Abstract:
Methods and apparatus, including computer program products, for control interfaces for distributed system applications. A method includes, at an application deployed on a first computing system in a grid computing environment, monitoring a communication channel connecting the first computing system to a second computing system, receiving a command over the communication channel from the second computing system, and in response to the received command, generating a descriptor file including descriptions of one or more actions to be performed by the second computing system in order to move the application from the first computing system to a third computing system.

Description:
BACKGROUND  
       [0001]     This description relates to control interfaces for distributed system applications.  
         [0002]     Grid computing is a form of distributed system wherein computing resources are shared across networks. Grid computing enables the selection, aggregation, and sharing of information resources resident in multiple administrative domains and across geographic areas. These information resources are shared, for example, based upon their availability, capability, and cost, as well as a user&#39;s quality of service (QoS) requirements. Grid computing can reduce cost of ownership, aggregate and improve efficiency of computing, data, and storage resources, and enable the creation of virtual organizations for applications and data sharing.  
       SUMMARY  
       [0003]     The techniques described in this specification provide methods and apparatus, including computer program products, for control interfaces for distributed system applications.  
         [0004]     In an aspect, a method includes, at an application deployed on a first computing system in a grid computing environment, monitoring a communication channel connecting the first computing system to a second computing system, receiving a command over the communication channel from the second computing system, in response to the received command, and generating a descriptor file including descriptions of one or more actions to be performed by the second computing system in order to move the application from the first computing system to a third computing system. and terminating execution of the application.  
         [0005]     In embodiments, the method can include, at the first computing system, terminating execution of the application. The method can include at the second computing system, receiving the descriptor file including action descriptions, and using the action descriptions to move the application from the first computing system to the third computing system. The method can include, at the third computing system in the grid computing environment, starting execution of the application.  
         [0006]     The descriptor file can be an extended markup language (XML) file. The action descriptions can include at least one of a set of command line parameters to be passed to the application at startup to initiate application execution at the third computing system, and a set of files associated with the application to be copied to the third computing system.  
         [0007]     The application can be a mobile agent and the first descriptor file can include an empty list. The first computing system can be a first computational resource, the second computing system can be a grid resource manager, and the third computing system can be a second computational resource.  
         [0008]     In another aspect, a method includes, at an application deployed on a first computing system in a grid computing environment, monitoring a communication channel connecting the first computing system to a second computing system, receiving a command over the communication channel from the second computing system, and in response to the received command, generating a descriptor file including descriptions of one or more actions to be performed by the second computing system in order to start the application.  
         [0009]     In embodiments, the method can include, at the first computing system, terminating execution of the application. The method can include at the second computing system, receiving the descriptor file including action descriptions, and using the action descriptions to start the application at the first computing system.  
         [0010]     The descriptor file can be an extended markup language (XML) file. The action descriptions can include at least one of a set of command line parameters to be passed to the application at startup to initiate application execution, and a set of log files.  
         [0011]     The first computing system can be a computational resource and the second computing system can be a grid resource manager.  
         [0012]     The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.  
     
    
     DESCRIPTION OF DRAWINGS  
       [0013]      FIG. 1  is block diagram.  
         [0014]      FIGS. 2   a  and  2   b  are flow diagrams.  
         [0015]      FIGS. 3   a  and  3   b  are flow diagrams.  
         [0016]      FIGS. 4   a  and  4   b  are flow diagrams. 
     
    
       [0017]     Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0018]     As shown in  FIG. 1 , a grid computing environment  100  includes a set of computational resources  102 ,  104 ,  106 . The computational resources  102 ,  104 ,  106  communicate with each other through a network  108 . The network  108  can be a local area network (LAN) or a larger group of interconnected systems, such as the Internet.  
         [0019]     Each computational resource  102 ,  104 ,  106  is associated with a grid manager  102   a,    104   a,    106 a. The grid managers  102   a,    104   a,    106   a  handle numerous functions, such as, for example, facilitating installation and de-installation of applications  102   b,    104   b,    106   b  on the computational resources 102 ,  104 ,  106 . Allocating and de-allocating computational resources  102 ,  104 ,  106  allows the computational resources  102 ,  104 ,  106  in the grid computing environment  100  to be designated as general-purpose computational resources that may be used by a number of applications on an “as needed” basis, rather than solely dedicated to a single application all of the time.  
         [0020]     Each grid manager  102   a,    104   a,    106   a  monitors resource utilization on its associated computational resource  102 ,  104 ,  106  and sends this utilization information to a grid resource manager  110  in response to a resource utilization query. In one example, the grid resource manager  110  sends a resource utilization query to one or more grid managers  102   a,    104   a,    106   a  prior to deploying an application in the grid computing environment  100 . Responses to the resource utilization query are used by the grid resource manager  110  to determine if there are computational resources  102 ,  104 ,  106  in the grid computing environment  100  that match the computational resource requirements of the application (“application requirements”) to be deployed. These computational resource requirements specify information pertaining to a computational resource  102 ,  104 ,  106 , such as required number of processors, required percentage of utilization for those processors, main memory, operating system and network speed.  
         [0021]     The grid resource manager  110  receives the utilization information from the grid managers  102   a,    104   a,    106   a  and compares the received utilization information with the application requirements to identify the computational resources that satisfy the application requirements. The grid resource manager  110  selects, from among the identified computational resources, at least one computational resource  102 ,  104 ,  106  and sends a reservation request to the grid manager  102   a,    104   a,    106   a  associated with the selected computational resource  102 ,  104 ,  106 .  
         [0022]     If the selected computational resource  102 ,  104 ,  106  is available for application deployment and the reservation succeeds, the grid manager  102   a,    104   a,    106   a  associated with the selected computational resource  102 ,  104 ,  106  sends a reservation number to the grid resource manager  110 . This reservation number indicates to the grid resource manager  110  that the selected computational resource  102 ,  104 ,  106  has been guaranteed to the application to be deployed. The grid resource manager  110  deploys the application  102   b,    104   b,    106   b  by instructing the grid manager  102   a,    104   a,    106   a  associated with the selected computational resource  102 ,  104 ,  106  to install and run the application on the selected computational resource  102 ,  104 ,  106 .  
         [0023]     Once deployed, an entry including an application identifier and a computational resource identifier is added to an application deployment file  110   a  maintained by the grid resource manager  110 . The application identifier uniquely identifies the deployed application; the computational resource identifier uniquely identifies the computational resource  102 ,  104 ,  106  on which the application is deployed. Other information may be included in an entry of the application deployment file  110   a,  for example, a high or low priority designation, a runtime of the application, and the application requirements.  
         [0024]     Upon deployment, each application  102   b,    104   b,    106   b  opens and listens to a communication channel  102   c,    104   c,    106   c  during execution. In one implementation, an application listens for commands at a specific TCP/IP port that is specified at startup. In another implementation, an application exposes a Web service during execution through which the grid resource manager  110  issues commands to the application.  
         [0025]     Each application  102   b,    104   b,    106   b  that is deployed in the grid computing environment  100  can be implemented with a control interface  102   d,    104   d,    106   d  that enables the grid resource manager  110  to control and manage the operation of the application  102   b,    104   b,    106   b  upon request. The interface defines a set of commands, such as “suspend”, “continue”, “stop_persistent”, and “move”. The operations associated with each of these commands will be described in more detail in examples to follow.  
         [0026]     As shown in  FIGS. 2   a  and  2   b,  in one example, all of the computational resources  102 ,  104 ,  106  in the grid computing environment  100  are busy running applications when the grid resource manager  110  receives ( 202 ) a request, e.g., from a user, to deploy an application having a high priority designation, also referred to as a high-priority application. Rather than wait for a computational resource  102 ,  104 ,  106  to become available, the grid resource manager  110  may be requested or instructed to suspend the execution of an application having a low priority designation, also referred to as a low-priority application, so that the high-priority application may be deployed and run on that computational resource  102 ,  104 ,  106 .  
         [0027]     In one implementation, the grid resource manager  110  examines the application deployment file  110   a  to identify ( 204 ) the computational resources  102 ,  104 ,  106  that are currently running low-priority applications. The grid resource manager  110  then sends ( 206 ) a resource utilization query to the grid managers  102   a,    104   a,    106   a  associated with the identified computational resources  102 ,  104 ,  106 as previously-described. The grid resource manager  110  compares ( 208 ) the received utilization information (e.g., responses to the query) with the application requirements of the high-priority application.  
         [0028]     If none of the computational resources  102 ,  104 ,  106  are identified as satisfying the application requirements, a “deployment failure” alert may be generated by the grid resource manager and sent ( 210 ) to the application deployment request source, e.g., the user. The grid resource manager may provide a manual override feature that enables the application deployment request source to designate a computational resource to which the high-priority application is to be deployed regardless of the priority designation of the application that is currently being executed on that computational resource.  
         [0029]     If at least one computational resource is identified ( 212 ) as satisfying the application requirements, the grid resource manager selects ( 214 ) one of the low-priority applications from among the low-priority applications deployed on the identified computational resources  102 ,  104 ,  106 . In one implementation, the low-priority application (“selected low-priority application”) having the longest runtime is selected by the grid resource manager  110 . The grid resource manager  110  sends ( 216 ) a “suspend= 38  command to the selected low-priority application over its corresponding communication channel.  
         [0030]     Upon receipt ( 218 ) of the “suspend” command, the selected low-priority application suspends ( 220 ) execution at the computational resource and sends ( 222 ) an “acknowledge” command to the grid resource manager to indicate that the selected low-priority application has been placed in a “suspend” state. In the “suspend” state, the selected low-priority application consumes, for example, main memory, disk space, network connections of the computational resource, but not its processing power.  
         [0031]     While the low-priority application is in the “suspend” state, the grid resource manager deploys ( 224 ) the high-priority application as previously-described. The deployed high-priority application may be implemented to send a “terminated” command to the grid resource manager to signal the completion of the execution of the high-priority application.  
         [0032]     Upon receipt ( 226 ) of the “terminated” command, the grid resource manager sends ( 228 ) a “continue” command to the suspended low-priority application over the communication channel. The suspended low-priority application receives ( 230 ) the “continue” command and resumes ( 232 ) execution at the computational resource and sends ( 234 ) an “acknowledge” command to the grid resource manager to indicate that the application has been removed from the “suspend” state and placed in a “normal” state. In the “normal” state, the low-priority application resumes consumption of processing power.  
         [0033]     As shown in  FIG. 3 , in another example, multiple applications are deployed in the grid computing environment  100 . One such application is a resource-intensive application (e.g., an application for running large-scale numerical simulations) that may be run concurrently on multiple computational resources  102 ,  104 ,  106  to reduce overall runtime.  
         [0034]     In one implementation, the grid resource manager periodically sends ( 302 ) a resource utilization query to the grid managers  102   a,    104   a,    106   a  in the grid computing environment  100  to determine which computational resources  102 ,  104 ,  106  are available (i.e., no applications are deployed on the computational resource) or under-utilized (i.e., the resources consumed by an application running on the computational resource are less than a predetermined threshold). The grid resource manager compares ( 304 ) the received utilization information with the application requirements of the resource-intensive application and identifies ( 306 ) the computational resources  102 ,  104 ,  106  that satisfy the application requirements. The grid resource manager then selects ( 308 ) one or more of the identified computational resources  102 ,  104 ,  106  for allocation to the resource-intensive application.  
         [0035]     If a selected computational resource  102 ,  104 ,  106  is available, the grid resource manager deploys ( 310 ) the resource-intensive application as previously-described.  
         [0036]     If a selected computational resource  102 ,  104 ,  106  is under-utilized, the grid resource manager sends ( 312 ) a “stop_persistent” command to the application X over its corresponding communication channel. Upon receipt ( 314 ) of the “stop_persistent” command, the application X generates ( 316 ) an application restart file, such as an eXtended Markup Language (XML) file, that describes the information that the grid resource manager will use to restart the application X at a later time. The information in the application restart file can include, for example, one or more command line parameters that have to be passed to the application X at startup in order to initiate application execution at the selected computational resource  102 ,  104 ,  106 , and copies of the log files. Log files are generated by the application itself. A task is to copy these files to a destination node in order to have continuous log files.  
         [0037]     The application restart file is sent ( 318 ) to the grid resource manager. Upon receipt ( 320 ) of the application restart file, the grid resource manager sends ( 322 ) an “acknowledge” command to the application X that results in the termination ( 324 ) of the application X at the selected computational resource  102 ,  104 ,  106 , and the placement of the application X in a “stop_persistent” state in which the application X only consumes disk space. The disk space may be local to the selected computational resources  102 ,  104 ,  106  or located on a remote computational resource  102 ,  104 ,  106  accessible via the network.  
         [0038]     The grid resource manager may then deploy ( 326 ) the resource-intensive application to the selected computational resource  102 ,  104 ,  106  as previously-described. In one example, after a specific period of time has elapsed, the grid resource manager may terminate ( 328 ) the resource-intensive application and use ( 330 ) the application restart file to restart ( 332 ) the stopped application X at the selected computational resource  102 ,  104 ,  106 , e.g., by passing the command line parameters specified in the application restart file to the stopped application X.  
         [0039]     In another example, a number of applications are deployed on computational resources  102 ,  104 ,  106  in the grid computing environment  100  when the grid resource manager receives ( 402 ) a request, e.g., from a user, to deploy an application (e.g., “application A”). The grid resource manager sends ( 404 ) a resource utilization query to all of the grid managers  102   a,    104   a,    106   a  in the grid computing environment  100  as previously-described. The grid resource manager compares ( 406 ) the received utilization information with the application requirements of the application A and identifies ( 408 ) the computational resources  102 ,  104 ,  106  that satisfy the application requirements.  
         [0040]     If at least one of the identified computational resources  102 ,  104 ,  106  is available for application deployment, the grid resource manager selects ( 410 ) one of the available computational resources  102 ,  104 ,  106  and deploys ( 412 ) the application A as previously-described.  
         [0041]     If none of the identified computational resources  102 ,  104 ,  106  are available, the grid resource manager examines ( 414 ) the application deployment file  110   a  and selects, from among the applications deployed on the identified computational resources  102 ,  104 ,  106 , an application (e.g., “application B”) that may be deployed on a computational resource  102 ,  104 ,  106  (“computational resource N) different from the one (”computational resource M”) on which it is currently-deployed. Factors that contribute to the selection of the application B include the uniqueness of the application requirements of the application B, and the priority designation and/or runtime of the application B.  
         [0042]     The grid resource manager sends ( 416 ) a “move” command to the application B over its corresponding communication channel. Upon receipt ( 418 ) of the “move” command, the application B generates ( 420 ) an application move file, such as a XML file, that describes the information that the grid resource manager will use to move the application B from the computational resource M to the computational resource N. The information in the application move file can include, for example, a list of files that have to be copied to a certain location (e.g., the computational resource N or a database) and one or more command line parameters that have to be passed to the application B at startup in order to initiate application execution at the computational resource N.  
         [0043]     If the application B is a mobile agent (i.e., an application that can transfer itself from one computational resource to another), then the generated application move file may be an empty list that is used to signal the grid resource manager that the application B received the “move” command.  
         [0044]     The generated application move file is sent ( 422 ) to the grid resource manager. Upon receipt ( 424 ) of the application move file, the grid resource manager sends ( 426 ) an “acknowledge” command to the application B that results in the termination ( 428 ) of application B at the computational resource M. The grid resource manager  110  then uses ( 430 ) the application move file to move the application B from the computational resource M to the computational resource N. Once the application B is successfully moved, the grid resource manager  110  uses ( 432 ) the application move file to restart ( 434 ) the application B at the computational resource N, e.g., by passing the command line parameters specified in the application move file to the application B. The grid resource manager also deploys the application A to the currently-available computational resource M as previously described.  
         [0045]     The techniques described herein can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The techniques can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A 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 stand-alone 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.  
         [0046]     Method steps of the techniques described herein can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Method steps can also be performed by, and apparatus of the invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). Modules can refer to portions of the computer program and/or the processor/special circuitry that implements that functionality.  
         [0047]     Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry.  
         [0048]     The techniques described herein can be implemented in a distributed computing system that includes a back-end component, e.g., as a data server, and/or a middleware component, e.g., an application server, and/or a front-end component, e.g., a client computer having a graphical user interface and/or a Web browser through which a user can interact with an implementation of the invention, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet, and include both wired and wireless networks.  
         [0049]     The computing system can include clients and servers. A client and server are generally remote from each other and typically interact over a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.  
         [0050]     Other embodiments are within the scope of the following claims. The following are examples for illustration only and not to limit the alternatives in any way. The techniques described herein can be performed in a different order and still achieve desirable results.