Abstract:
The embodiments are directed to methods and apparatuses for pairing delivery group machines with one or more server farms in computing networks. The methods and apparatus can allocate machines in a delivery group across one or more server farms in a manner that maximizes efficiency through better computer resource usage. The methods and apparatuses select a server farm having a largest available capacity, and allocate machines from a delivery group to the server farm. If the quantity of delivery group machines exceeds the server farm capacity, the remaining machines are allocated to a second server farm. The methods and appliances also provide for de-allocating server farms, by selecting a server farm with the least allocated capacity, and de-allocating one or more delivery group machines from the selected server farm to reduce the number of utilized server farms.

Description:
BACKGROUND 
       [0001]    Personal computers were originally created for a single user, and encompassed one or more of the following: one or more operating systems, native and third party applications, user settings, etc. Now, however, the concept of virtualization has made it easier for organizations to provide similar computational functionality, without the cost of purchasing and maintaining individual personal computers. Virtualization allows users to interact with the operating system and applications stored therein in much the same way that they would a standalone personal computer. Desktop virtualization technology allows multiple instances of an operating system to be instantiated on one or more servers (e.g., server farms), thereby allowing multiple users to login to the server and complete the same tasks that they would, as if they had their own personal computer. 
         [0002]    The architecture of the desktop virtualization environment is comprised of a collection of disparate networks. These networks can span floors in a building, or offices across several continents. The complexity of creating and maintaining these networks increases with the size of the network. Network administrators can spend weeks, if not months, properly configuring a network supporting a desktop virtualization environment. 
         [0003]    In order to provide the services offered by a desktop in a virtual environment, server farms are selected to provide the applications and programs required by users connected to a server farm. Server farms are virtual instances of physical server farms. Therefore a group of machines (e.g., a delivery group) can be used to provide any necessary hardware and software for supporting the applications and programs requested by a user connected to a server farm. The current methods and systems for assigning machines from a delivery group to a server farm are limited to assigning one delivery group to a single server farm. A delivery group can contain more machines than are required by a server farm, and therefore extra machines assigned to a server farm may go unused, resulting in inefficient resource allocation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1A  is a network diagram of an exemplary system, consistent with embodiments of the present disclosure. 
           [0005]      FIG. 1B  is an exemplary view of a user portal interface, consistent with embodiments of the present disclosure. 
           [0006]      FIGS. 2A-2B  show an exemplary computing device, consistent with the embodiments of the present disclosure. 
           [0007]      FIG. 3  is a block diagram of an exemplary user portal interface, consistent with embodiments of the present disclosure. 
           [0008]      FIG. 4  is a flowchart representing exemplary methods for allocating delivery groups across multiple server farms, consistent with embodiments of the present disclosure. 
           [0009]      FIG. 5  is a flowchart representing an exemplary method for de-allocating delivery groups across multiple server farms, consistent with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    In order to provide users with necessary resources in the most efficient way, delivery groups with adequate capacity are assigned to server farms with a corresponding capacity. This is normally accomplished by creating tables in databases that contain identifications of the server farms and the delivery groups, as well as the number of machines in a delivery group that are expected to be provided to a server farm. Current implementations only assign delivery groups with a capacity equal to the capacity of a server farm when assigning machines from a delivery group to a server farm. For example, if a server farm has the capacity to support 100 users, then a delivery group with the capacity to support 100 users would be assigned to the server farm. If, however, there is a delivery group with more capacity than a server farm, the delivery group will not be assigned to the server farm. 
         [0011]    Disclosed embodiments provide mechanisms for dividing a delivery group into more than one delivery group (e.g., delivery group splitting or server farm spanning), and assigning the divided portions of a delivery group to a server farm with matching capacity, when the delivery group capacity exceeds the server farm capacity. The current disclosure provides the ability to fully utilize the number of machines a delivery group has to offer, via delivery group splitting or server farm spanning, and allowing new server farms to be paired with delivery groups that are already assigned to a server farm, but contain more capacity than the server farm. 
         [0012]    Reference will now be made in detail to the exemplary embodiments implemented according to the present disclosure, the examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
         [0013]      FIG. 1A  is a network diagram of an exemplary system  100 , consistent with embodiments of the present disclosure. System  100  represents any type of system capable of allocating and/or de-allocating delivery groups across multiple server farms. System  100  can include, in addition to other things, a configuration device  101 , a network switch  103 , one or more server farms  105 , and one or more delivery groups  107 . 
         [0014]    Configuration device  101  is a computer program and/or terminal that can orchestrate configuration of system  100  by accessing and controlling different devices and applications in one or more server farms  105  or delivery groups  107 . Configuration device  101  can have a computer program (user portal interface  101 A) running on it that can add or remove server farms to a delivery group, or a portion of a delivery group. For example, configuration device  101  can de-allocate two machines from delivery group  107   c  that were originally assigned to server farm  105   c,  and reallocate the two machines to server farm  105   b . Configuration device  101  can determine if server farm  105   b  has enough capacity to support the two machines being allocated to server farm  105   b.  If server farm  105   b  does not contain enough capacity to support the machines, configuration device  101  can either create another server farm, and assign the machines to the new server farm, or reassign the machines to another server farm with enough capacity (e.g.,  105   a ). Moreover, configuration device  101  can define the allocation of delivery group machines across multiple server farms, which will further be described herein. 
         [0015]    Network switch  103  may include a computer networking device or computer software module that connects devices on different networks. Network switch  103 , for example, can be a server, network hub, repeater, network bridge, router, a layer-4 switch, or a layer-7 switch. Network switch  103  may receive messages from any device connected to it and transmit the message to the device or set of devices for which the message was intended. Network switch  103  can send and receive messages to the devices connected to it at layers 1, 2, 3, 4, and 7 of the Open Systems Interconnection (OSI) model. Network switch  103  can also send and receive messages using any combination of the different layers. 
         [0016]    Server farms  105 , such as server farms  105   a - c , are collections of allocated machines assigned from delivery groups  107   a - c , providing users with the ability to connect to applications (e.g., office suite products, instant messaging programs, video conferencing applications, etc.) provided by hardware and software running on the machines in the delivery groups. In some embodiments, server farms  105   a - c  can include one or more machines from a single delivery group. In some embodiments, server farms  105   a - c  can also include one or more machines from different delivery groups. For example, server farm  105   b  contains machines from delivery group B  107   b  and delivery group C  107   c.    
         [0017]    Delivery groups  107 , such as delivery groups  107   a - c , can include one or more machines such as desktop computers, databases, virtual databases, virtual desktops, and/or any other machine with a processor capable of providing applications requested by users connected to a server farm. The connections between server farms and the delivery groups can be comprised of a combination of wired and wireless networks. 
         [0018]      FIG. 1B  is an exemplary view of a user portal interface  101   a,  consistent with embodiments of the present disclosure. User portal interface  101   a,  can show one or more delivery group organized by datacenter, session machine catalog, mode of operation, capacity, and the domain that the delivery group belongs to. User portal interface  101   a  can also display multiple tabs including, but not limited to Session Machines  110 , Offerings  120 , Subscriptions  130 , Delivery Sites  140 , and Users/Tenants  150 . 
         [0019]    Session machines tab  110  can include a group of machines that are used by a server farm to provide desktop applications to users. Offerings tab  120  can include a listing of all programs (e.g., Excel, Skype, LaTeX) that can be hosted in a delivery group. Subscriptions tab  130  can include a list of subscriptions from tenants requesting services provided by one or more delivery group. Delivery sites tab  140  can include a list of different server farms, organized in ascending or descending order by health, name, location, and/or mode of operation. Users/tenants tab  150  can include a list of end user, or “tenants” using one or more delivery groups. User portal interface  101   a  may also include a search feature that allows a user to search for server farms, by name, location, health status, or mode of operation. 
         [0020]    In some embodiments, user portal interface  101   a  can also display an Edit Capacity button  160  allowing a user to increase or decrease the capacity of a server farm. User portal interface  101   a  can also display a Delete button  170  enabling a user to delete a server farm from the list of farms included in the Delivery Sites tab. User portal interface  101   a  also includes a Refresh button  180  which, when selected, can update delivery group information including: the data center, session machine catalog, mode of operation, capacity, domain, session machines, offerings, subscriptions, delivery sites, and tenants associated with a delivery group. 
         [0021]    Configuration device  101  can be deployed as a standalone device, or may be a computer module executed on a computing device configured to perform functions related to methods disclosed herein. In some embodiments, the computing device may comprise a computer or networking device capable of communicating on any type and form of network described herein. Examples of such computing devices are illustrated in  FIGS. 2A-2B . As shown in  FIGS. 2A-2B , computing device  200  may include a central processing unit (CPU)  201  and a main memory  222 . CPU  201  can be any logic circuitry that responds to and processes instructions fetched from the main memory  222 . CPU  201  can be a single or multiple processors, microprocessors, field-programmable gate arrays (FPGAs), or digital signal processors (DSPs) capable of executing particular sets of instructions stored in a memory (e.g., main memory  222 ) or cache (e.g., cache  240 ). Main memory  222  may include a tangible non-transitory computer-readable medium, such as a flexible disk, a hard disk, a CD-ROM (compact disk read-only memory), MO (magneto-optical) drive, a DVD-ROM (digital versatile disk read-only memory), a DVD-RAM (digital versatile disk random-access memory), or a semiconductor memory. Main memory  222  may include one or more memory chips capable of storing data and allowing any storage location to be directly accessed by CPU  201 . In some embodiments, main memory  222  can be any type of random access memory (RAM), or any other available memory chip capable of operating as described herein. In the exemplary embodiment shown in  FIG. 2A , CPU  201  communicates with main memory  222  via a system bus  250 . Computing device  200  can also include a visual display device  224  and one or more input/output (I/O) device  230  (e.g., a keyboard, mouse, or pointing device) connected through I/O controller  223 , both of which communicate via system bus  250 . Furthermore, I/O device  230  can also provide storage and/or an installation medium for the computing device  200 . 
         [0022]    As shown in  FIG. 2A , computing device  200  can support one or more installation device  216 , such as a floppy disk drive for receiving floppy disks such as 3.5-inch, 5.25-inch disks or ZIP disks; a CD-ROM drive; a CD-R/RW drive; a DVD-ROM drive; tape drives of various formats; a USB device; a hard-drive; or any other device suitable for installing software and programs such as any client agent  220 , or portion thereof. Computing device  200  can further comprise a storage device  228 , such as one or more hard disk drives or redundant arrays of independent disks, for storing an operating system and other related software, and for storing application software programs such as any program related to client agent  220 . Optionally, any of the installation devices  216  could also be used as storage device  228 . 
         [0023]    Furthermore, computing device  200  can include a network interface  218  to interface to a LAN, WAN, MAN, or the Internet through a variety of connections including, but not limited to, standard telephone lines, LAN or WAN links (e.g., 802.11, T1, T3, 56 kb, X.25), broadband connections (e.g., ISDN, Frame Relay, ATM), wireless connections, or some combination of any or all of the above. Network interface  218  CAN comprise a built-in network adapter, network interface card, PCMCIA network card, card bus network adapter, wireless network adapter, USB network adapter, modem or any other device suitable for interfacing computing device  200  to any type of network capable of communication and performing the operations described herein. 
         [0024]      FIG. 2B  depicts an embodiment of an exemplary computing device  200  in which CPU  201  communicates directly with main memory  222  via a memory port  203 . CPU  201  can communicate with a cache  240  via a secondary bus, sometimes referred to as a backside bus. In some other embodiments, CPU  201  can communicate with cache  240  via system bus  250 . Cache  240  typically has a faster response time than main memory  222 . In some embodiments, CPU  201  can communicate directly with I/O device  230  via an I/O port. In further embodiments, I/O device  230  can be a bridge  270  between system bus  250  and an external communication bus, such as a USB bus, an Apple Desktop Bus, an RS- 232  serial connection, a SCSI bus, a FireWire bus, a FireWire  800  bus, an Ethernet bus, an AppleTalk bus, a Gigabit Ethernet bus, an Asynchronous Transfer Mode bus, a HIPPI bus, a Super HIPPI bus, a SerialPlus bus, a SCl/LAMP bus, a FibreChannel bus, or a Serial Attached small computer system interface bus. 
         [0025]      FIG. 3  is a block diagram of an exemplary user portal interface  101   a , consistent with the embodiments of the present disclosure. In some embodiments, user portal interface  101   a  can include, among other things, database tables  310 , relational tables  320 , an end user portal  330 , and an environmental objects  340 . In some embodiments, user portal interface  101   a  may include one or more links for interfacing with database tables  310 , relational tables  320 , an end user portal  330 , and environmental objects  340 . 
         [0026]    Database table  310  can be a database that contains information related to different objects in system  100 , such as delivery groups and server farms. For example, database table  310  can provide one or more data structures showing the different delivery groups and server farms. In some embodiments, database table  310  can be implemented using a key-value pair or any other database schema. 
         [0027]    Relational table  320  may comprise one or more data structures for tracking relationships between objects in system  100  (e.g., delivery groups and server farms). For example, relational table  320  can contain data describing the pairings or allocations between a single delivery group and one or more server farms or vice versa. For instance, one delivery group can be assigned to multiple server farms using a key-value pair or any other database schema. 
         [0028]    In some embodiments, relational table  320  may store data for assigned workload details. The assigned workload details can contain, for example, one or more identifications of server farms and delivery groups, and a number (quantity) of machines a delivery group is expected to provide to a server farm. In some embodiments the assigned workload detail can also contain information identifying which machines in one or more delivery groups  107  are currently allocated to which server farm(s)  105 . 
         [0029]    End user portal  330  can be a program used to configure user programs and applications provided to a user. In some embodiments, end user portal  330  can be used by a network administrator to provide users with access to programs and applications offered by a server farm, on their personal and public devices (e.g., work desktop computer, home laptop computer, public computer, mobile device etc.). A network administrator can configure end user portal  330  to provide a user with a single consistent point of access to their desktop and applications from all of their devices. 
         [0030]    Environmental object  340  can include objects either in software or hardware related to the computing environment (e.g., server farms and delivery groups). For example, environmental object  340  can be a software object or data structure (e.g., an icon or graphical representation displayed in end user portal  330 ) associated with a server farm  105 , a delivery group  107 , and/or any combination of server farms and/or delivery groups. 
         [0031]      FIG. 4  is a flowchart representing an exemplary method for allocating delivery groups across multiple server farms, consistent with embodiments of the present disclosure. It will be readily appreciated that the illustrated procedure can be altered to delete steps or further include additional steps. While the following description is directed to the method being performed by an orchestration system configuration device (e.g., configuration device  101 ), it is appreciated that the method can be performed in whole or in part by a device other than the configuration device  101 . Moreover, in some embodiments, a user portal interface (e.g., user portal interface  101   a ) can provide an interface allowing the configuration device  101  to perform the method. 
         [0032]    After initial start step ( 400 ), the configuration device  101  receives an input to select a delivery group ( 402 ). The input can include a request for a delivery group with a certain amount of capacity, such as a particular number of machines in a delivery group to be allocated to one or more server farms. In some embodiments, the input can include a request for a delivery group that belongs to a certain datacenter or domain, or delivery group operating in a certain mode (e.g., isolation mode). 
         [0033]    In some embodiments, a delivery group can be selected based on the applications and programs needed by the users connected to a server farm. For example, an organization might be divided into multiple departments, each of which can require a unique set of programs and applications for the department employees. For instance, a marketing department may require spreadsheet programs, whereas a legal department may require word processing programs. Therefore in some embodiments a delivery group can be added to a server farm based on capacity as well as programs and applications required by a department connected to a server farm. 
         [0034]    Configuration device  101  can receive an input to select a server farm with enough capacity to meet the capacity requirements of the delivery group ( 404 ), such as a server farm that can support some or all of the quantity of delivery group machines. The selected server farm can be a virtual server farm providing programs and applications to users who are connected to the server farm through different physical networks. In some embodiments, a server farm can provide access to users who belong to the same department within a company who are geographically dispersed, but logically grouped together by a server farm. Geographically dispersed users can, in some embodiments, communicate with a server farm using a WAN, MAN, or LAN, where different geographic regions can be characterized as: different continents; different regions of a continent; different countries; different states; different cities; different campuses; different rooms; or any combination of the preceding geographical locations. 
         [0035]    After the server farm has been selected, the configuration device  101  can assign the entire delivery group to the selected server farm ( 406 ). In some embodiments, an entire delivery group can be assigned to multiple server farms. For example, a delivery group can be divided according to the applications and programs running on the machines within a delivery group, and assigned to different server farms based on the requirements of users connected to a server farm. For instance, an organization might assign different departments to different server farms and the machines in a delivery group can be assigned to server farms associated with a department based on the applications and programs required by users in a department. Therefore, a delivery group can span multiple server farms depending on the requirements of a tenant (i.e. multidepartment organization). 
         [0036]    In some embodiments, steps  402 - 406  may stand alone. For example, if the entire selected delivery group is assigned to a single server farm, the method may end after completing step  406  if no additional delivery groups are to be de-allocated. 
         [0037]    After the delivery group has been assigned to the server farm, the configuration device  101  can select any unallocated server farm that has capacity, and can assign machines from one or more delivery groups to the farm until there is no more capacity remaining in the server farm ( 408 ). As described above, in some embodiments, if a server farm is assigned to a specific set of users (e.g., marketing department), machines from different delivery groups can be assigned to the server farm, depending on the applications and programs required by users in the department until the capacity of the server farm has been filled. 
         [0038]    In step  410 , the configuration device  101  creates a list of partially allocated server farms, such as server farms  105  whose capacity has been partially filled. Configuration device  101  can select the allocated farm with the greatest amount of capacity to be filled from the list ( 412 ). In some embodiments, the list can contain multiple server farms with the same capacity. In some instances, configuration device  101  can create lists of server farms by prioritizing server farms according to applications or programs required by users using a server farm, Quality of Service requirements of a tenant, a number of users requesting access to applications and/or programs, a number of users requesting access to certain types of applications and/or programs, and/or a set of link metrics. The set of link metrics can include, but are not limited to, latency or jitter experienced by a packet as it traverses a link, a number of link segments a packet is expected to traverse, an average number of link segments a packet traverses, an expected end-to-end delay, an average end-to-end delay, throughput, department security requirements, or any other network administrator defined metrics. For example, if two server farms have the same capacity and one server farm is hosting a set of communication applications (e.g., VoIP, instant messaging applications, video conferencing applications, or other multimedia applications) requiring a greater Quality of Service and lower end-to-end delays than a server farm hosting an office suite (e.g., word processor, spreadsheet, presentation program, etc.), then the server farm hosting the communication applications will be selected first. 
         [0039]    After a server farm  105  is selected from the partially allocated server farm list, in step  414  configuration device  101  assigns machines from one or more delivery groups to the selected farm, until the capacity of the selected server farm has been met. In some embodiments, an entire delivery group can be assigned to a single partially allocated server farm, or a portion of a delivery group can be assigned to fill the remaining capacity in the partially allocated a server farm. As explained above, a delivery group can be divided according to the applications and/or programs running on the machines within a delivery group and assigned to different server farms based on the applications and programs required by the users connected to the server farm, or based on one or more link metrics or other rules established by a network administrator. 
         [0040]    In some embodiments, server farm selection ( 412 ) can be parallelized using one or more processors, and configuration device  101  can assign delivery groups to multiple server farms simultaneously without prioritizing server farms and assigning delivery groups sequentially to server farms, as described above in step  412 . 
         [0041]    After the capacity of an allocated server farm has been fulfilled, in step  416  configuration device  101  removes the allocated server farm from the list of allocated farms ( 416 ). The method can proceed to step  418  and search for other server farms with full capacity, or server farms with partial capacity. If there are server farms with full or partial capacity, the method returns to step  402  and configuration device  101  selects another delivery group. If, however there are no remaining server farms with available capacity, the method can end ( 420 ). 
         [0042]    In some embodiments, steps  402  and  408 - 416  may stand alone. For example, if the delivery group selected in step  402  is spanned across multiple server farms, then the method may perform steps  408 - 416 , and end. 
         [0043]      FIG. 5  is a flowchart representing an exemplary method for de-allocating delivery groups from one or more server farms, consistent with embodiments of the present disclosure. It will be readily appreciated the illustrated procedure can be altered to delete steps or further include additional steps. While the following description is directed to the method being performed by an orchestration system configuration device (e.g., configuration device  101 ), it is appreciated that the method can be performed in whole or in part by a device other than configuration device  101 . Moreover, in some embodiments, a user portal interface (e.g., user portal interface  101   a ) can provide an interface allowing configuration device  101  to perform the method. 
         [0044]    After initial start step ( 500 ), in step  502  configuration device  101  receives an input to select a delivery group. In some embodiments, configuration device  101  may receive the input via user portal interface  101   a.  The input can include a request to reduce the allocated capacity of a server farm or to remove one or more server farms. In some embodiments, the input can include a request for a delivery group that belongs to a certain datacenter or domain, or delivery group operating in a certain mode (e.g., isolation mode). 
         [0045]    In some embodiments, a delivery group can be selected based on the applications and programs needed by the users connected to a server farm. For example, an organization might be divided into departments each of which requires a unique set of programs and applications for the employees in that department. For instance a company might have a marketing department that uses spreadsheet programs, and a legal department that uses word processing programs. Therefore in some embodiments a delivery group can be removed from a selected server farm based on the allocated server farm capacity as well as the programs and applications required by users in a department connected to the server farm. 
         [0046]    In some embodiments, configuration device  101  can receive an input to select a server farm to which the entire delivery group is allocated ( 504 ), if the entire delivery group was previously allocated to a single server farm. The selected server farm can be a virtual server farm providing programs and applications to users, who are connected to the server farm through different physically networks. For example, a server farm can provide access to users who belong to the same department within a company who are geographically dispersed, but logically grouped together by a server farm. Geographically dispersed users can, in some embodiments, communicate with the server farm using a WAN, MAN, or LAN, where different geographic regions can be characterized as: different continents; different regions of a continent; different countries; different states; different cities; different campuses; different rooms; or any combination of the preceding geographical locations. 
         [0047]    After the server farm has been selected, configuration device  101  can un-assign (de-allocate) the entire quantity of delivery group machines from the server farm ( 506 ), and in some embodiments effectively remove the delivery group machines from service entirely. In some embodiments the entire delivery group might not be assigned to a single server farm. For example, a delivery group can be divided according to the applications and programs running on the machines within a delivery group and assigned to different server farms based on the requirements of the users connected to a server farm. For instance, an organization might assign different departments to different server farms and the machines in a delivery group can be assigned to server farms associated with a department based on the applications and programs required by users in a department. Therefore, a delivery group can span multiple server farms depending on the requirements of a tenant, and depending on the quantity of delivery group machines to de-allocate, multiple server farms may require selection for de-allocation. 
         [0048]    In some embodiments, steps  502 - 506  may stand alone. For example, if the entire selected delivery group is assigned to a single server farm, the method may end after completing step  506  if no additional delivery groups are to be de-allocated. 
         [0049]    In some embodiments where delivery group to be de-allocated are spanned across multiple server farms, configuration device  101  can select one or more allocated server farms that have a capacity (e.g. quantity of machines) currently allocated from the selected delivery group, and can de-allocate machines from one or more server farms until the indicated quantity of delivery group machines are all de-allocated ( 508 ). As described above, in some embodiments, if a delivery group is across multiple server farms, machines can be de-allocated from one or more of the server farms until the entire capacity (quantity of machines) identified in step  502  are de-allocated. 
         [0050]    In step  510 , configuration device  101  creates a list of allocated server farms containing server farms whose capacity has been partially filled with one or more machines from the selected delivery group. The list may be ordered from the least amount of allocated capacity from the delivery group, to the highest amount of allocated capacity from the delivery group. For example, if a selected delivery group has 12 machines allocated among server farms A, B, and C in the quantities/capacities of 5 machines, 3 machines, and 4 machines, respectively, then the created list may be ordered B, C, A. 
         [0051]    In step  512 , configuration device  101  can select a first server farm from the created list, such as an allocated server farm with the least amount of capacity allocated from the selected delivery group. In some embodiments, the list can contain multiple server farms with equal allocated capacities. In some instances, configuration device  101  can create lists of server farms by prioritizing server farms according to applications or programs required by users using a server farm, Quality of Service requirements of a tenant, a number of users requesting access to applications and/or programs, a number of users requesting access to certain types of applications and/or programs, and/or a set of link metrics. The set of link metrics can include but are not limited to, latency or jitter experienced by a packet as it traverses a link, a number of link segments a packet is expected to traverse, an average number of link segments a packet traverses, an expected end-to-end delay, an average end-to-end delay, throughput, department security requirements, or any other network administrator defined metrics. For example, if two server farms have the same allocated capacity and one server farm is hosting a set of communication applications (e.g., VoIP, instant messaging applications, video conferencing applications, or other multimedia applications) requiring a greater Quality of Service and lower end-to-end delays than a server farm hosting an office suite (e.g., word processor, spreadsheet, presentation program, etc.), then in some embodiments the server farm hosting the office suite can be selected first. 
         [0052]    After an allocated server farm has been selected, in step  514  configuration device  101  de-allocates one or more machines from selected delivery group from the selected server farm, until the identified capacity is completely de-allocated, or until all machines of the selected delivery group assigned to the selected server farm are de-allocated. In some embodiments, an entire delivery group can be de-allocated from a single server farm, or a portion of a delivery group can de-allocated from the selected server farm. As explained above, a delivery group can be divided according to the applications and/or programs running on the machines within a delivery group and assigned to different server farms based on the applications and programs required by the users connected to the server farm, or any other metrics or rules established by a network administrator. 
         [0053]    In some embodiments, the selecting of a farm in step  512  can be parallelized using one or more processors, and configuration device  101  can de-allocate machines of the selected delivery group from multiple server farms simultaneously without prioritizing server farms and sequentially de-allocating delivery group machines from server farms, as described above in step  512 . 
         [0054]    After the delivery group machines are de-allocated from the selected server farm, in step  516  configuration device  101  removes the allocated server farm from the list of allocated farms. The method can proceed to step  518  and to determine if additional delivery groups are to be de-allocated from one or more server farms. If there are more allocated server farms with full or partial capacities allocated to additional the selected delivery group, the method returns to step  502  and configuration device  101  selects another delivery group for de-allocation. If, however there are no farms with capacity the method can end ( 520 ). 
         [0055]    In some embodiments, steps  502  and  508 - 516  may stand alone. For example, if the delivery group selected in step  502  is spanned across multiple server farms, then the method may perform steps  508 - 516 , and end. 
         [0056]    While  FIGS. 4-5  focus on a single list of server farms, it is appreciated that more than one list can be maintained by configuration device  101 . In some embodiments, configuration device  101  can maintain multiple lists, each of which maintains a list of server farms. For example, configuration device  101  can maintain different lists of server farms corresponding to different metrics in addition to capacity requirements. For instance, a list can be created based on capacity as well as other metrics such as the average latency experienced by a packet on a connection. Alternatively a list can be created and based on the capacity and average inter-arrival time of packets on a connection. 
         [0057]    The methods disclosed herein can be implemented as a computer program product comprising computer-readable instructions. Computer-readable instructions can be stored on a tangible non-transitory computer-readable medium, such as a flexible disk, a hard disk, a CD-ROM (compact disk-read only memory), an MO (magneto-optical) disk, a DVD-ROM (digital versatile disk-read only memory), a DVD RAM (digital versatile disk-random access memory), or a semiconductor memory. Alternatively, the methods can be implemented in hardware components or combinations of hardware and software of a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. The computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. 
         [0058]    In the preceding specification, the embodiments have been described with reference to specific exemplary embodiments. It will however, be evident that various modifications and changes can be made without departing from the broader spirit and scope of the exemplary embodiments as set forth in the claims that follow. The specification and drawings are accordingly to be regarded as illustrative rather than restrictive sense. Other embodiments of the present disclosure may be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.