FIG.  9    is a block diagram  900  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  902  (e.g., service operators  702  of  FIG.  7   ) can be communicatively coupled to a secure host tenancy  904  (e.g., the secure host tenancy  704  of  FIG.  7   ) that can include a virtual cloud network (VCN)  906  (e.g., the VCN  706  of  FIG.  7   ) and a secure host subnet  908  (e.g., the secure host subnet  708  of  FIG.  7   ). The VCN  906  can include an LPG  910  (e.g., the LPG  710  of  FIG.  7   ) that can be communicatively coupled to an SSH VCN  912  (e.g., the SSH VCN  712  of  FIG.  7   ) via an LPG  910  contained in the SSH VCN  912 . The SSH VCN  912  can include an SSH subnet  914  (e.g., the SSH subnet  714  of  FIG.  7   ), and the SSH VCN  912  can be communicatively coupled to a control plane VCN  916  (e.g., the control plane VCN  716  of  FIG.  7   ) via an LPG  910  contained in the control plane VCN  916  and to a data plane VCN  918  (e.g., the data plane  718  of  FIG.  7   ) via an LPG  910  contained in the data plane VCN  918 . The control plane VCN  916  and the data plane VCN  918  can be contained in a service tenancy  919  (e.g., the service tenancy  719  of  FIG.  7   ). 
     The control plane VCN  916  can include a control plane DMZ tier  920  (e.g., the control plane DMZ tier  720  of  FIG.  7   ) that can include load balancer (LB) subnet(s)  922  (e.g., LB subnet(s)  722  of  FIG.  7   ), a control plane app tier  924  (e.g., the control plane app tier  724  of  FIG.  7   ) that can include app subnet(s)  926  (e.g., similar to app subnet(s)  726  of  FIG.  7   ), a control plane data tier  928  (e.g., the control plane data tier  728  of  FIG.  7   ) that can include DB subnet(s)  930 . The LB subnet(s)  922  contained in the control plane DMZ tier  920  can be communicatively coupled to the app subnet(s)  926  contained in the control plane app tier  924  and to an Internet gateway  934  (e.g., the Internet gateway  734  of  FIG.  7   ) that can be contained in the control plane VCN  916 , and the app subnet(s)  926  can be communicatively coupled to the DB subnet(s)  930  contained in the control plane data tier  928  and to a service gateway  936  (e.g., the service gateway of  FIG.  7   ) and a network address translation (NAT) gateway  938  (e.g., the NAT gateway  738  of  FIG.  7   ). The control plane VCN  916  can include the service gateway  936  and the NAT gateway  938 . 
     The data plane VCN  918  can include a data plane app tier  946  (e.g., the data plane app tier  746  of  FIG.  7   ), a data plane DMZ tier  948  (e.g., the data plane DMZ tier  748  of  FIG.  7   ), and a data plane data tier  950  (e.g., the data plane data tier  750  of  FIG.  7   ). The data plane DMZ tier  948  can include LB subnet(s)  922  that can be communicatively coupled to trusted app subnet(s)  960  and untrusted app subnet(s)  962  of the data plane app tier  946  and the Internet gateway  934  contained in the data plane VCN  918 . The trusted app subnet(s)  960  can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918 , the NAT gateway  938  contained in the data plane VCN  918 , and DB subnet(s)  930  contained in the data plane data tier  950 . The untrusted app subnet(s)  962  can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918  and DB subnet(s)  930  contained in the data plane data tier  950 . The data plane data tier  950  can include DB subnet(s)  930  that can be communicatively coupled to the service gateway  936  contained in the data plane VCN  918 . 
     The untrusted app subnet(s)  962  can include one or more primary VNICs  964 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  966 ( 1 )-(N). Each tenant VM  966 ( 1 )-(N) can be communicatively coupled to a respective app subnet  967 ( 1 )-(N) that can be contained in respective container egress VCNs  968 ( 1 )-(N) that can be contained in respective customer tenancies  970 ( 1 )-(N). Respective secondary VNICs  972 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  962  contained in the data plane VCN  918  and the app subnet contained in the container egress VCNs  968 ( 1 )-(N). Each container egress VCNs  968 ( 1 )-(N) can include a NAT gateway  938  that can be communicatively coupled to public Internet  954  (e.g., public Internet  754  of  FIG.  7   ). 
     The Internet gateway  934  contained in the control plane VCN  916  and contained in the data plane VCN  918  can be communicatively coupled to a metadata management service  952  (e.g., the metadata management system  752  of  FIG.  7   ) that can be communicatively coupled to public Internet  954 . Public Internet  954  can be communicatively coupled to the NAT gateway  938  contained in the control plane VCN  916  and contained in the data plane VCN  918 . The service gateway  936  contained in the control plane VCN  916  and contained in the data plane VCN  918  can be communicatively couple to cloud services  956 . 
     In some embodiments, the data plane VCN  918  can be integrated with customer tenancies  970 . This integration can be useful or desirable for customers of the IaaS provider in some cases such as a case that may desire support when executing code. The customer may provide code to run that may be destructive, may communicate with other customer resources, or may otherwise cause undesirable effects. In response to this, the IaaS provider may determine whether to run code given to the IaaS provider by the customer. 
     In some examples, the customer of the IaaS provider may grant temporary network access to the IaaS provider and request a function to be attached to the data plane app tier  946 . Code to run the function may be executed in the VMs  966 ( 1 )-(N), and the code may not be configured to run anywhere else on the data plane VCN  918 . Each VM  966 ( 1 )-(N) may be connected to one customer tenancy  970 . Respective containers  971 ( 1 )-(N) contained in the VMs  966 ( 1 )-(N) may be configured to run the code. In this case, there can be a dual isolation (e.g., the containers  971 ( 1 )-(N) running code, where the containers  971 ( 1 )-(N) may be contained in at least the VM  966 ( 1 )-(N) that are contained in the untrusted app subnet(s)  962 ), which may help prevent incorrect or otherwise undesirable code from damaging the network of the IaaS provider or from damaging a network of a different customer. The containers  971 ( 1 )-(N) may be communicatively coupled to the customer tenancy  970  and may be configured to transmit or receive data from the customer tenancy  970 . The containers  971 ( 1 )-(N) may not be configured to transmit or receive data from any other entity in the data plane VCN  918 . Upon completion of running the code, the IaaS provider may kill or otherwise dispose of the containers  971 ( 1 )-(N). 
     In some embodiments, the trusted app subnet(s)  960  may run code that may be owned or operated by the IaaS provider. In this embodiment, the trusted app subnet(s)  960  may be communicatively coupled to the DB subnet(s)  930  and be configured to execute CRUD operations in the DB subnet(s)  930 . The untrusted app subnet(s)  962  may be communicatively coupled to the DB subnet(s)  930 , but in this embodiment, the untrusted app subnet(s) may be configured to execute read operations in the DB subnet(s)  930 . The containers  971 ( 1 )-(N) that can be contained in the VM  966 ( 1 )-(N) of each customer and that may run code from the customer may not be communicatively coupled with the DB subnet(s)  930 . 
     In other embodiments, the control plane VCN  916  and the data plane VCN  918  may not be directly communicatively coupled. In this embodiment, there may be no direct communication between the control plane VCN  916  and the data plane VCN  918 . However, communication can occur indirectly through at least one method. An LPG  910  may be established by the IaaS provider that can facilitate communication between the control plane VCN  916  and the data plane VCN  918 . In another example, the control plane VCN  916  or the data plane VCN  918  can make a call to cloud services  956  via the service gateway  936 . For example, a call to cloud services  956  from the control plane VCN  916  can include a request for a service that can communicate with the data plane VCN  918 . 
       FIG.  10    is a block diagram  1000  illustrating another example pattern of an IaaS architecture, according to at least one embodiment. Service operators  1002  (e.g., service operators  702  of  FIG.  7   ) can be communicatively coupled to a secure host tenancy  1004  (e.g., the secure host tenancy  704  of  FIG.  7   ) that can include a virtual cloud network (VCN)  1006  (e.g., the VCN  706  of  FIG.  7   ) and a secure host subnet  1008  (e.g., the secure host subnet  708  of  FIG.  7   ). The VCN  1006  can include an LPG  1010  (e.g., the LPG  710  of  FIG.  7   ) that can be communicatively coupled to an SSH VCN  1012  (e.g., the SSH VCN  712  of  FIG.  7   ) via an LPG  1010  contained in the SSH VCN  1012 . The SSH VCN  1012  can include an SSH subnet  1014  (e.g., the SSH subnet  714  of  FIG.  7   ), and the SSH VCN  1012  can be communicatively coupled to a control plane VCN  1016  (e.g., the control plane VCN  716  of  FIG.  7   ) via an LPG  1010  contained in the control plane VCN  1016  and to a data plane VCN  1018  (e.g., the data plane  718  of  FIG.  7   ) via an LPG  1010  contained in the data plane VCN  1018 . The control plane VCN  1016  and the data plane VCN  1018  can be contained in a service tenancy  1019  (e.g., the service tenancy  719  of  FIG.  7   ). 
     The control plane VCN  1016  can include a control plane DMZ tier  1020  (e.g., the control plane DMZ tier  720  of  FIG.  7   ) that can include LB subnet(s)  1022  (e.g., LB subnet(s)  722  of  FIG.  7   ), a control plane app tier  1024  (e.g., the control plane app tier  724  of  FIG.  7   ) that can include app subnet(s)  1026  (e.g., app subnet(s)  726  of  FIG.  7   ), a control plane data tier  1028  (e.g., the control plane data tier  728  of  FIG.  7   ) that can include DB subnet(s)  1030  (e.g., DB subnet(s)  930  of  FIG.  9   ). The LB subnet(s)  1022  contained in the control plane DMZ tier  1020  can be communicatively coupled to the app subnet(s)  1026  contained in the control plane app tier  1024  and to an Internet gateway  1034  (e.g., the Internet gateway  734  of  FIG.  7   ) that can be contained in the control plane VCN  1016 , and the app subnet(s)  1026  can be communicatively coupled to the DB subnet(s)  1030  contained in the control plane data tier  1028  and to a service gateway  1036  (e.g., the service gateway of  FIG.  7   ) and a network address translation (NAT) gateway  1038  (e.g., the NAT gateway  738  of  FIG.  7   ). The control plane VCN  1016  can include the service gateway  1036  and the NAT gateway  1038 . 
     The data plane VCN  1018  can include a data plane app tier  1046  (e.g., the data plane app tier  746  of  FIG.  7   ), a data plane DMZ tier  1048  (e.g., the data plane DMZ tier  748  of  FIG.  7   ), and a data plane data tier  1050  (e.g., the data plane data tier  750  of  FIG.  7   ). The data plane DMZ tier  1048  can include LB subnet(s)  1022  that can be communicatively coupled to trusted app subnet(s)  1060  (e.g., trusted app subnet(s)  960  of  FIG.  9   ) and untrusted app subnet(s)  1062  (e.g., untrusted app subnet(s)  962  of  FIG.  9   ) of the data plane app tier  1046  and the Internet gateway  1034  contained in the data plane VCN  1018 . The trusted app subnet(s)  1060  can be communicatively coupled to the service gateway  1036  contained in the data plane VCN  1018 , the NAT gateway  1038  contained in the data plane VCN  1018 , and DB subnet(s)  1030  contained in the data plane data tier  1050 . The untrusted app subnet(s)  1062  can be communicatively coupled to the service gateway  1036  contained in the data plane VCN  1018  and DB subnet(s)  1030  contained in the data plane data tier  1050 . The data plane data tier  1050  can include DB subnet(s)  1030  that can be communicatively coupled to the service gateway  1036  contained in the data plane VCN  1018 . 
     The untrusted app subnet(s)  1062  can include primary VNICs  1064 ( 1 )-(N) that can be communicatively coupled to tenant virtual machines (VMs)  1066 ( 1 )-(N) residing within the untrusted app subnet(s)  1062 . Each tenant VM  1066 ( 1 )-(N) can run code in a respective container  1067 ( 1 )-(N), and be communicatively coupled to an app subnet  1026  that can be contained in a data plane app tier  1046  that can be contained in a container egress VCN  1068 . Respective secondary VNICs  1072 ( 1 )-(N) can facilitate communication between the untrusted app subnet(s)  1062  contained in the data plane VCN  1018  and the app subnet contained in the container egress VCN  1068 . The container egress VCN can include a NAT gateway  1038  that can be communicatively coupled to public Internet  1054  (e.g., public Internet  754  of  FIG.  7   ). 
     The Internet gateway  1034  contained in the control plane VCN  1016  and contained in the data plane VCN  1018  can be communicatively coupled to a metadata management service  1052  (e.g., the metadata management system  752  of  FIG.  7   ) that can be communicatively coupled to public Internet  1054 . Public Internet  1054  can be communicatively coupled to the NAT gateway  1038  contained in the control plane VCN  1016  and contained in the data plane VCN  1018 . The service gateway  1036  contained in the control plane VCN  1016  and contained in the data plane VCN  1018  can be communicatively couple to cloud services  1056 . 
     In some examples, the pattern illustrated by the architecture of block diagram  1000  of  FIG.  10    may be considered an exception to the pattern illustrated by the architecture of block diagram  900  of  FIG.  9    and may be desirable for a customer of the IaaS provider if the IaaS provider cannot directly communicate with the customer (e.g., a disconnected region). The respective containers  1067 ( 1 )-(N) that are contained in the VMs  1066 ( 1 )-(N) for each customer can be accessed in real-time by the customer. The containers  1067 ( 1 )-(N) may be configured to make calls to respective secondary VNICs  1072 ( 1 )-(N) contained in app subnet(s)  1026  of the data plane app tier  1046  that can be contained in the container egress VCN  1068 . The secondary VNICs  1072 ( 1 )-(N) can transmit the calls to the NAT gateway  1038  that may transmit the calls to public Internet  1054 . In this example, the containers  1067 ( 1 )-(N) that can be accessed in real-time by the customer can be isolated from the control plane VCN  1016  and can be isolated from other entities contained in the data plane VCN  1018 . The containers  1067 ( 1 )-(N) may also be isolated from resources from other customers. 
     In other examples, the customer can use the containers  1067 ( 1 )-(N) to call cloud services  1056 . In this example, the customer may run code in the containers  1067 ( 1 )-(N) that requests a service from cloud services  1056 . The containers  1067 ( 1 )-(N) can transmit this request to the secondary VNICs  1072 ( 1 )-(N) that can transmit the request to the NAT gateway that can transmit the request to public Internet  1054 . Public Internet  1054  can transmit the request to LB subnet(s)  1022  contained in the control plane VCN  1016  via the Internet gateway  1034 . In response to determining the request is valid, the LB subnet(s) can transmit the request to app subnet(s)  1026  that can transmit the request to cloud services  1056  via the service gateway  1036 . 
     It should be appreciated that IaaS architectures  700 ,  800 ,  900 ,  1000  depicted in the figures may have other components than those depicted. Further, the embodiments shown in the figures are only some examples of a cloud infrastructure system that may incorporate an embodiment of the disclosure. In some other embodiments, the IaaS systems may have more or fewer components than shown in the figures, may combine two or more components, or may have a different configuration or arrangement of components. 
     In certain embodiments, the IaaS systems described herein may include a suite of applications, middleware, and database service offerings that are delivered to a customer in a self-service, subscription-based, elastically scalable, reliable, highly available, and secure manner. An example of such an IaaS system is the Oracle Cloud Infrastructure (OCI) provided by the present assignee. 
       FIG.  11    illustrates an example computer system  1100 , in which various embodiments may be implemented. The system  1100  may be used to implement any of the computer systems described above. As shown in the figure, computer system  1100  includes a processing unit  1104  that communicates with a number of peripheral subsystems via a bus subsystem  1102 . These peripheral subsystems may include a processing acceleration unit  1106 , an I/O subsystem  1108 , a storage subsystem  1118  and a communications subsystem  1124 . Storage subsystem  1118  includes tangible computer-readable storage media  1122  and a system memory  1110 . 
     Bus subsystem  1102  provides a mechanism for letting the various components and subsystems of computer system  1100  communicate with each other as intended. Although bus subsystem  1102  is shown schematically as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem  1102  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include an Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, which can be implemented as a Mezzanine bus manufactured to the IEEE P1386.1 standard. 
     Processing unit  1104 , which can be implemented as one or more integrated circuits (e.g., a conventional microprocessor or microcontroller), controls the operation of computer system  1100 . One or more processors may be included in processing unit  1104 . These processors may include single core or multicore processors. In certain embodiments, processing unit  1104  may be implemented as one or more independent processing units  1132  and/or  1134  with single or multicore processors included in each processing unit. In other embodiments, processing unit  1104  may also be implemented as a quad-core processing unit formed by integrating two dual-core processors into a single chip. 
     In various embodiments, processing unit  1104  can execute a variety of programs in response to program code and can maintain multiple concurrently executing programs or processes. At any given time, some or all of the program code to be executed can be resident in processor(s)  1104  and/or in storage subsystem  1118 . Through suitable programming, processor(s)  1104  can provide various functionalities described above. Computer system  1100  may additionally include a processing acceleration unit  1106 , which can include a digital signal processor (DSP), a special-purpose processor, and/or the like. 
     I/O subsystem  1108  may include user interface input devices and user interface output devices. User interface input devices may include a keyboard, pointing devices such as a mouse or trackball, a touchpad or touch screen incorporated into a display, a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, audio input devices with voice command recognition systems, microphones, and other types of input devices. User interface input devices may include, for example, motion sensing and/or gesture recognition devices such as the Microsoft Kinect® motion sensor that enables users to control and interact with an input device, such as the Microsoft Xbox® 360 game controller, through a natural user interface using gestures and spoken commands. User interface input devices may also include eye gesture recognition devices such as the Google Glass® blink detector that detects eye activity (e.g., ‘blinking’ while taking pictures and/or making a menu selection) from users and transforms the eye gestures as input into an input device (e.g., Google Glass®). Additionally, user interface input devices may include voice recognition sensing devices that enable users to interact with voice recognition systems (e.g., Siri® navigator), through voice commands. 
     User interface input devices may also include, without limitation, three dimensional (3D) mice, joysticks or pointing sticks, gamepads and graphic tablets, and audio/visual devices such as speakers, digital cameras, digital camcorders, portable media players, webcams, image scanners, fingerprint scanners, barcode reader 3D scanners, 3D printers, laser rangefinders, and eye gaze tracking devices. Additionally, user interface input devices may include, for example, medical imaging input devices such as computed tomography, magnetic resonance imaging, position emission tomography, medical ultrasonography devices. User interface input devices may also include, for example, audio input devices such as MIDI keyboards, digital musical instruments and the like. 
     User interface output devices may include a display subsystem, indicator lights, or non-visual displays such as audio output devices, etc. The display subsystem may be a cathode ray tube (CRT), a flat-panel device, such as that using a liquid crystal display (LCD) or plasma display, a projection device, a touch screen, and the like. In general, use of the term “output device” is intended to include all possible types of devices and mechanisms for outputting information from computer system  1100  to a user or other computer. For example, user interface output devices may include, without limitation, a variety of display devices that visually convey text, graphics and audio/video information such as monitors, printers, speakers, headphones, automotive navigation systems, plotters, voice output devices, and modems. 
     Computer system  1100  may comprise a storage subsystem  1118  that comprises software elements, shown as being currently located within a system memory  1110 . System memory  1110  may store program instructions that are loadable and executable on processing unit  1104 , as well as data generated during the execution of these programs. 
     Depending on the configuration and type of computer system  1100 , system memory  1110  may be volatile (such as random access memory (RAM)) and/or non-volatile (such as read-only memory (ROM), flash memory, etc.) The RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated and executed by processing unit  1104 . In some implementations, system memory  1110  may include multiple different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some implementations, a basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computer system  1100 , such as during start-up, may typically be stored in the ROM. By way of example, and not limitation, system memory  1110  also illustrates application programs  1112 , which may include client applications, Web browsers, mid-tier applications, relational database management systems (RDBMS), etc., program data  1114 , and an operating system  1116 . By way of example, operating system  1116  may include various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems, a variety of commercially-available UNIX® or UNIX-like operating systems (including without limitation the variety of GNU/Linux operating systems, the Google Chrome® OS, and the like) and/or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® OS, and Palm® OS operating systems. 
     Storage subsystem  1118  may also provide a tangible computer-readable storage medium for storing the basic programming and data constructs that provide the functionality of some embodiments. Software (programs, code modules, instructions) that when executed by a processor provide the functionality described above may be stored in storage subsystem  1118 . These software modules or instructions may be executed by processing unit  1104 . Storage subsystem  1118  may also provide a repository for storing data used in accordance with the present disclosure. 
     Storage subsystem  1100  may also include a computer-readable storage media reader  1120  that can further be connected to computer-readable storage media  1122 . Together and, optionally, in combination with system memory  1110 , computer-readable storage media  1122  may comprehensively represent remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing, storing, transmitting, and retrieving computer-readable information. 
     Computer-readable storage media  1122  containing code, or portions of code, can also include any appropriate media known or used in the art, including storage media and communication media, such as but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage and/or transmission of information. This can include tangible computer-readable storage media such as RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer readable media. This can also include nontangible computer-readable media, such as data signals, data transmissions, or any other medium which can be used to transmit the desired information and which can be accessed by computing system  1100 . 
     By way of example, computer-readable storage media  1122  may include a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD ROM, DVD, and Blu-Ray® disk, or other optical media. Computer-readable storage media  1122  may include, but is not limited to, Zip® drives, flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tape, and the like. Computer-readable storage media  1122  may also include, solid-state drives (SSD) based on non-volatile memory such as flash-memory based SSDs, enterprise flash drives, solid state ROM, and the like, SSDs based on volatile memory such as solid state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs that use a combination of DRAM and flash memory based SSDs. The disk drives and their associated computer-readable media may provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for computer system  1100 . 
     Communications subsystem  1124  provides an interface to other computer systems and networks. Communications subsystem  1124  serves as an interface for receiving data from and transmitting data to other systems from computer system  1100 . For example, communications subsystem  1124  may enable computer system  1100  to connect to one or more devices via the Internet. In some embodiments communications subsystem  1124  can include radio frequency (RF) transceiver components for accessing wireless voice and/or data networks (e.g., using cellular telephone technology, advanced data network technology, such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.11 family standards, or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and/or other components. In some embodiments communications subsystem  1124  can provide wired network connectivity (e.g., Ethernet) in addition to or instead of a wireless interface. 
     In some embodiments, communications subsystem  1124  may also receive input communication in the form of structured and/or unstructured data feeds  1126 , event streams  1128 , event updates  1130 , and the like on behalf of one or more users who may use computer system  1100 . 
     By way of example, communications subsystem  1124  may be configured to receive data feeds  1126  in real-time from users of social networks and/or other communication services such as Twitter® feeds, Facebook® updates, web feeds such as Rich Site Summary (RSS) feeds, and/or real-time updates from one or more third party information sources. 
     Additionally, communications subsystem  1124  may also be configured to receive data in the form of continuous data streams, which may include event streams  1128  of real-time events and/or event updates  1130 , that may be continuous or unbounded in nature with no explicit end. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measuring tools (e.g., network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like. 
     Communications subsystem  1124  may also be configured to output the structured and/or unstructured data feeds  1126 , event streams  1128 , event updates  1130 , and the like to one or more databases that may be in communication with one or more streaming data source computers coupled to computer system  1100 . 
     Computer system  1100  can be one of various types, including a handheld portable device (e.g., an iPhone® cellular phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a PC, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system. 
     Due to the ever-changing nature of computers and networks, the description of computer system  1100  depicted in the figure is intended only as a specific example. Many other configurations having more or fewer components than the system depicted in the figure are possible. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, firmware, software (including applets), or a combination. Further, connection to other computing devices, such as network input/output devices, may be employed. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments. 
     Although specific embodiments have been described, various modifications, alterations, alternative constructions, and equivalents are also encompassed within the scope of the disclosure. Embodiments are not restricted to operation within certain specific data processing environments, but are free to operate within a plurality of data processing environments. Additionally, although embodiments have been described using a particular series of transactions and steps, it should be apparent to those skilled in the art that the scope of the present disclosure is not limited to the described series of transactions and steps. Various features and aspects of the above-described embodiments may be used individually or jointly. 
     Further, while embodiments have been described using a particular combination of hardware and software, it should be recognized that other combinations of hardware and software are also within the scope of the present disclosure. Embodiments may be implemented only in hardware, or only in software, or using combinations thereof. The various processes described herein can be implemented on the same processor or different processors in any combination. Accordingly, where components or modules are described as being configured to perform certain operations, such configuration can be accomplished, e.g., by designing electronic circuits to perform the operation, by programming programmable electronic circuits (such as microprocessors) to perform the operation, or any combination thereof. Processes can communicate using a variety of techniques including but not limited to conventional techniques for inter process communication, and different pairs of processes may use different techniques, or the same pair of processes may use different techniques at different times. 
     The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, deletions, and other modifications and changes may be made thereunto without departing from the broader spirit and scope as set forth in the claims. Thus, although specific disclosure embodiments have been described, these are not intended to be limiting. Various modifications and equivalents are within the scope of the following claims. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosed embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure. 
     Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is intended to be understood within the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present. 
     Preferred embodiments of this disclosure are described herein, including the best mode known for carrying out the disclosure. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. Those of ordinary skill should be able to employ such variations as appropriate and the disclosure may be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     EXAMPLES 
     In the following sections, further exemplary embodiments are provided. 
     Example 1 may include a method for failover of a domain, comprising providing, by a cloud service provider (CSP), access to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region, determining, by the cloud service provider, that the first data center in the first geographic region has become unavailable, determining, by the cloud service provider, that the second data center in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address, and providing, by the cloud service provider, access to a replica of the domain that resides in the second data center in the second geographic region based at least in part on a) the determination that the second data center in the second geographic region is to be utilized as the backup data center and b) the determination that the first data center in the first geographic region has become unavailable. 
     Example 2 may include the method of example 1, wherein the address is a domain name system (DNS) address. 
     Example 3 may include the method of example 1, wherein the address comprises a first common name that indicates the first data center located in the first geographic region and a second common name that indicates the second data center located in the second geographic region. 
     Example 4 may include the method of example 3, wherein the first common name is associated with a first alias name, wherein the first alias name indicates a regional Internet protocol (IP) address for access of the domain that resides in the first data center located in the first geographic region, wherein the second common name is associated with a second alias name, and wherein the second alias name indicates a regional Internet protocol address for access of the replica of the domain that resides in the second data center located in the second geographic region. 
     Example 5 may include the method of example 1, further comprising generating, by the cloud service provider, the address based at least in part on input from a user device, the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     Example 6 may include the method of example 5, wherein generating the address comprises including a common name corresponding to the second data center located in the second geographic region in the address based at least in part on the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     Example 7 may include the method of example 1, wherein the address includes a common name for the second data center located in the second geographic region that indicates that the second data center located in the second geographic region is to be utilized as the backup data center for the domain, wherein the method further comprises receiving, by the cloud service provider, an input from a user device associated with the address that indicates a third data center located in a third geographic region is to be utilized as the backup data center for the domain, and replacing, by the cloud service provider, the common name for the second data center located in the second geographic region within the address with a common name for the third data center located in the third geographic region, wherein the common name for the third data center located in the third geographic region indicates that the third data center located in the third geographic region is to be utilized as the backup data center for the domain. 
     Example 8 may include one or more non-transitory computer-readable media having instructions stored thereon, wherein the instructions, when executed by one or more processors, cause a cloud service provider (CSP) to provide access to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region, determine that the first data center located in the first geographic region has become unavailable, determine that the second data center located in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address, and provide access to a replica of the domain that resides in the second data center located in the second geographic region based at least in part on the determination that the second data center located in the second geographic region is to be utilized as the backup data center and the determination that the first data center located in the first geographic region has become unavailable. 
     Example 9 may include the one or more non-transitory computer-readable media of example 8, wherein the address is a domain name system (DNS) address. 
     Example 10 may include the one or more non-transitory computer-readable media of example 8, wherein the address comprises a first common name that indicates the first data center located in the first geographic region and a second common name that indicates the second data center located in the second geographic region. 
     Example 11 may include the one or more non-transitory computer-readable media of example 10, wherein the first common name is associated with a first alias name, wherein the first alias name indicates a regional Internet protocol (IP) address for access of the domain that resides in the first data center located in the first geographic region, wherein the second common name is associated with a second alias name, and wherein the second alias name indicates a regional IP address for access of the replica of the domain that resides in the second data center located in the second geographic region. 
     Example 12 may include the one or more non-transitory computer-readable media of example 8, wherein the instructions, when executed by the one or more processors, further causes the cloud service provider to generate the address based at least in part on input from a user device, the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     Example 13 may include the one or more non-transitory computer-readable media of example 12, wherein to generate the address comprises to include a common name corresponding to the second data center located in the second geographic region in the address based at least in part on the input indicating that the second data center located in second region is to be utilized as the backup data center for the domain. 
     Example 14 may include the one or more non-transitory computer-readable media of example 8, wherein the address includes a common name for the second data center located in the second geographic region that indicates that the second data center located in the second geographic region is to be utilized as the backup data center for the domain, wherein the instructions, when executed by the one or more processors, further cause the cloud service provider to receive an input from a user device associated with the address that indicates a third data center located in a third geographic region to be utilized as the backup data center for the domain, and replace the common name for the second data center located in the second geographic region within the address with a common name for the third data center located in the third geographic region, wherein the common name for the third data center located in the third geographic region indicates that the third data center located in the third geographic region is to be utilized as the backup data center for the domain. 
     Example 15 may include a cloud service provider (CSP), comprising one or more data centers located in one or more geographic regions to provide services to one or more user devices, and one or more processors to control access to the one or more data centers located in the one or more geographic regions, the one or more processors to cause access to be provided to a domain that resides in a first data center located in a first geographic region based at least in part on an address that indicates the first data center located in the first geographic region and a second data center located in a second geographic region, determine that the first data center located in the first geographic region has become unavailable, determine that the second data center located in the second geographic region is to be utilized as a backup data center for the domain based at least in part on the address, and cause access to be provided to a replica of the domain that resides in the second data center located in the second geographic region based at least in part on the determination that the first data center located in the first geographic region has become unavailable. 
     Example 16 may include the cloud service provider of example 15, wherein the address is a domain name system (DNS) address. 
     Example 17 may include the cloud service provider of example 15, wherein the address comprises a first common name that indicates the first data center located in the first geographic region and a second common name that indicates the second data center located in the second geographic region. 
     Example 18 may include the cloud service provider of example 17, wherein the first common name is associated with a first alias name, wherein the first alias name indicates a regional Internet protocol (IP) address for access of the domain that resides in the first data center located in the first geographic region, wherein the second common name is associated with a second alias name, and wherein the second alias name indicates a regional Internet protocol address for access of the replica of the domain that resides in the second data center located in the second geographic region. 
     Example 19 may include the cloud service provider of example 15, wherein the one or more processors are further to generate the address based at least in part on input from a user device, the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     Example 20 may include the cloud service provider of example 19, wherein to generate the address comprises to include a common name corresponding to the second data center located in the second geographic region in the address based at least in part on the input indicating that the second data center located in the second geographic region is to be utilized as the backup data center for the domain. 
     In the foregoing specification, aspects of the disclosure are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the disclosure is not limited thereto. Various features and aspects of the above-described disclosure may be used individually or jointly. Further, embodiments can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive.