Patent Publication Number: US-2022237152-A1

Title: Determining available remote storages in a network to use to replicate a file based on a geographical requirement with respect to the file

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a computer program product, system, and method for determining available remote storages in a network to use to replicate a file based on a geographical requirement with respect the file. 
     2. Description of the Related Art 
     An Enterprise Content Management (ECM) system manages the storage, preservation, archival, replication, synchronization, and life cycle of documents according to organizational processes. An ECM system may manage multiple replicas of a document in different locations for the purposes of availability, disaster recovery, and performance. These replicas may be distributed across multiple geographies in order to increase the resilience of the system to failure. In fact, a system with strong disaster recovery requirements may enforce such remote geographical distributions as a requirement, for example requiring that replicas of a document be stored in at least two different locations, such as different nations, states, etc. 
     There is a need in the art for improved techniques to replicate documents across different geographical locations and boundaries according to enterprise needs. 
     SUMMARY 
     A first embodiment comprises a computer program product, system, and method for replicating a file to a remote storage. Provided are a computer program product, system, and method for determining available remote storages in a network to use to replicate a file based on a geographical requirement with respect the file. A determination is made as whether available remote storages satisfy constraints associated with a document class of the file. The constraints include a geographical location at which to replicate the file and a minimum number of replications to create for the file. At least one remote storage of the available remote storages is selected that satisfies the constraints to store at least one copy of the file. The file is replicated to the selected at least one remote storage 
     Described embodiments provide constraints to replicating a file including a geographical location to address restrictions on where a file may be replicated based on a document class of the file, such as if the file has Personally Identifiable Information (PII) or Sensitive Personal information (SRI). These geographical location may be imposed by national law to prevent transfer of certain sensitive file data beyond a national boundary. Described embodiments provide improvements to replication technologies to automatically manage the replication to satisfy the geographic location and at the same time also satisfy replication requirements that specify a minimum number of replications that must be made within the geographical locations dictated by the geographical restrictions. 
     In a second embodiment, the first embodiment may further include determining whether the available remote storages satisfy the constraints determines whether one of the available remote storages satisfies a location requirement with respect to where the file was created 
     With the second embodiment, the geographical location requirement may consider the location of where the file was created to determine the geographical restriction. This ensures that files are not moved to a restricted geographical location with respect to where they were created, because the geographical location may restrict files having sensitive data, such as PII and SPI, from being transferred beyond the location from where they were created, such as a national or jurisdictional boundary. 
     In a third embodiment, the second embodiment may further include that the determining whether the available remote storages satisfy the constraints comprises determining whether there are the minimum number of replications within the geographical location of where the file was created. 
     With the third embodiment, the determination is made of multiple remote storages that comprise the minimum number of remote storages to store the minimum number of copies of the file to satisfy the replication requirement such that these minimum number of remote storages must also satisfy the geographical location requirement that the remote storages are within the geographical location of where the file was created. With this third embodiment, replication complies with any geographic location restrictions imposed by legal authorities to prevent transfer of the file beyond a location requirement and at the same time the file is assured to perform a minimum number of replications so the file is sufficiently protected at different locations. 
     In a fourth embodiment, the first embodiment may further include determining whether there is at least one available remote storage that satisfies the geographical location in response to determining that the available remote storages do not satisfy the constraints. The file is replicated to the at least one available remote storage that satisfies the geographical location in response to determining that the available remote storages do not satisfy the constraints. 
     With the fourth embodiment, if there are not the minimum number of remote storages satisfying the geographical location requirement, then the file is replicated to the available remote storages that satisfy the geographical location requirement to allow for some replication even if the replication requirement is not satisfied. This provides for some level of replication to be performed to provide some level of protection of the file even if the minimum number of replications cannot be satisfied. 
     In a fifth embodiment, the fourth embodiment may further include that in response to determining that there is the at least one available remote storage that satisfies the geographical location when the constraints are not satisfied, determining a remaining number of replications comprising the minimum number of replications minus a number of the at least one available remote storage to which the file is replicated. The file is indicated in a replication queue to replicate the file to at least one remote storage that becomes available that satisfies the geographical location until the remaining number of replications of the file is performed. 
     With the fifth embodiment, if there are not the minimum number of available remote storages that satisfy the geographical location requirement, then a remaining number of replications is determined of the replications that could not complete. Indication is made in a replication queue of these remaining number of replications to perform for the file so as remote storages that satisfy the geographic requirement become available, the queued replications can be performed until the minimum number of replications are performed to satisfy the replication requirement. This allows for as much replication as possible to be performed that satisfies any geographical requirements, which may comprise legal requirements that must be met, and then allow for the remaining replications to be performed as remote storages become available that satisfies the geographical requirements. 
     In a sixth embodiment, the fifth embodiment may further include initiating a configuration of a remote storage that satisfies the geographical location to make available to replicate the file indicated in the replication queue. 
     With the sixth embodiment, if there are not the minimum number of available remote storages, then remote storages may be automatically configured to satisfy the geographical location requirement so these configured remote storages may be used to replicate for the queued remaining number of replications in the replication queue. In this way, replication is made to the maximum sites possible that satisfy the geographical location and additional remote storages are automatically configured that satisfy the geographical location requirement to allow the replication requirement to be completed without user involvement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an embodiment of a network storage environment. 
         FIG. 2  illustrates an embodiment of file metadata. 
         FIG. 3  illustrates an embodiment of storage metadata. 
         FIG. 4  illustrates an embodiment of constraints. 
         FIG. 5  illustrates an embodiment of a replication queue entry. 
         FIGS. 6 a  and 6 b    illustrate an embodiment of operations to replicate a file based on geographical and replication requirements. 
         FIG. 7  illustrates an embodiment of operations to utilize a configured remote storage to complete queued file replications. 
         FIG. 8  illustrates a computing environment in which the components of  FIG. 1  may be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     When replicating documents in an enterprise system, different regulations and laws may apply with respect to handling data such as Personally Identifiable Information (PII) or Sensitive Personal Information (SPI). While some documents can be replicated anywhere, other documents may not be allowed to be legally stored in or exported to another geography, such as another country. Thus, there is a need to limit the available locations of document replicas to meet security, regulatory, and company guidelines. 
     Described embodiments provide improvements to file replication technologies to automatically manage the replication of data across geographical locations to manage geographic requirements, such as restrictions or limits on where a file may be replicated. Whenever a document is uploaded or updated in a system, described embodiments apply constraints including geographical and replication requirements, where a geographical requirement provides a requirement with respect to a geographical location at which to replicate the file and the replication requirement provides a minimum number of replications to create for the file. 
     When processing a file to replicate, the content manager determines whether available remote storages in the network satisfy constraints associated with a document class of the file. The available remote storages that satisfy the geographical and the replication requirements are selected to use to replicate the file. However, if the minimum number of remote storages that satisfy a geographical requirement, such as a boundary limitation on where a file may be replicated based on where the file was created, are not available for replication, then the content manager will automatically take corrective action, such as fail the replication, perform as many of the required replications as possible, and configure additional remote storages satisfying the geographical requirement to use to complete the required replications. 
     Described embodiments improve computer technology for replicating files in an enterprise or network storage environment by having the content manager automatically determine and select available remote storages that satisfy the geographical requirements, such as boundary restrictions, based on a document class of the file to replicate and constraints associated with the document class. Further, described embodiments provide techniques for handling situations where there are not enough available remote storages that satisfy geographical limitations for replication, such as by queuing replication operations until remote storages satisfying geographical limitations become available and creating additional remote storages at geographical locations satisfying the geographical limitations. 
     Described embodiments also provide improved computer data structures to improve the management of replication operations with geographical and replication constraints, including file metadata specifying a document class used to determine the replication constraints for that document class that provides the geographical and replication requirements to use for files of that document class. Described embodiments further provide a replication queue data structure to queue files for which replication could not be completed due to a lack of available remote storages that satisfy the geographical constraints for a document class of the file, where the replication queue is used to select replications to complete when new remote storages become available. 
       FIG. 1  illustrates an embodiment of a data storage environment having a storage server  100  at which files may be uploaded and created. The storage server  100  is coupled to a local storage  102   1  over a local network  104  and various remote storages  102   2  . . .  102   n  over a network  106 , such as a Wide Area Network (WAN). The remote storages  102   2  . . .  102   n  may be may be at disparate geographical locations, such as within different jurisdictions, countries, etc. 
     In the event of a failure at the local storage  102   1 , a failover may occur to one of the remote storages  102   2  . . .  102   n , which then operates as the failover primary site. 
     The storage server  100  includes a content manager  108  to manage the storage, replication, life cycle, and synchronization of files at remote storages  102   2  . . .  102   n . The content manager  108  maintains file metadata  200  providing metadata for each file. The content manager  108  may replicate files in filsets or objects in the remote storages  102   2  . . .  102   n . The content manager  108  maintains storage metadata  300  having information on remote storages  102   2  . . .  102   n  in the network  106 . The content manager  108  further maintains constraints  400  having information on replication requirements, including geographical requirements and replication number requirements, for different classes of documents. The content manager  108  further maintains a replication queue  500  to queue files asynchronously replicated whose replication did not complete due to a lack of available remote storages  102   2  . . .  102   n  satisfying geographical requirements. 
     The constraints  400  may include a geographical requirement that indicates, for certain types of data, geographical restrictions on where the file can be replicated. For instance, if the file includes personally identifiable information (PII) or sensitive personal information (SPI), a geographical requirement may restrict the sensitive data from being replicated to certain restricted geographical locations with respect to the location where the file was created or to be limited to being stored within a national or jurisdictional boundary geographical location. For instance, PII, SPI or information including security sensitive data may not be exported or replicated outside of a national boundary of where the file was created. 
     The content manager  108  may comprise an Enterprise Content Management (ECM) platform or program, and be implemented as standalone software program on the server  100  or as software as a service (SaaS), wherein the content manager  108  is offered as a service, such as a cloud based service. 
     The storages  102   1 ,  102   2  . . .  102   n  may comprise different types or classes of storage devices, such as magnetic hard disk drives, solid state storage device (SSD) comprised of solid state electronics, EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, flash disk, Random Access Memory (RAM) drive, storage-class memory (SCM), etc., Phase Change Memory (PCM), resistive random access memory (RRAM), spin transfer torque memory (STT-RAM), conductive bridging RAM (CBRAM), magnetic hard disk drive, optical disk, tape, etc. Data in the storages  102   1 ,  102   2  , . . .  102   n    4  may further be configured from an array of devices, such as Just a Bunch of Disks (MOD), Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID) array, virtualization device, etc. Further, the storages  102   1 ,  102   2  . . .  102   n  may comprise heterogeneous storage devices from different vendors and different types of storage devices, such as a first type of storage devices, e.g., hard disk drives, that have a slower data transfer rate than a second type of storage devices, e.g., SSDs. 
     The networks  104  and  106  may comprise one or more networks including Local Area Networks (LAN), Storage Area Networks (SAN), Wide Area Network (WAN), peer-to-peer network, wireless network, the Internet, etc. 
       FIG. 2  illustrates an instance of file metadata  200   i  for a file including a unique file identifier  202 , such as a file name; an origination location  204  indicating where the file  202  was created; a document class  206  of data maintained in the file  202 , such as sensitive, e.g., PII, SPI, security, military, etc.; a replication type  208  for the file, such as synchronous or asynchronous; a repository  210  identifying storages in which the file may be replicated; and repository location  212  indicating locations in the remote storages  102   2  . . .  102   n  in which the file was replicated. 
       FIG. 3  illustrates an embodiment of an instance of storage metadata  300   i  maintained for a storage in the environment, such as one of the remote storages  102   2  . . .  102   n , and includes a storage identifier  302 , such as a network address; a geographical location  304 , such as a description or Global Positioning System (GPS) location; a storage type  306  indicating how file data is stored, such as in file sets or swift objects; and a repository  308  with which the remote storage  302  is associated. 
       FIG. 4  illustrates an embodiment of an instance of a constraint  400   i  providing geographical and replication requirements for a document class, and includes a constraint identifier  402 ; a document class  404  with which the constraint is associated, such as a particular type of sensitive data, etc.; a geographical requirement  406  indicating a geographical restriction or requirement with respect to the file; and a replication requirement  408 , such as a minimum number of replications  408  that must be created for files of the document class  404 . 
     The geographical requirement  406  may provide a geographical restriction based on an attribute of a file, such as providing a geographical boundary beyond which the file cannot be replicated based on its origination location  204 , i.e., where it was created. For instance, personally sensitive data, such as PII or SPI, may not be replicated to certain countries or must be kept within the country within which it was generated. A geographical requirement  406  may also specify a minimum or maximum distance between the remote storages  102   2  . . .  102   n  to which the file is replicated, so that the file is stored at locations that will likely not be impacted by a disaster at another location at which the file is replicated. 
       FIG. 5  illustrates an embodiment of a replication queue entry  500   i  in the replication queue  500  for a file subject to asynchronous replication that has not completed, and indicates a file to replicate  502 ; a version of the file  504 , such as time last modified; a geographic requirement  506  with respect to the replication, such as the file cannot be replicated to a location outside the nation or jurisdiction of where the file was created; and remaining replications  508  that must he performed to satisfy a replication requirement  508  associated with the file. 
     For synchronous replication, the replication will only succeed if the file is replicated to all remote storage locations that satisfy the constraints that apply to the file, and will fail if there are not enough remote storages available for immediate replication that satisfy the geographical and replication requirements. For asynchronous replication, the replication can proceed to partially replicate to only those remote storages satisfying the geographic and replication requirements that are available, and then be queued in the replication queue  500  to complete remaining replications at a later time, i.e., asynchronously, as remote storages become available that satisfy the geographical requirement  506  which previously could not be satisfied at the time of initial replication. 
       FIGS. 6 a  and 6 b    illustrate an embodiment of operations performed by the content manager  108  to replicate a file. Upon receiving (at block  600 ) a file to replicate, the content manager  108  determines (at block  602 ) a document class  206  for the file. The document class  206  may be specified by a user uploading the file to replicate or determined by scanning metadata or content in the file. The constraints  400   i  for the file are determined (at block  604 ), such as by determining the constraints  400   i  having a document class  404  matching the document class  206  of the file The content manager  108  then determines (at block  606 ) available remote storages  102   2  . . .  102   n  associated with a repository  308  matching the repository  210  used for replicas for the file  200   i . 
     If (at block  608 ) the determined constraints  400   i  include a geographical requirement  406 , then the content manager  108  determines (at block  609 ) whether a minimum number of available remote storages  102   2  . . .  102   n , specified in the replication requirement  408  satisfy a geographical requirement, e.g., the minimum number of available storage devices are within the geographical boundary specified by the geographical requirement, such as within a boundary including the origination location  204  of the file. If the minimum number of available remote storages  102   2  . . .  102   n  satisfy the geographical requirement  406 , then the content manager  108  selects (at block  612 ) the minimum number of available storage devices that satisfy the geographical requirement  406  and replicates (at block  612 ) the file to the selected remote storages  102   2  . . .  102   n . 
     If (at block  608 ) there is no geographical requirement  406  in the constraints  400   i , then the content manager  108  determines (at block  614 ) whether there are a minimum number of available remote storages, as specified in the replication requirement  408 . If so, then the minimum number of available remote storages  102   2  . . .  102   n  are selected (at block  616 ) and the file is replicated (at block  612 ) to the selected remote storages  102   2  . . .  102   n . If (at block  609  or  614 ) there are not a minimum number of available remote storages  102   2  . . .  102   n  satisfying the replication requirement  408  and any geographical requirement  406 , then control proceeds (at block  618 ) to block  620  in FIG.  6   b  where the content manager  108  determines whether the replication type  208  for the file is synchronous or asynchronous. 
     If (at block  620 ) the replication type  208  is asynchronous, then the content manager  108  determines (at block  621 ) whether at least one available remote storage  102   2  . . .  102   n  satisfies the replication  408  and any geographical  406  requirements. If (at block  620 ) there is at least one available remote storage  102   2  . . .  102   n  satisfying the constraints, then the content manager  108  replicates (at block  622 ) the file to the at least one available remote storage satisfying the replication  408  and geographical  406  requirements, if any. The content manager  108  determines (at block  624 ) a remaining number of replications by subtracting the minimum number of replications of the replication requirement  408  by the number of at least one remote storage to which the file is replicated. A replication queue entry  500   i  is added (at block  626 ) to the replication queue  500  indicating the file  502 , file version  504 , any geographical requirements  406  for the file, and the determined remaining replications  508 , determined at step  624 . The content manager  108  may then initiate (at block  628 ) configuration of a number of one or more remote storages for the remaining number of replications  508  in one or more storage devices at geographical locations that satisfy any geographical requirement  506  for the added replication queue entry  500 . A remote storage may be configured in one or more physical or virtual storage devices. 
     With the embodiments of  FIGS. 6 a  and 6 b   , the constraints for replicating a file are determined based on file metadata or user input at the time of upload. The content manager  108  may then select available remote storages  102   2  . . .  102   n  that satisfy a replication requirement of a minimum number of replication sites and a geographical requirement indicating geographical limitations for replicating the file. The file may then be automatically replicated to remote storages  102   2  . . .  102   n  when writing the file to the local storage  102   1  in a manner consistent with the replication requirements based on a document class  206  of the file, such as a type of data in the file. In this way, the user is not involved in determining the appropriate locations at which the file may be replicated which are automatically determined based on constraints defined for the document class of the file data. Further, in described embodiments, for asynchronous replication, if there are not a sufficient number of available remote storages  102   2  . . .  102   n  that satisfy replication and any geographical requirements at the time of replication, then the content manager  108  may automatically configure remote storage locations needed to complete the replication that also satisfy any geographical requirements of the constraints  400 , for the document class  206  of the file. 
       FIG. 7  illustrates an embodiment of operations performed by the content manager  108  or other component after configuring one or more new remote storage  102   N  initiated at block  628  in  FIG. 6 b    when there were not enough available remote storages  102   2  . . .  102   n  for the current replication. In response to completing (at block  700 ) configuring one or more new remote storages  102   N  throughout the network  106 , the content manager  108  adds (at block  702 ) storage metadata  300   i  for each configured remote storage  102   N  indicating the storage ID  302 , e.g., network address, geographical location  304  of the physical location of the remote storage, a storage type  306 , such as filesets, object storage, etc.; and a repository  308 , which may comprise the repository  210  for the file for which the remote storage  102   C  was configured to replicate. The first entry  500  in the replication queue  500  is accessed (at block  704 ). If (at block  706 ) the one or more configured remote storages  102   C  satisfy any geographic requirement  506 , then the content manager  108  replicates (at block  708 ) the file  502  indicated in the entry  500   i  to one or more configured remote storages  102   C  to complete as many replications as possible indicated in the remaining replications  508 . The remaining replications  508  is decremented (at block  710 ) by the number of replications performed at block  708 , if the remaining replications  508  is greater than zero. After decrementing the remaining replications (at block  710 ) or if (at block  706 ) there are no configured remote storages  102   C  that satisfy the geographic requirements  506  in the replication queue entry  500   i , the content manager  108  determines whether (at block  712 ) there are further entries  500   i+1  in the replication queue  500  following the currently accessed entry  500   i . If so, then the next entry  500   i+1  in the replication queue  500  is accessed and control proceeds back to block  706  to determine if the new configured remote storages  102   C  can be used to complete queued replications. Otherwise, control ends until further remote storages are configured or become available. 
     With the operations of  FIG. 7 , once a new remote storage is configured or a previously configured storage that was unavailable becomes available, that now available remote storage can be used to complete queued asynchronous replications that did not complete if the new configured remote storage satisfies any geographic requirement  406  of the queued file for replication. This allows automatic configuration and selection for remote storages to meet replication requirements without requiring user involvement. 
     The reference characters used herein, such as i, n are used to denote a variable number of instances of an element, which may represent the same or different values, and may represent the same or different value when used with different or the same elements in different described instances. 
     The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In sonic embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     The computational components of  FIG. 1 , including the storage servers  100  and storages  102   1  . . .  102   n , may be implemented in one or more computer systems, such as the computer system  802  shown in  FIG. 8 . Computer system/server  802  may be described in the general context of computer system executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server  802  may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices. 
     As shown in  FIG. 8 , the computer system/server  802  is shown in the form of a general-purpose computing device. The components of computer system/server  802  may include, but are not limited to, one or more processors or processing units  804 , a system memory  806 , and a bus  808  that couples various system components including system memory  806  to processor  804 . Bus  808  represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus. 
     Computer system/server  802  typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server  802 , and it includes both volatile and non-volatile media, removable and non-removable media. 
     System memory  806  can include computer system readable media in the form of volatile memory, such as random access memory (RAM)  810  and/or cache memory  812 . Computer system/server  802  may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system  813  can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus  808  by one or more data media interfaces. As will be further depicted and described below, memory  806  may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention. 
     Program/utility  814 , having a set (at least one) of program modules  816 , may be stored in memory  806  by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. The components of the computer  802  may be implemented as program modules  816  which generally carry out the functions and/or methodologies of embodiments of the invention as described herein. The systems of  FIG. 1  may be implemented in one or more computer systems  802 , where if they are implemented in multiple computer systems  802 , then the computer systems may communicate over a network. 
     Computer system/server  802  may also communicate with one or more external devices  818  such as a keyboard, a pointing device, a display  820 , etc.; one or more devices that enable a user to interact with computer system/server  802 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server  802  to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces  822 . Still yet, computer system/server  802  can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter  824 . As depicted, network adapter  824  communicates with the other components of computer system/server  802  via bus  808 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server  802 . Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc. 
     The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s)” unless expressly specified otherwise. 
     The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise. 
     The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. 
     The terms “a”, an and “the” mean “one or more”, unless expressly specified otherwise. 
     Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries. 
     A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the present invention. 
     When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the present invention need not include the device itself. 
     The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims herein after appended.