Patent Publication Number: US-11025518-B2

Title: Communicating health status when a management console is unavailable

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a computer program product, system, and method for communicating health status when a management console is unavailable for a server in a mirror storage environment. 
     2. Description of the Related Art 
     In a storage environment, primary and secondary storage servers may maintain mirror copy relationships, where a primary volume in a mirror copy relationship comprises the storage or volumes from which data is physically copied to a secondary volume. A server and storage involved in the mirror copy relationships may be implemented in a storage system, such as the International Business Machine Corporation&#39;s (“IBM”) DS8000®, which also includes a hardware management console (HMC) that is a dedicated workstation physically located inside the DS8000 storage system. The HMC may proactively monitor the state of the storage system and notify an administrator or a remote monitoring service when service and repairs are required. The storage system may further include multiple server components, or storage facility Central Electronic Complexes (CECs), and disk enclosures for disk drives implementing the storage. When the storage systems, such as the DS8000s, are deployed in a mirror storage environment, the data may be mirrored among the storages implemented in the storage system, which connect over a network. 
     In certain implementations, the HMC may connect to the CECs or processing complexes over a dedicated network, which is separate from the network used to mirror data between the storage systems. 
     There is a need in the art for improved techniques for monitoring and reporting the health status in a mirror copying relationship. 
     SUMMARY 
     Provided are a computer program product, system, and method for communicating health status when a management console is unavailable for a server in a mirror storage environment. A determination at a first server is made that a management console is unavailable over the console network. The first server determines a health status at the first server and the first storage in response to determining that the management console cannot be reached over the console network. The health status indicates whether there are errors or no errors at the first server and the first storage. The first server transmits the determined health status to the second server over a mirroring network mirroring data between the first storage and a second storage managed by the second server. The determined health status is forwarded to an administrator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an embodiment of a mirror storage environment. 
         FIG. 2  illustrates an embodiment of a health status message. 
         FIG. 3  illustrates an embodiment of operations to monitor a management console of a storage system. 
         FIG. 4  illustrates an embodiment of operations to transmit a health status message to a remote server in a mirror storage environment. 
         FIG. 5  illustrates an embodiment of operations for a server to process a health status message received from a remote server in the mirror storage environment. 
         FIG. 6  illustrates an embodiment of a computer architecture used with described embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     A management console in a storage system, such as a Hardware Management Console (HMC), may become unavailable because of a failure of the management console or the network connecting the management console to a storage system processing facility. In such case, the management console may not be able to detect errors in the storage system, such as failures of a storage device or other component, which are non-disruptive errors that do not prevent the storage system from participating in the mirror storage environment. However, such non-disruptive errors, if not addressed, may result in greater problems if another component fails, which in combination with the previous non-disruptive failure, results in a catastrophic failure of the storage system. For instance, failure of one hard disk drive in a Redundant Array of Independent Disks (RAID) may not result in data failure because the RAID controller may be able to reconstruct data using the parity information. However, if the failed hard disk drive is not replaced, then failure of another hard disk drive may result in multiple disk drives failing, which the RAID controller may not be able to error correct. In such case, the failure of the management console to detect errors or failures not causing the storage system to fail may eventually result in a catastrophic failure. 
     Described embodiments address the above problems by monitoring whether the management console is available over a console network separate from the network over which data is mirrored. If the management console is unavailable, then a health status at a server and/or a storage managed by the server is determined. The server transmits the determined health status to a remote server involved in mirroring data over a mirroring network used to mirror data among servers. The server receiving the health status may then forward the health status to an administrator, such as by forwarding the received health status to a management console coupled to the receiving server over a separate management console network connected to the receiving server. 
     With the described embodiment, detected errors and component failures may be reported over a mirroring network when they cannot be communicated over a management console network over which they are normally monitored. This allows errors to be detected, reported and addressed to avoid further failures, including possible catastrophic failure. 
       FIG. 1  illustrates a mirroring storage environment having a first server  100   a , second server  100   b , and at least one additional server  100   c  that manage a first storage  102   a , a second storage  102   b , and at least one additional storage  102   c , respectively. A host (not shown) may access volumes  106   a ,  106   ab , and additional volumes (not shown) configured in the first storage  102   a , the second storage  102   b , and the at least one additional storage  102   c . The primary server  100   a , the secondary server  100   b , and the at least one additional server  100   c  may mirror data in their respective storage  102   a ,  102   b ,  102   c  over a mirroring network  108 . 
     Each server  100   a ,  100   b  includes a processor  110   a ,  110   b , comprising one or more processor devices, and a memory  112   a ,  112   b . Each memory  112   a ,  112   b  includes a storage manager  114   a ,  114   b  to manage read and write access to the respective storage  102   a ,  102   b  from a host; a copy manager  116   a ,  116   b  to mirror data between the servers  100   a ,  100   b ; a health monitor  118   a ,  118   b  to monitor the health of components in the servers  100   a ,  100   b , including the management console  124   a ,  124   b , and generate a health status message  200   a ,  200   b  indicating a health condition detected by the health monitor  118   a ,  118   b  with respect to the server  100   a ,  100   b , storage  102   a ,  102   b , and management console  124   a ,  124   b , respectively; a cache  120   a ,  120   b  to cache read and write data with respect to the volumes  106   a ,  106   b  in the respective primary  102   a  and secondary  102   b  storages. The copy managers  116   a ,  116   b  may generate mirror copy relationship information  122   a ,  122   b  having information on mirror copy relationships of volumes  106   a ,  106   b  in the first storage  102   a  and second storage  102   b  subject to mirror copying of data there between, respectively. 
     Volumes  106   a ,  106   b  configured in the storages  102   a ,  102   b , respectively, may comprise a Logical Unit Number (LUN), Logical Subsystem (LSS), or any grouping of tracks, where a track may comprise a block, track or any data unit. 
     The first server  100   a  and second server  100   b  each are coupled to a management console  124   a ,  124   b  over separate console networks  126   a ,  126   b , respectively. The management consoles  124   a ,  124   b  comprise separate computer systems with which the servers  100   a  and  100   b  communicate. The servers  100   a ,  100   b  may provide status information to an administrator operating the management consoles  124   a ,  124   b , and the administrator may configure the servers  100   a ,  100   b  through the respective management console  124   a ,  124   b , such as configure volumes  106   a ,  106   b  and mirror copy relationships  122   a ,  122   b.    
     The management console networks  126   a ,  126   b  may be implemented in hardware separate from the mirroring network  108 . For instance, the servers  100   a ,  100   b  may include separate adaptor ports to communicate with hardware and switches implementing the console network  126   a ,  126   b  and the hardware and switches implementing the mirroring network  108 . Using different ports, virtual or physical, in the servers  100   a ,  100   b  to connect to the different mirroring  108  and console  126   a ,  26   b  networks maintains the networks separate from each other. 
     In certain embodiments, the mirroring network  108  may only be used to copy data being mirrored as indicated in mirror copy relationships  122   a ,  122   b  while the respective management consoles  124   a ,  124   b  are available over the console networks  126   a ,  126   b . Further, the console networks  126   a ,  126   b  may only be used for communications between the servers  100   a  and  100   b  and their respective management consoles  124   a ,  124   b.    
     In certain embodiments, data in volumes  106   a  in the first storage  102   a  may be mirrored to volumes  106   b  in the second storage  102   b  according to configured mirror copy relationships  122   a ,  122   b . Further, the data mirrored from the first storage  102   a  to the second storage  102   b  may further be mirrored to at least one additional storage  102   c  either from the first server  100   a  or the second server  100   b  upon receiving data mirrored from the first server  100   a . Further, additional servers  100   c  may mirror data from one to the other, and the second server  100   b  may mirror data from the second storage  102   b  to other of the servers  100   a ,  100   c . The additional servers  100   c , additional storage  102   c  and additional management consoles  124   a  for the additional servers  100   c  may have the same arrangement and components as described with respect to the servers  100   a ,  100   b , storages  102   a ,  102   b , and management consoles  124   a ,  124   b . Data may also be mirrored from the second storage  102   b  and additional storages  102   c  to any other storage  102   a ,  102   b ,  102   c.    
     In one embodiment, the first server  100   a , first storage  102   a , and first management console  124   a  and the second server  100   b , second storage  102   b , and second management console  124   b  may be implemented as components in first and second storage system enclosures, respectively, such as the International Business Machines Corporation (IBM®) DS8000® and DS8880 storage systems. Further, in each storage system, there may be multiple servers, implemented as redundant storage facility Central Electronic Complexes (CECs), with redundant storage and redundant connections to the mirroring network  108  and console networks  126   a ,  126   b . (IBM and DS8000 are trademarks of International Business Machines Corporation throughout the world). 
     The mirroring  108  and console networks  126   a ,  126   b  may comprise a Storage Area Network (SAN), Wide Area Network (WAN), Local Area Network (LAN), the Internet, and Intranet, a wireless network, wired network, etc. Additionally, the networks  108 ,  126   a ,  126   b  may be implemented using other types of bus or network interfaces, including a Peripheral Component Interconnect Express (PCIe) bus. 
     The storages  102   a ,  102   b ,  102   c  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 (STM-RAM), conductive bridging RAM (CBRAM), magnetic hard disk drive, optical disk, tape, etc. The volumes  106   a ,  106   b  may further be configured from an array of devices, such as Just a Bunch of Disks (JBOD), Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID) array, virtualization device, etc. Further, the storages  102   a ,  102   b  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 components, such as the storage manager  114   a ,  114   b , copy manager  116   a ,  116   b , and health monitor  118   a ,  118   b  may be implemented in computer readable program instructions in a computer readable storage medium executed by a processor and/or computer hardware, such as an Application Specific Integrated Circuit (ASIC). 
       FIG. 2  illustrates an embodiment of a health status message  200   i , such as health status messages  200   a ,  200   b , generated by the health monitor  118   a ,  118   b  upon detecting a health condition or error affecting access to the volumes  106   a ,  106   b , and includes: a message identifier (ID)  202 ; a health status  204  indicating there is no problem or indicating the type of error or health condition with respect to the server  206  components and storage; a server ID  206  indicating the server  100   a ,  100   b  for which the health status  204  is generated; one or more volumes and/or storage devices  208  impacted by the health condition; a severity level  210  of the health condition, e.g., minor, acute, severe, etc.; a management console ID  212  of a management console  124   a ,  126   b  at the server  206 ; and a management console status  214  indicating whether the management console  214  is operational or unavailable. 
     The health status  204  may indicate a hardware error in the server  206  or storage  102   a ,  102   b  managed by the server  206  that may be resolved by fixing or replacing the hardware or storage devices, such as errors in in a device or host adaptor in the server  206 , and other software and/or hardware errors, etc. The management console status  214  may indicate hardware or software errors in the identified management console  212  or the console network  126   a ,  126   b  over which the management console  212  connects to the server  206 . 
     An administrator being notified of the health status message  200   i , which may surface at a management console  124   a ,  124   b , may then take appropriate action to replace hardware or fix errors at the server  206 , the storage  102   a ,  102   b  and/or the management console  212  based on the health status  204  and management console status  214 . The health status  204  may indicate that there is no problem with the health of the server  206  and the managed volumes  208 , but the management console status  214  may indicate an error or problem with the management console  212 , such as that it is unavailable. Still further, the health status  204  may indicate an error with the server  206  and managed volumes  208  and the management console status  214  may indicate unavailability of the management console  212 , indicating both need to be fixed or repaired. 
       FIG. 3  illustrates an embodiment of operations performed by the health monitor  118   a ,  118   b  or other component in the server  100   a ,  100   b  to generate a health status message  200   a ,  200   b . The local server  100   a ,  100   b  in which the health monitor  118   a ,  188   b  is operating may comprise a primary server mirroring data to the secondary server, or may be the secondary server receiving data to store at the secondary site. Upon the health monitor  118   a ,  118   b  periodically (at block  300 ) initiating monitoring of the management console  124   a ,  124   b , a heartbeat signal is sent (at block  302 ) to the connected management console  124   a ,  124   b  over the console network  126   a ,  126   b . If (at block  304 ) a response to the heartbeat signal is not received within a predetermined time period, then the health monitor  118   a ,  118   b  determines (at block  306 ) a health status at the local server  100   a ,  100   b  and local storage  102   a ,  102   b , including any software or hardware errors in the volumes  106   a ,  106   b  or storage devices of the local storage  102   a ,  102   b , where an error may comprise a partial or total failure of a component or program operations. The health monitor  118   a ,  118   b  generates (at block  308 ) a health status message  200   a ,  200   b  indicating the local server identifier  206 , any determined errors in the local server in health status field  204 , any errors in the local storage (e.g., failed volumes and storage devices) in field  208 , a severity level  210  of any errors, a management console identifier  212  of the non-responsive management console  124   a ,  124   b , and that the management  212  console is unavailable in the management console status field  214 . The health status message  200   a ,  200   b  is transmitted (at block  310 ) over the mirroring network  100  to a connected remote server  100   b ,  100   a  to surface the health status to an administrator. 
     If (at block  304 ) the heartbeat signal is received, then control ends because any errors or problems with any components at the local server  100   a ,  100   b  or local storage  102   a ,  102   b  would surface at the connected management console  124   a ,  124   b.    
     With the described embodiment of operations of  FIG. 3 , the mirroring network  108 , which is otherwise exclusively used for data mirroring operations, is used to transmit health status information when one of the servers  100   a ,  100   b  cannot communicate with the connected management console  124   a ,  124   b . This allows any problems or errors to surface at another console or device operated by the administrator so that the administrator is made aware of the problems and can fix or replace any failed parts to avoid future problems which could be catastrophic. For instance, a failure of a storage device in the storage  102   a ,  102   b  may not currently effect operations at the storage  102   a ,  102   b  if error recovery methods, such as Redundant Array of Independent Disk (RAID) and error correction codes (ECC), are able to recover data on the failed storage device. However, it is important to alert the administrator of such errors immediately to replace or fix the failed storage device because failure of an additional storage device at the storage  102   a ,  102   b  may prevent data from being recovered. 
     In certain embodiments, to transmit the health status message  200   a ,  200   b  when there are additional servers  100   c  and storages  102   c  in the mirror storage environment, the health monitor  118   a ,  118   b  may broadcast the generated health status message  200   a ,  200   b  to all remote servers  100   b ,  100   a ,  100   c  in the environment as a broadcast message. 
       FIG. 4  illustrates an embodiment of operations performed by the health monitor  118   a ,  118   b  to transmit the health status message  200   a ,  200   b  when there are multiple remote servers  100   a ,  100   b  and  100   c  in the storage environment to which the local server  100   a ,  100   b  may transmit health status. Upon initiating (at block  400 ) an operation to transmit the health status message  200   a ,  200   b  to additional servers  100   b ,  100   b ,  100   c  in the mirror storage environment, the health monitor  118   a ,  118   b  determines (at block  402 ) whether there are available paths to multiple remote servers  100   b ,  100   a  and  100   c  in the mirroring network  108  among which data is mirrored. The health monitor  118   a ,  118   b  selects (at block  404 ) one of the remote servers  100   b ,  100   a ,  100   c  for which there is an available path in the mirroring network  108 . The health monitor  118   a ,  118   b  then transmits (at block  406 ) the health status message  200   a ,  200   b  to the selected remote server over the mirroring network  108  used to mirror data to the remove server. 
       FIG. 5  illustrates an embodiment of operations performed by a health monitor  118   a ,  118   b  or other component at a server receiving a health status message  200   a ,  200   b . Upon a server  100   a ,  100   b ,  100   c  referred to as the local server, receiving (at block  500 ) a health status message  200   i  from a remote server, i.e., the server  100   a ,  100   b ,  100   c  sending the health status message  200   i  over the mirroring network  108 , the health monitor  118   a ,  118   b  determines (at block  502 ) whether the local management console  124   a ,  124   b  is available over the local console network  126   a ,  126   b . If so, then the health monitor  118   a ,  118   b  transmits (at block  504 ) the health status message  200   i  to the local management console  124   a ,  124   b  to surface to an administrator to take action to fix or repair any problems with the server  100   a ,  100   b ,  100   c , or connected storage  102   a ,  102   b ,  102   c  resulting in the health status message  200   i , and the unavailable management console  212 . 
     If (at block  502 ) the local management console  124   a ,  124   b  is not available, then a determination is made (at block  506 ) whether an additional server  100   c  in the mirroring network  108  is available. If so, then the health monitor  118   a ,  118   b  transmits (at block  508 ) the health status message  200   i  to the at least one additional server  100   c  available in the mirroring network  108 . Otherwise, if an additional server  100   c  is not available to surface the error message, including unavailability of a management console  124   a ,  124   b ,  124   c , then an internal error message or notification at the local server is generated, to provide at an output device at the local server or to output to another location. 
     In described embodiments, the health status message  200   i  is sent to another server  100   a ,  100   b ,  100   c  in the mirror network  108  to surface at a management console at another server. Alternatively, the health status message may be transmitted through a third channel, such as a separate network, independent of the mirroring  108  and console networks  126   a ,  126   b , to a remote system to provide to the administrator. 
     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 some 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 servers  100   a ,  100   b ,  100   c  and management consoles  124   a ,  124   n ,  124   c  may be implemented in one or more computer systems, such as the computer system  602  shown in  FIG. 6 . Computer system/server  602  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  602  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. 6 , the computer system/server  602  is shown in the form of a general-purpose computing device. The components of computer system/server  602  may include, but are not limited to, one or more processors or processing units  604 , a system memory  606 , and a bus  608  that couples various system components including system memory  606  to processor  604 . Bus  608  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  602  typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server  602 , and it includes both volatile and non-volatile media, removable and non-removable media. 
     System memory  606  can include computer system readable media in the form of volatile memory, such as random access memory (RAM)  610  and/or cache memory  612 . Computer system/server  602  may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system  613  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  608  by one or more data media interfaces. As will be further depicted and described below, memory  606  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  614 , having a set (at least one) of program modules  616 , may be stored in memory  606  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  602  may be implemented as program modules  616  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  602 , where if they are implemented in multiple computer systems  602 , then the computer systems may communicate over a network. 
     Computer system/server  602  may also communicate with one or more external devices  618  such as a keyboard, a pointing device, a display  620 , etc.; one or more devices that enable a user to interact with computer system/server  602 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server  602  to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces  622 . Still yet, computer system/server  602  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  624 . As depicted, network adapter  624  communicates with the other components of computer system/server  602  via bus  608 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server  602 . 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.