Patent Publication Number: US-2021182095-A1

Title: Methods and systems for automating deployment of applications in a multi-tenant database environment

Description:
CLAIM OF PRIORITY 
     This divisional application is related to, and claims priority to, the divisional application entitled, “METHODS AND SYSTEMS FOR AUTOMATING DEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,” filed on Nov. 12, 2019, having an application number of Ser. No. 16/681,017 and attorney docket No. 37633.6023D3; the divisional application entitled, “METHODS AND SYSTEMS FOR AUTOMATING DEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,” filed on Nov. 30, 2016, having an application number of Ser. No. 15/365,772 and attorney docket No. 37633.6023D2; the divisional application entitled “METHODS AND SYSTEMS FOR AUTOMATING DEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,” filed on Jul. 7, 2015, having an application number of Ser. No. 14/793,271 and attorney docket No. 8956P023D; and non-provisional utility application entitled “METHODS AND SYSTEMS FOR AUTOMATING DEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,” filed on Mar. 21, 2011, having an application number of Ser. No. 13/052,897 and attorney docket No. 8956P023; and provisional utility application entitled “METHODS AND SYSTEMS FOR AUTOMATING DEPLOYMENT OF APPLICATIONS IN A MULTI-TENANT DATABASE ENVIRONMENT,” filed on May 18, 2010, having an application number of 61/345,977 and attorney docket No. 8956P023Z, the entire contents of which are incorporated herein by reference. 
    
    
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
     TECHNICAL FIELD 
     Embodiments of the invention relate generally to the field of computing, and more particularly, to methods and systems for automating deployment of applications in a multi-tenant database environment. 
     BACKGROUND 
     The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to disclosed embodiments. 
     Conventional large scale farms of machines or machine farms lack sufficient automated architecture that provides functionality to automate provisioning for use of each or any of the respective machines in the farm, including remote installation and upgrading of test applications, Java™ based applications, and the like, as well as general management and maintenance of machines within the farm. Further lacking in conventional mechanisms is functionality to easily run the respective applications hosted by such machines in an automated fashion, without requiring human intervention. 
     Improved mechanisms for automating deployment of applications to multiple machines, such as those operating within a machine farm or a datacenter, is therefore desirable. Solutions to the above mentioned problems and other benefits of Applicants&#39; disclosed embodiments are described in additional detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention are illustrated by way of example, and not by way of limitation, and can be more fully understood with reference to the following detailed description when considered in connection with the figures in which: 
         FIG. 1  depicts an exemplary architectural overview of the environment in which embodiments may operate; 
         FIG. 2  depicts an alternative exemplary architectural overview of the environment in which embodiments may operate; 
         FIG. 3  shows a diagrammatic representation of a system  300  in which embodiments may operate, be installed, integrated, or configured; 
         FIGS. 4A, 4B, and 4C  are flow diagrams illustrating methods for automating deployment of applications in accordance with disclosed embodiments; and 
         FIG. 5  illustrates a diagrammatic representation of a machine in the exemplary form of a computer system, in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Described herein are systems, devices, and methods for automating deployment of applications in a multi-tenant database environment, for example, automating application deployment onto respective machines within a machine farm without requiring human intervention. 
     In a particular embodiment, such mechanisms include managing a plurality of machines operating as a machine farm within a datacenter by executing an agent provisioning script at a control hub within the datacenter instructing the plurality of machines to download and instantiate a lightweight agent; pushing a plurality of URL (Uniform Resource Locator) references from the control hub to the instantiated lightweight agent on each of the plurality of machines specifying one or more applications to be provisioned and one or more dependencies for each of the one or more applications; and loading, via the lightweight agent at each of the plurality of machines, the one or more applications and the one or more dependencies for each of the one or more applications into memory of each respective machine. 
     In the following description, numerous specific details are set forth such as examples of specific systems, languages, components, etc., in order to provide a thorough understanding of the various embodiments. It will be apparent, however, to one skilled in the art that these specific details need not be employed to practice the embodiments disclosed herein. In other instances, well known materials or methods have not been described in detail in order to avoid unnecessarily obscuring the disclosed embodiments. 
     In addition to various hardware components depicted in the figures and described herein, embodiments further include various operations which are described below. The operations described in accordance with such embodiments may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the operations. Alternatively, the operations may be performed by a combination of hardware and software. 
     Embodiments also relate to an apparatus for performing the operations disclosed herein. This apparatus may be specially constructed for the required purposes, or it may be a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, each coupled to a computer system bus. 
     The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear as set forth in the description below. In addition, embodiments of are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the embodiments as described herein. 
     Embodiments may be provided as a computer program product, or software, that may include a machine-readable medium having stored thereon instructions, which may be used to program a computer system (or other electronic devices) to perform a process according to the disclosed embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical), etc. 
     Any of the disclosed embodiments may be used alone or together with one another in any combination. Although various embodiments may have been partially motivated by deficiencies with conventional techniques and approaches, some of which are described or alluded within the specification, the embodiments need not necessarily address or solve any of these deficiencies, but rather, may address only some of the deficiencies, address none of the deficiencies, or be directed toward different deficiencies and problems where are not directly discussed. 
       FIG. 1  depicts an exemplary architectural overview  100  of the environment in which embodiments may operate. Within datacenter  110 , also referred to as a host organization, are a plurality of machines  105 A-G operating as a machine farm  115 . A network  125  connects the machines  105 A-G with a control hub  195  and an application repository  190 . 
     In one embodiment, control hub  195  executes an agent provisioning script (e.g., via agent provisioner  120 ). Agent provisioner  120  or an agent provisioning scrip instructs each of the plurality of machines  105 A-G to download and instantiate a lightweight agent  130 . The lightweight agent  130  is depicted as a deployable  145  within the application repository  190 . In alternative embodiments, the lightweight agent  130  resides within the control hub  195  and is pushed to the respective machines  105 A-G directly from the control hub  195 . 
     Lightweight agent is depicted as having already been downloaded to some of the machines  105 A-G, including machine  105 A, machine  105 B, machine  105 C, and machine  105 D. Machines  105 E,  105 F, and  105 G do not yet have a lightweight agent downloaded or instantiated upon them. 
     Agent provisioner  120  or an agent provisioning scrip additionally pushes a plurality of URL (Uniform Resource Locator) references  170  from the control hub  195  to the instantiated lightweight agent  130  on each of the plurality of machines (e.g., machines  105 A-D having the lightweight agent  130  downloaded thereupon). The URLs  170  specify one or more applications  135  to be provisioned and one or more dependencies  140  for each of the one or more applications  135 . 
     The lightweight agent  130  at each of the plurality of machines loads the one or more applications  135  and the one or more dependencies  140  for each of the one or more applications into memory of each respective machine (e.g., machines  105 A to  105 D as shown in  FIG. 1 ). Loading the one or more applications  135  and the one or more dependencies  140  may constitute the control hub  195  triggering or initiating the loading of the one or more applications  135  and the one or more dependencies  140 , for example, by sending instructions, or manipulating the lightweight agent  130  via commands issued (e.g., through a command shell or other interface) at each of the machines, responsive to which the machines download the necessary applications  135  and dependencies  140  based on the URLs  170 . In an alternative embodiment, once deployed, each lightweight agent  130  operates autonomously to retrieve the necessary applications  135  and dependencies  140  based on the URLs  170  upon receipt of the URLs or responsive to receiving the URLs  170 . 
     Within application repository  190 , two interfaces are depicted, control interface  160  and URL interface  165 . Control interface  160  provides a mechanism over which control hub  195  may interact with application repository  190  as necessary. URL interface  165  provides a mechanism over which the machines  105 A-G in the machine farm  115  may interact with the application repository. More particularly, the machines  105 A-G, upon having received URLs  170  from the control hub  195 , may commence to download the one or more applications  135  to be provisioned and one or more dependencies  140  for each of the one or more applications  135  from the application repository  190 , as specified by the control hub. For example, the machines  105 A-G may communicate with the application repository  190  via HTTP (Hyper Text Transfer Protocol) and/or FTP (File Transfer Protocol), or other available protocols, as specified by the one or more URLs  170 . 
     In one embodiment, the lightweight agent  130  is a small program which functions similar to a bootstrap loader insomuch as it provides each respective machine  150 A-G having the lightweight agent  130  with minimal but sufficient logic to retrieve and load more sophisticated functionality. For example, in development and testing of one embodiment as described herein, the deployable  145  lightweight agent  130  constituted less than 300 total lines of code and required nothing more than a base JDK (Java Development Kit), hence the “lightweight” description. Obviously, a deployable agent to serve such a role may vary in size and sophistication, but still operating in accordance with the disclosed embodiments. 
     In one embodiment, the control hub  195  manages a database  155  specifying relationships between all available applications  135  and all dependencies  140  for the available applications  135 . For example, while multiple dependencies  140  are provided (e.g., classes, objects, linkable programs, etc.), not all dependencies  140  are required for every application  135 . Additionally, while several different and distinct applications  135  are available, different subsets of dependencies  130  will be required depending on which application  135  is being loaded and utilized. These relationships and requirements are tracked by database  155  in accordance with one embodiment. 
     The applications themselves may be test cases or test suites for validating code, testing interfaces, and the like. Some applications may constitute grid based functionality in which each machine  105 A-G operates as a node within a grid that, for example, computes data and reports back results for use in a master application. 
       FIG. 2  depicts an alternative exemplary architectural overview  200  of the environment in which embodiments may operate. The lines connecting various components explicitly to the network  125  have been removed for the sake of clarity, however, the components are obviously still communicatively interconnected via the network  125 . Additionally, while only internal detail of machine  205 B is shown, the other machines  205 A and  205 C operate in an identical fashion. In some embodiments, the numbers and scale of deployed machines may be significant, for example, well into the hundreds of machines controllable via a single control hub.  FIG. 2  depicts in additional detail the manner in which machines (e.g.,  105 A-D) of  FIG. 1  and machines  205 A-C here, may be provisioned in accordance with disclosed embodiments. 
     For example, in accordance with one embodiment, the agent provisioner  120  or agent provisioning script instructs each of the plurality of machines (e.g.,  205 A,  205 B, and  205 C) to download and instantiate the lightweight agent  130 . In such an embodiment, instructing the plurality of machines (e.g.,  205 A,  205 B, and  205 C) to download and instantiate the lightweight agent  130  includes the agent provisioner  120  or agent provisioning script to: access a list  295  specifying a location name for each of the plurality of machines  205 A-C to be provisioned with the lightweight agent. The list  295  may reside locally within control hub  195  or, in alternative embodiments, may reside within and be accessed from database  155 . List  295  may include a listing of one or more data including: host names, host IP addresses (Internet Protocol addresses), MAC addresses (Media Access Control addresses), passwords, encryption keys, zoning, hardware type or hardware specification data, etc. Database  155  further includes a table structure  290  specifying the relationships between all available applications  135  and all dependencies  140  for the available applications  135 , which may be utilized by the control hub  195  in determining what applications and dependencies to provision to the machines  205 A-C (e.g., by pushing URLs  170  corresponding to the determined applications  135  and all dependencies  140 ). The doubled headed line between agent provisioner  120  and database  155  depicts the interactions by which the agent provisioner retrieves information from database table structure  290  or list  295 , as necessary. 
     In such an embodiment, instructing the plurality of machines  205 A-C to download and instantiate the lightweight agent  130  additionally includes, for each of the plurality of machines  205 A-C specified by the list  295 : a) logging in to a command shell  285  (e.g., a Command Line Interface (CLI) or other remotely accessible interface) on the specified machine (e.g., one of  205 A,  205 B, and  205 C) from the control hub  195 ; b) instructing, by issuing commands to the command shell  285 , the specified machine (e.g., one of  205 A,  205 B, and  205 C) to download the lightweight agent  130  from the control hub  195 ; and c) instructing, by issuing the commands to the command shell, the specified machine (e.g., one of  205 A,  205 B, and  205 C) to start the lightweight agent  130 . In alternative embodiments, the control hub  195  may access the command shell  285  and instruct each respective machine to download the lightweight agent  130  from the application repository  190 . The straight double headed line between agent provisioner  120  and the command shell  285  of machine  205 B represents the interaction and connectivity between the two elements in fulfillment of the above communication of commands and triggering of the described events. 
     In one embodiment, each of the plurality of machines  205 A-C pulls the lightweight agent  130  from the control hub  195  responsive to the agent provisioning script or the agent provisioner  120 . In such an embodiment, each of the plurality of machines  205 A-C pulls the one or more applications  135  and the one or more dependencies  140  for each of the one or more applications  135  from a central application repository  190 . Therefore, in accordance with the described embodiments, control hub  195  may cause the machines  205 A-C to pull the lightweight agent  130 , or the control hub  195  may directly push the lightweight agent  130  to each of the machines  205 A-C (e.g., via remote copy or other such mechanisms capable of pushing data and/or files onto another machine). 
     In accordance with one embodiment, the control hub  195  and the central application repository  190  each reside on physically separate and distinct computer servers. In accordance with one embodiment, each of the plurality of machines  205 A-C in the machine farm  115  are physically separate and distinct computer servers from the control hub  195  and from the central application repository  190 . In such an embodiment, each of the plurality of machines  205 A-C in the machine farm  115  are physically separate and distinct computer servers from each other. In alternative embodiments, at least a portion of the machines  205 A-C are distinct computing blades within a blade server or blade machine or distinct nodes within a computing grid of nodes. In alternative embodiments, at least a portion of the machines  205 A-C are distinct virtual machines co-located upon a single physical computing device, but are virtualized to appear as independent and physically distinct computing devices. 
     In one embodiment, each of the physically separate and distinct computer servers (e.g., machines  205 A-C) and the control hub  195  are communicatively interfaced through a high speed network (e.g.,  125 ) of the datacenter  110 . 
     In accordance with one embodiment, the lightweight agent  130  is downloaded and instantiated within memory  201  of each of the plurality of respective machines  205 A-C. In such an embodiment, execution of the lightweight agent  130  is isolated to the memory  201  of each of the respective machines  205 A-C. In one embodiment, the one or more applications  135  and the one or more dependencies  140  for each of the one or more applications reside only within the memory  201  of the respective plurality of machines. In one embodiment, each of the lightweight agents  130 , the one or more applications  135 , and the one or more dependencies  140  for each of the one or more applications  135 , do not access or reference hard disk drive storage on any of the plurality of respective machines  205 A-C having the lightweight agent  130  downloaded and instantiated thereon. Stated differently, regardless of whether any one of the respective machines  205 A-C is provisioned with a hard disk drive, the lightweight agent  130  operates memory resident and does not rely upon, or make use of, the hard disk drive. In accordance with other embodiments, the applications  135  and dependencies  140  operate in the same manner. In some embodiments, the machines  205 A-C are headless, keyboardless, and diskless, but include at least a CPU and memory upon which to execute and perform instructions (e.g., “bare metal” machines). 
     Further depicted within  FIG. 2  are elements  250 ,  255 ,  260 , and  265 . Element  250  represents the lightweight agent  130  being provisioned to machine  205 B in accordance with one embodiment. In such an embodiment, the lightweight agent  130  is pushed to machine  205 B from control hub  195 . Element  255  represents the plurality of URLs  170  which are pushed to machine  205 B by the control hub  195  enabling machine  205 B, via its lightweight agent  130 , to pull the appropriate applications  135  and dependencies  140  from the application repository. Element  260  represents the lightweight agent  130  pulling one or more applications  135  from the application repository  190  as specified by the control hub  195  (e.g., based on the plurality of URLs  170  pushed to the machine). And element  265  represents the lightweight agent  130  pulling one or more application dependencies  140  from the application repository  190  as specified by the control hub  195  in support of the pulled applications  135 . 
     In accordance with one embodiment, the control hub  195  manages an upgrade procedure for the plurality of machines  205 A-C. In such an embodiment, the upgrade procedure includes the control hub issuing a graceful interrupt to each of the plurality of machines  205 A-C, in which the graceful interrupt permits each respective machine to complete currently executing work, for example, each of the plurality of respective machines  205 A-C will allow the one or more applications  135  currently executing work to complete (e.g., without early termination) responsive to receiving a graceful interrupt. In one embodiment, the upgrade procedure includes each of the plurality of respective machines to: stop accepting work instructions responsive to the graceful interrupt issued by the control hub; to respond to the control hub with a notification indicating the respective machine is ready to receive instructions from the control hub; and to receive upgrade instructions from the control hub  195 . In one embodiment, the upgrade procedure operates asynchronously, such that various operations undertaken by each of the plurality of respective machines  205 A-C will begin and end on their own schedules and time tables. For example, one machine may be continuing execution of its current work, while another machine receives upgrade instructions from the control hub  195 . 
     In one embodiment, the upgrade procedure further includes the control hub  195 , responsive to receiving the notification from each respective machine  205 , performs an unloading operation of a test class installation (e.g., an application  135 ) from the machine&#39;s memory, via the machine&#39;s lightweight agent (e.g., the control hub  195  instructs lightweight agent  130  to unload specified test class or other installed application  135 ). In such an embodiment, the upgrade procedure further includes the control hub  195  to perform an unloading operation of all dependencies  140  associated with the test class installation (e.g., application dependencies  140 ) from the machine&#39;s memory  201  as specified by the control hub  195  (e.g., where the operation is implemented via the machine&#39;s lightweight agent). In such an embodiment, the upgrade procedure further includes the control hub  195  to cause or instruct the machine&#39;s lightweight agent to download and install a new application  135  from an application repository  190  to the machine&#39;s memory  201  as specified by the control hub  195  and download and install, via the machine&#39;s lightweight agent, all dependencies  140  for the new application  135  from the application repository  190  to the machine&#39;s memory  201  as specified by the control hub  195 . In such an embodiment, the upgrade procedure further includes the control hub  195  to start, via the machine&#39;s lightweight agent, the new application  135  within the respective machine (e.g., one of  205 A-C as depicted at  FIG. 2 , or one of  105 A-G as depicted by  FIG. 1 ). 
     In accordance with one embodiment, the lightweight agent  130  implements a container  203  for managing class objects within each of the respective machines  205 A-C. In such an embodiment, loading the one or more applications  135  into the memory  201  of the respective plurality of machines  205 A-C includes: a) allocating an exclusive memory space  202  for each of the one or more applications  135  within the memory  201  of the respective machine (e.g., one of  205 A-C); b) uniquely associating a dynamically generated URL class loader  231 A and  231 B for each of the one or more applications  135  within the exclusive memory space  202  allocated to the one or more applications  135 ; and loading, via the uniquely associated URL class loader  231 A and  231 B, each respective application  135  into the exclusive memory space  202  and each of the one or more dependencies into the exclusive memory space  202  allocated to the respective application  135  based on the plurality of URL references  170  pushed to the lightweight agent  130 . 
     In one embodiment, the container  203  for managing class objects implemented via the lightweight agent includes a managed bean server. In one embodiment, the lightweight agent  130  is implemented as a JVM (Java Virtual Machine) which includes the managed bean server (e.g., MBeanServer). In one embodiment, the lightweight agent  130  further includes a Java Remote Method Invocation Application Programming Interface (e.g., a Java RMI), or a Java based or Java compatible Application Programming Interface (API) that performs the object-oriented equivalent of Remote Procedure Calls (RPC), or another Remote Method Invocation (RMI) mechanism. The lightweight agent  130  may further include an RMI registry and a custom security manager. In such embodiments, the lightweight agent  130  acts as a remote agent when communicating with the control hub  195 . The lightweight agent  130  installed onto each of the machines  205 A-C in the server farm or machine farm  115  exposes Transmission Control Protocol (TCP) ports that are used to send application control requests. The methods for application control include, for example, load, stop, start, and unload. Additionally, within the applications  135  themselves, additional methods may be arbitrarily defined in accordance with the disclosed embodiments. Such additional methods are available to be executed remotely once the application  135  has been loaded into the lightweight agent&#39;s  130  MBeanServer. 
     In one embodiment, the MBeanServer is responsible for listening for external commands and is additionally responsible for staying alive within each of the machines  205 A-C (e.g., responsible for keeping itself and the communication capabilities of the lightweight agent  130  alive so that each machine remains responsive to remote commands, without becoming a dead node, requiring human interaction, such as a hard reboot). In one embodiment, the managed bean server provides a container  203  for plugging in applications  135 . 
     In one embodiment, the managed bean server exposes standard interfaces to the control hub  195 . For example, the standard interfaces exposed may include “start” and “interrupt.” In some embodiments, a graceful interrupt and a hard interrupt may be exposed, or defined and selectable by the issuing entity (e.g., the control hub  195 ). 
     In one embodiment, the managed bean server additionally provides query and self discovery mechanisms which dynamically discover/identify/find all non-standard and arbitrarily defined interfaces within provisioned applications  135 . In such an embodiment, other than implementing standard stop, interrupt, stop type methods, custom interfaces defined by code authors are also discoverable and will be exposed by the managed bean server upon discovery, without requiring further intervention. Such exposed interfaces, whether standard or arbitrarily defined, are thus accessible to and accessible via the control hub  195  which may issue commands, instructions, and interactions to the various exposed methods to launch events, tests, and so forth. Such exposed methods are therefore also manipulatable via administration consoles and interfaces provided thorough the control hub  195  as will be described in additional detail below. 
     In one embodiment, at least a portion of the machines  205 A-C in the machine farm  115  are provisioned with a JMX (Java™ Management Extension) based or JMX compatible lightweight agent  130  which receives remote instructions from a control hub  195 . In one embodiment, when an application  135  is loaded and an operation is executed remotely, all processing happens within a JVM of a JMX based or JMX compatible lightweight agent  130 . JMX based lightweight agents  130  may automatically pull down application  135  code and dependency  140  Java Archives (JARs) from a application repository  190 , and subsequently run each application  135  represented within the application  135  code and dependency  140  JARs in a separate classloader but within the same JVM (Java™ Virtual Machine) based or JVM compatible interpreter. Such a mechanism yields complete control over the deployment and lifecycle management of deployed Java based or Java compatible applications in a large scale distributed system, all from a single remote controller application accessible from, for example, control hub  195 . Such an approach may simplify the role of a system administrator, and thus reduce cost and complexity and the risk of human error on behalf of an Enterprise (e.g., a host organization or a business Enterprises and an associated computing environment that supports the business objectives of the host organization/business Enterprise through computing systems in, for example, a datacenter  110  or machine farm  115 ). 
     In one embodiment, a JMX based or JMX compatible lightweight agent  130  loads managed applications  135  and dependent libraries and/or application dependencies  140  from an application repository  190  via URL mappings as set forth by one or more of the plurality of URLs  170  pushed to the various machines ( 205 A-C. In such an embodiment, relationships between the applications  135  and the dependent libraries and/or application dependencies  140  are managed within a database schema accessible to control hub  195  or via a relationships table structure  290  as described above. The database schema and/or relationships table structure  290  may reside within control hub  195  as an alternative to being accessible from database  155  as described above. In one embodiment, the applications  135  themselves are packaged as JAR files, and as such, do not include the dependent libraries and/or application dependencies  140  because all dependencies  140  are handled within classloaders  231 A and  231 B which are created dynamically within the JMX based or JMX compatible lightweight agent&#39;s  130  MBeanServer. When dependent libraries and/or application dependencies  140  are needed by the applications  135 , they are populated in the classloader  231 A or  231 B assigned to the loaded application  135  operating within an isolated memory space (e.g., exclusive memory space  202 ). 
     Classloader isolation is supported in accordance with certain embodiments. Classloader isolation facilitates the hosting of multiple applications  135  within a single JVM, where each application  135  is given it&#39;s own dynamically generated URL Classloader  231 A or  231 B. By isolating each classloader  231 A or  231 B, dependencies  140  between an application  135  and it&#39;s corresponding dependent libraries and/or application dependencies  140  are strictly maintained while also creating a process space dedicated to each application within the agent&#39;s JVM. For example, exclusive memory space  202  is allocated to the one or more applications  135  within the memory  201  of the respective machine (e.g., one of  205 A-C). In certain embodiments, the machine  205 A-C and its JMX based or JMX compatible lightweight agent  130  makes exclusive use of URL Classloaders  231 A and  231 B, which in turn assures that there are no dependencies  140  on any local file system or hard disk drive within the machine  205 A-C upon which the lightweight agent  130 . 
     Embodiments which implement URL class loaders  231 A and  231 B and managed bean servers as described above additionally make applications pluggable, and are able to better leverage a highspeed network  125  available within the datacenter  110  for downloading and provisioning applications  135  and dependencies  140  to the machine farm  115 . 
     In accordance with one embodiment, a non-transitory computer readable storage medium has instructions stored thereon. In such an embodiment, the instructions, when executed by control hub  195  having a processor and memory therein, cause the control hub  195  to perform operations, perform a method, or carry out instructions, for managing a plurality of machines  205 A-C within a datacenter  110  by implementing operations and functionality as described in accordance with the various embodiments set forth above. 
     For example, in one embodiment, instructions stored upon a non-transitory computer readable storage medium causes a control hub  195  to perform operations including instructing each of a plurality of machines  205 A-C to download and instantiate a lightweight agent  130  (e.g., either JMX based, JMX compatible, or non-JMX based). In such an embodiment, operations further include pushing a plurality of URL references  170  from the control hub  195  to the instantiated lightweight agent  130  on each of the plurality of machines  205 A-C, in which the plurality of URL references  170  specify one or more applications  135  to be provisioned and one or more dependencies  140  for each of the one or more applications  135  also to be provisioned in support of the applications  135 . In such an embodiment, operations further include instructing the lightweight agent  130  at each of the plurality of machines  205 A-C to load the one or more applications  135  and the one or more dependencies  140  for each of the one or more applications  135  into memory  201  of the respective one of the plurality of machines  205 A-C. 
     In accordance with one embodiment, a remote control Graphical User Interface (GUI) is implemented in which each of the plurality of deployed lightweight agents  130  are individually graphically displayed via the GUI and individually controllable via a JMX remote control client, implemented as a servlet in the control hub  195 . In such an embodiment, connections may be established to each of the plurality of deployed lightweight agents  130  by specifying both the JMX and RMI URL&#39;s to create a connection string of the form of: “service:jmx:rmi://&lt;HOST_NAME&gt;:&lt;JMX_PORT&gt;/jndi/rmi://&lt;HOST_NAME&gt;:&lt;RMI_PORT&gt;/server.” 
     Upon establishing a connection to one of the lightweight agents  130 , two separate MBeans are created. A first for the application  135  that is being loaded and a second for the classloader  231 A or  231 B that the loaded application will use (e.g., be uniquely associated with and under the control of). When the application MBean is created, an application-specific classloader MBean is provided to a createMBean method, associating the two MBeans and allowing the application  135  to load its main and dependent libraries and/or application dependencies  140  in an isolated manner, within the exclusive memory space  202  established for the one or more applications  135  within the memory  201  of the respective machine (e.g., one of  205 A-C). 
     A jconsole connection may be established with any of the one or more running lightweight agents  130  via the GUI. JConsole is a graphical monitoring tool to monitor Java Virtual Machines (JVM) and java based or java compatible applications on both local and remote machines, such as the remote applications  135  executing on the machines  205 A-C which are remote from the control hub  195 . 
     In one embodiment, the upgrade procedure described above is implemented via an external client application which uses upgrade information inserted into the control hub  195  to perform automatic upgrades of JMX based or JMX compatible applications  135  executing within JMX based or JMX compatible lightweight agents  130 . In one embodiment, the external client application waits until a targeted application  135  provisioned to one of the plurality of machines  205 A-C is marked as offline via the control hub  195 . In such an embodiment, the external client application then proceeds to destroy the classloader  231 A and  231 B and unload the application  135  MBean from the JMX based or JMX compatible lightweight agent  130 . The lightweight agents  130  disables URLConnection caching to prevent stale classes (e.g., classes embodying applications  135  and dependencies  140 ) from being used once an upgrade is performed. In embodiments that make exclusive use of URLClassloaders (e.g., MLetClassloaders), an upgrade or reload of an application  135  destroys all references to the application  135  and its associated classloader  231 A and  231 B. In such an embodiment, the external client application then reloads the specified application  135  and recreates the classloader  231 A and  231 B MBean to make the application  135  available for execution and management (e.g., makes it deployable  145 ). MLetClassloaders are a class that represents the class loader that the m-let service uses to load classes and resources. The term “Mlet” or “M-let” refers to a “Management applet,” which is a utility MBean to load, instantiate and register MBeans in the MBeanServer. 
     In one embodiment, a GUI additionally provides an administration console to select the machines  205 A-C within the machine farm  115 , select the application(s)  135  executing within the machine farm  115 , and/or select the associated remote method(s) to invoke which are exposed to the control hub  195  and made accessible and viewable via the GUI of the control hub&#39;s  195  administration console, in accordance with the above embodiments. For example, such an administration console permits system administrators to perform remote operations on applications  135  and to load/unload the applications  135  from deployed lightweight agents  130 . The administration console again makes use of the servlet that is exposed on the control hub  195 . Such an administration console further permits an administrator to perform operations on multiple lightweight agents  130  deployed within the machine farm  115  concurrently. For example, an administrator may start a specific application  135  on several different machines  205 A-C via the administration console which permits the administrator to select the machines  205 A-C, select the application(s)  135 , and select the associated remote method(s) to invoke, in accordance with the disclosed embodiments. 
       FIG. 3  shows a diagrammatic representation of a system  300  in which embodiments may operate, be installed, integrated, or configured. 
     In one embodiment, system  300  includes a memory  395  and a processor or processors  390 . For example, memory  395  may store instructions to be executed and processor(s)  390  may execute such instructions. System  300  includes bus  385  to transfer transactions and data within system  300  such as transactions between hardware based control hub  101  and database  355  or the data store  350 . System  300  further includes database  355  which may store a relationship table structure specifying the relationships between available applications and dependencies available from an application repository, and which control hub  301  may provision to remote machines (e.g.,  105 A-C as set forth in  FIG. 1 ). Database  355  may additionally store a list of remote machines and location information for such machines (e.g., host names, IP addresses, etc.). Alternatively, such a list may be stored within data store  350  (e.g., list  365 ). 
     System  300  includes data store  350  to store data and information. Data store  350  stores a copy of deployable lightweight agent  330  in accordance with one embodiment. 
     Distinct within system  300  is hardware based control hub  301  which includes Remote Method Invocation (RMI) Agent  305 , Agent Provisioner  310 , and Machine List Manager  315 . In accordance with one embodiment, Remote Method Invocation (RMI) Agent  305  enables hardware based control hub  301  to remotely communicate with, remotely trigger, remotely initiate, and remotely instruct lightweight agents  330  deployed within machines in a machine farm to perform actions and events as specified by the hardware based control hub  301 . In such an embodiment, Agent Provisioner  310  deploys the deployable lightweight agent  330  to machines within a machine farm and Machine List Manager  315  provides a listing of the machines within the machine farm upon which the deployable lightweight agent  330  may be deployed and controlled and a location, location name, IP address, or other appropriate information for the machines in the machine farm so that the deployable lightweight agent  330  may be deployed by the hardware based control hub  301 . 
       FIGS. 4A, 4B, and 4C  are flow diagrams illustrating methods ( 400 ,  401 , and  402 ) for automating deployment of applications in accordance with disclosed embodiments. Method  400  depicts operations for managing a plurality of machines operating as a machine farm in a datacenter. Method  400  operates within a control hub. Method  401  depicts operations for receiving automated deployments and application upgrades. Method  401  operates at one of a plurality of machines in a machine farm. Method  402  depicts operations for invoking methods within one or more machines in a machine farm from a control hub. Method  402  operates in conjunction with both a control hub and at least one machine within a machine farm. Methods  400 ,  401 , and  402  may be performed by processing logic that may include hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions run on a processing device to perform various operations such as deploying, provisioning, issuing remote commands and control, etc.), or a combination thereof. In one embodiment, methods  400 ,  401 , and  402  are performed by hardware logic, such as the hardware based control hub depicted at element  301  of  FIG. 3  or by a machine within a machine farm such as those depicted at elements  105 A-G of  FIGS. 1 and 205A -C of  FIG. 2 . Some of the blocks and/or operations listed below are optional in accordance with certain embodiments. The numbering of the blocks presented is for the sake of clarity and is not intended to prescribe an order of operations in which the various blocks must occur. 
     Method  400  of  FIG. 4A  begins with processing logic executing an agent provisioning script at a control hub (block  405 ). At block  410 , processing logic in a control hub accesses a list specifying a location name for each of a plurality of machines to be provisioned with a lightweight agent. 
     At block  415 , processing logic in a control hub logs into a command shell on each specified machine from the control hub. The control hub may continue to execute instructions, or deploy a provisioning script which, when executed on a target machine, performs operations specified by the control hub. At block  420 , processing logic instructs, via commands to a remote command shell, each specified machine to download the lightweight agent from the control hub. Alternatively, the control hub may deploy and execute the provisioning script, thus causing the target machine to pull or download the lightweight agent from the network (e.g.,  125 ). 
     At block  425 , processing logic instructs, via commands to the remote command shell, each specified machine to start the lightweight agent previously downloaded. Alternatively, the provisioning script may instantiate the lightweight agent subsequent to its pull or download operations. 
     At block  430 , processing logic on the control hub pushes a plurality of URL (Uniform Resource Locator) references from the control hub to the instantiated lightweight agent on each of the plurality of machines specifying applications and dependencies to be provisioned. 
     At block  435 , processing logic on the control hub instructs each of the plurality of machines to load, via the lightweight agent, applications and dependencies into a memory of each respective machine. 
     At block  440 , processing logic on the control hub instantiates/triggers/initiates an upgrade procedure for the plurality of machines or a portion thereof. At block  445 , processing logic on the control hub issues a graceful interrupt to each of the plurality of machines in furtherance of the upgrade procedure, or to the portion of machines for which the upgrade procedure is instantiated/triggered/initiated. At block  450 , processing logic on the control hub waits for and receives a notification from each of the plurality of machines indicating the respective machine is ready to receive instructions from the control hub. The notifications from the respective machines are received asynchronously, as each respective machine reaches a state at which it issues such notifications. 
     At block  455 , processing logic on the control hub issues upgrade instructions to each of the plurality of machines (in an asynchronous manner responsive to each of the received notifications), including unloading installed applications and dependencies, downloading and installing new applications and dependencies, and starting the new application(s). 
     Method  401  of  FIG. 4B  begins with processing logic executing one of any of a plurality of machines within a machine farm, where the processing logic pulls a lightweight agent from a control hub responsive to remote instructions from the control hub. Alternatively, the machine receives a provisioning script from the control hub, executes the provisioning script, and pulls the lightweight agent from the control hub based on instructions within the provisioning script (block  460 ). 
     At block  462 , processing logic in the machine implements a container for managing class objects. 
     At block  464 , processing logic in the machine receives a plurality of URL references specifying applications and dependencies to be downloaded. At block  466 , processing logic in the machine downloads the applications and dependencies via the URL references. 
     At block  470 , processing logic in the machine uniquely associates a dynamically generated URL class loader with each application. At block  472 , processing logic in the machine loads, via the uniquely associated URL class loader, each respective application and its dependencies into the exclusive memory space allocated to the applications. 
     At block  474 , processing logic in the machine responds to an upgrade procedure initiated by the control hub by first receiving a graceful interrupt from the control hub. At block  476 , processing logic in the machine allows currently executing work of the loaded application(s) to complete in view of the graceful interrupt (e.g., the interrupt is not a hard interrupt demanding immediate termination). At block  478 , processing logic in the machine stops accepting work instructions responsive to the graceful interrupt. 
     At block  480 , processing logic in the machine responds to the control hub with a notification when the machine is ready to receive further instructions from the control hub (e.g., indicating to the control hub that it is now ready to proceed with further instructions, other instructions, or the upgrade procedure initiated by the control hub). The actual notification sent may be only a “ready” notice or a message indicating the machine is at a state capable of receiving further instruction. 
     At block  482 , processing logic in the machine receives upgrade instructions from the control hub, including instructions to unload all test classes and applications and associated dependencies, to download and install a new application and dependencies, and to start the new application (e.g., by either instructing the lightweight agent to start the new application, or by restarting the lightweight agent thus causing it to restart its known applications upon startup). 
     Method  402  of  FIG. 4C  begins with processing logic exposing, from a machine in a machine farm, one or more standard methods including at least start, stop, and interrupt (block  485 ). 
     At block  486 , processing logic searches, within the machine in the machine farm, one or more applications and dependencies loaded at the machine for arbitrarily defined non-standard methods associated with the one or more applications and dependencies and at block  487 , processing logic exposes, from the machine in the machine farm, the arbitrarily defined non-standard methods discovered by the search. 
     At block  488 , processing logic at an administration console of a control hub lists a plurality of machines in the machine farm. For example, the administration console may list all, active, a zone, a subset, or a specified type or class of machines, etc. 
     At block  489 , processing logic lists at the administration console, all invokable methods for each machine listed by the administration console, including both standard methods exposed by each respective machine and arbitrarily defined non-standard methods exposed by each respective machine. 
     At block  490 , processing logic at the administration console of the control hub receives a selection specifying one or more standard and/or non-standard methods to invoke at one or machines listed in the machine farm. 
     At block  491 , processing logic at the control hub generates one Remote Method Invocation (RMI) connection string for every specified standard and/or non-standard method to invoke at each specified machine upon which the specified standard and/or non-standard method is to be invoked. For example, if two machines are selected via the administration console and two invokable methods are selected at each, four RMI strings would be generated in accordance with such an embodiment. 
     At block  492 , processing logic at the control hub issues the generated RMI connection strings, for example, invoking them via a network connecting the control hub with the machines in the machine farm. 
     At block  493 , processing logic at each machine in the machine farm identified by at least one RMI connection string receives instructions to invoke one or more standard and/or non-standard methods and at block  494 , processing logic at each respective machine identified by at least one RMI connection string issued from the control hub invokes the one or more standard and/or non-standard methods in accordance with the instructions received by the corresponding machine. 
       FIG. 5  illustrates a diagrammatic representation of a machine  500  in the exemplary form of a computer system, in accordance with one embodiment, within which a set of instructions, for causing the machine  500  to perform any one or more of the methodologies discussed herein, may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. The machine may operate in the capacity of a server or a client machine in a client-server network environment, as a peer machine in a peer-to-peer (or distributed) network environment, as a server or series of servers within an on-demand service environment, as a blade within a blade server, as a node within a computing grid, or as a physically separate and distinct machine within a machine farm of a datacenter. Certain embodiments of the machine may be in the form of a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, computing system, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Additionally, while the embodiment set forth at  FIG. 5  depicts various elements, each of which are described below, not all elements of the machine are required in accordance with certain embodiments. For example, some embodiments make use of a “bare metal” machine deployed within a machine farm, in which the machine operates headless (e.g., without a display device such as user interface  510 ) and keyboardless (e.g., without alphanumeric input device  512  and cursor control device  514 ). In some embodiments, machines within a machine farm operate without use of a hard disk drive. However, in all embodiments, machines deployed within a machine farm include at least a CPU (e.g., processor  502 ) and memory (e.g., main memory  504 ), but the contents of such memory may vary from that which is depicted at  FIG. 5 . Alternative combinations of elements depicted are utilized in machines which embody a control hub, a database, and/or an application server as described in the embodiments set forth above. 
     The exemplary computer system  500  includes a processor  502 , a main memory  504  (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc., static memory such as flash memory, static random access memory (SRAM), volatile but high-data rate RAM, etc.), and a secondary memory  518  (e.g., a persistent storage device including hard disk drives and a persistent database and/or a multi-tenant database implementation), which communicate with each other via a bus  530 . Main memory  504  includes a list of machines (e.g., names and location information for machines in a machine farm)  524  and a deployable lightweight agent  523  which is pushed to communicatively interfaced machines in a machine farm. Main memory  504  and its sub-elements (e.g.  523  and  524 ) are operable in conjunction with processing logic  526  and processor  502  to perform the methodologies discussed herein. 
     Processor  502  represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processor  502  may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processor  502  may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. Processor  502  is configured to execute the processing logic  526  for performing the operations and functionality which is discussed herein. 
     The computer system  500  may further include a network interface card  508 . The computer system  500  also may include a user interface  510  (such as a video display unit, a liquid crystal display (LCD), or a cathode ray tube (CRT)), an alphanumeric input device  512  (e.g., a keyboard), a cursor control device  514  (e.g., a mouse), and a signal generation device  516  (e.g., an integrated speaker). The computer system  500  may further include peripheral device  536  (e.g., wireless or wired communication devices, memory devices, storage devices, audio processing devices, video processing devices, etc.). The computer system  500  may further include a Hardware based control hub  534  to manage a plurality of machines operating as a machine farm within a datacenter in accordance with the described embodiments. 
     The secondary memory  518  may include a non-transitory machine-readable or computer readable storage medium  531  on which is stored one or more sets of instructions (e.g., software  522 ) embodying any one or more of the methodologies or functions described herein. The software  522  may also reside, completely or at least partially, within the main memory  504  and/or within the processor  502  during execution thereof by the computer system  500 , the main memory  504  and the processor  502  also constituting machine-readable storage media. The software  522  may further be transmitted or received over a network  520  via the network interface card  508 . 
     While the subject matter disclosed herein has been described by way of example and in terms of the specific embodiments, it is to be understood that the claimed embodiments are not limited to the explicitly enumerated embodiments disclosed. To the contrary, the disclosure is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosed subject matter is therefore to be determined in reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.