Package com.tangosol.coherence.commonj

Class WorkManager

  • All Implemented Interfaces:
    commonj.work.WorkManager
    public class WorkManager
extends Base
implements commonj.work.WorkManager
    An implementation of commonj.work.WorkManager based on a joint BEA-IBM specification: "The Timer and Work Manager for Application Servers", which is a foundation of JSR 237: Work Manager for Application Servers.

    Implementation notes:

    • The WorkManager is constructed using a unique name; there could be one and only one manager per cluster node with this name. This name will also be the name of the underlying InvocationService instance used by the WorkManager. The WorkManagers running on different cluster nodes that have the same name will form a pool of available WorkManager threads.
    • The WorkManager is constructed using a number of threads dedicated for Work processing; if this value is zero, this WorkManager instance will run in a "client-only" role, meaning that it will not accept any work load sent by other WorkManager clients.
    • The WorkManage could be constructed with a specific ConfigurableCacheFactory. In this case, the WorkManager name will be used to instantiate the corresponding InvocationService.
    • This WorkManager implementation allows client to request current "work in progress" feedback via getCurrentResult(commonj.work.WorkItem) method.
    • The specification does not explicitly specify what response should be if a remote server crashes during an execution. Current implementation uses WORK_COMPLETED with WorkCompletedException as a result. It's important to understand that in a generic case it's impossible to know whether or not a Work has been completed.
    • If a Work originator Member terminates before the Work gets started, the remote server will still run it.
    • Only serializable Work (standard or POF) is currently supported.
    Note: The WorkManager is a feature of the Coherence Enterprise Edition and Coherence Grid Edition. It cannot be used in a Coherence Standard Edition cluster.

    See Also:
    WorkManager and Timers: Utilities for J2EE programmers
    Timer and Work Manager for Application Servers

    • Field Detail

      • m_workObserver

        protected InvocationObserver m_workObserver
        The ScheduleWork agent observer.

    • Constructor Detail

      • WorkManager

        public WorkManager​(String sManagerName,
                   int cThreads)
        Construct the WorkManager.
        Parameters:
        sManagerName - a unique WorkManager name
        cThreads - number of threads dedicated for Work processing; zero for WorkManagers in a "client-only" role

      • WorkManager

        public WorkManager​(String sManagerName,
                   ConfigurableCacheFactory factory)
        Construct the WorkManager using the specified ConfigurableCacheFactory.
        Parameters:
        sManagerName - a unique WorkManager name
        factory - ConfigurableCacheFactory that will be used to instantiate the corresponding InvocationService using the factory.ensureService(sManagerName) call

    • Method Detail

      • init

        protected void init​(String sManagerName,
                    int cThreads,
                    ConfigurableCacheFactory factory)
        Initialization.
        Parameters:
        sManagerName - a unique WorkManager name
        cThreads - number of threads
        factory - ConfigurableCacheFactory to use

      • installMemberListener

        protected void installMemberListener()
        Install a MemberListener.

      • instantiateWorkObserver

        protected void instantiateWorkObserver()
        Instantiate a Work observer.

      • collectMembershipInfo

        protected void collectMembershipInfo()
        Inform all the members about this node's role (client or server) and collect the information regarding other nodes' roles

      • schedule

        public commonj.work.WorkItem schedule​(commonj.work.Work work)
                               throws commonj.work.WorkException
        Dispatches a Work asynchronously. The work is dispatched and the method returns immediately.

        At-most-once semantics are provided. If the server fails then the Work will not be executed on restart.

        Specified by:
        schedule in interface commonj.work.WorkManager
        Parameters:
        work - the Work to execute.
        Returns:
        the WorkItem representing the asynchronous work; since the Work must be serializable, a RemoteWorkItem is always returned
        Throws:
        commonj.work.WorkException - thrown if queuing this up results in an exception

      • schedule

        public commonj.work.WorkItem schedule​(commonj.work.Work work,
                                      commonj.work.WorkListener workListener)
                               throws commonj.work.WorkException
        Dispatches a Work asynchronously. The work is dispatched and the method returns immediately.

        At-most-once semantics are provided. If the server fails then the Work will not be executed on restart.

        Specified by:
        schedule in interface commonj.work.WorkManager
        Parameters:
        work - the Work to execute
        workListener - an optional WorkListener which is used to inform the application of the progress of a Work
        Returns:
        the WorkItem representing the asynchronous work; since the Work must be serializable, a RemoteWorkItem is always returned
        Throws:
        commonj.work.WorkException - thrown if queuing this up results in an exception

      • schedule

        protected commonj.work.WorkItem schedule​(commonj.work.Work work,
                                         commonj.work.WorkListener workListener,
                                         Member member)
                                  throws commonj.work.WorkException
        Accepts a Work instance for processing at the specified Member.
        Parameters:
        work - the Work to execute
        workListener - an optional WorkListener which is used to inform the application of the progress of a Work
        member - the Member to execute the Work at
        Returns:
        a WorkItem representing scheduled Work
        Throws:
        commonj.work.WorkException - thrown if queuing this up results in an exception

      • waitForAll

        public boolean waitForAll​(Collection collWorkItems,
                          long lTimeoutMillis)
                   throws InterruptedException
        Wait for all WorkItems in the collection to finish. If there are no WorkItems in the list then it returns immediately indicating a timeout. WorkItems from different WorkManagers can be placed in a single collection and waited on together.

        The WorkItems collection should not be altered once submitted until the method returns.

        Specified by:
        waitForAll in interface commonj.work.WorkManager
        Parameters:
        collWorkItems - the Collection of WorkItem objects to wait for
        lTimeoutMillis - the timeout in milliseconds. If this value is zero then this method returns immediately
        Returns:
        true if all WorkItems have completed; false if the timeout has expired
        Throws:
        InterruptedException - thrown if the wait is interrupted
        IllegalArgumentException - thrown if workItems is null, any of the objects in the collection are not WorkItems or the timeout is negative

      • waitForAny

        public Collection waitForAny​(Collection collWorkItems,
                             long lTimeoutMillis)
                      throws InterruptedException
        Wait for any of the WorkItems in the collection to finish. If there are no WorkItems in the list then it returns immediately indicating a timeout. WorkItems from different WorkManagers can be placed in a single collection and waited on together.

        The WorkItems collection should not be altered once submitted until the method returns.

        Specified by:
        waitForAny in interface commonj.work.WorkManager
        Parameters:
        collWorkItems - the Collection of WorkItem objects to wait for
        lTimeoutMillis - the timeout in ms. If this value is zero then the method returns immediately, i.e. does not block
        Returns:
        the WorkItems that have completed or an empty Collection if its timeout expires before any finished
        Throws:
        InterruptedException - thrown if the wait is interrupted
        IllegalArgumentException - thrown if workItems is null, any of the objects in the collection are not WorkItems or the timeout is negative

      • getCurrentResult

        public WorkManager.WorkStatus getCurrentResult​(commonj.work.WorkItem item)
        Retrieve a current WorkStatus (partial result) for a given Work.

        If the specified work has not been rejected or completed, this method will always communicate with a remote server to retrieve the current WorkStatus.

        Parameters:
        item - the WorkItem to retrieve the status for
        Returns:
        the corresponding WorkStatus object

      • getService

        public InvocationService getService()
        Return an InvocationService used by this WorkManager.
        Returns:
        an InvocationService used by this WorkManager

      • getServers

        public Set<Member> getServers()
        Return a set of Members that run the same Invocation service as this WorkManager in a "server" capacity.
        Returns:
        a set of server Members

      • getPostedWork

        public Map<Long,​WorkManager.WorkHolder> getPostedWork()
        Return a catalog of WorkHolder objects for all posted Work as known by the client side keyed by the corresponding work id.
        Returns:
        the Map of posted WorkHolder objects

      • getAcceptedWork

        public Map<Member,​Map<Long,​WorkManager.ScheduleWork>> getAcceptedWork()
        Return a catalog of accepted ScheduleWork tasks as known by the server side keyed by the origin Member where the value is a map of ScheduleWork tasks keyed by the WorkId.
        Returns:
        a catalog of started ScheduleWork tasks

      • isServer

        public boolean isServer()
        Check whether or not this node operates in a "server" mode processing remote Work requests.
        Returns:
        true if this node operates in a "server" mode processing remote Work requests; false otherwise

      • disableServer

        public void disableServer​(Member member)
        Remove a Member from a list of active server nodes and terminate all work posted to that server. This method could be called by the client code in response to exceptions (i.e. serialization problems) thrown by a server that deem further use of that server impossible.
        Parameters:
        member - the Member to remove from the server list

      • cancelPostedWork

        public void cancelPostedWork()
        Cancel all posted work that has not yet completed.

      • chooseServer

        protected Member chooseServer()
        Choose a Member to run a next Work at.

        Called by client threads.

        Returns:
        the Member to run a next Work at

      • getPostedWork

        protected WorkManager.WorkHolder getPostedWork​(long lWorkId)
        Return a WorkHolder for a posted work with a given id.
        Parameters:
        lWorkId - a work id
        Returns:
        a WorkHolder for a given work id

      • removePostedWork

        protected WorkManager.WorkHolder removePostedWork​(long lWorkId)
        Remove a WorkHolder for a posted work with a given id.
        Parameters:
        lWorkId - a work id
        Returns:
        a WorkHolder for a given work id

      • generateWorkId

        protected int generateWorkId()
        Generate a unique (for this WorkManager) work id.

        Called by client threads.

        Returns:
        the generated Work id

      • processFeedback

        protected void processFeedback​(WorkManager.SendFeedback workFeedback)
        Process a remote work feedback.

        Called by the InvocationService on the service thread at the client VM.

        Parameters:
        workFeedback - the feedback Work object

      • updateWork

        protected boolean updateWork​(WorkManager.WorkStatus status)
        Update a WorkStatus for a work. If the corresponding WorkHolder has already been released, no action takes place.

        Called by the InvocationService on a service thread of the client VM.

        Parameters:
        status - a WorkStatus object with an new status
        Returns:
        true iff the status was updated; false if the corresponding work has already been released

      • initWork

        protected void initWork​(WorkManager.ScheduleWork workAgent)
        Initialize the remote work agent.

        Called by the InvocationService on the service thread of the server member.

        Parameters:
        workAgent - the agent Work object

      • processWork

        protected WorkManager.WorkStatus processWork​(WorkManager.ScheduleWork workAgent)
        Run the remote work agent.

        Called by a daemon thread of the InvocationService on a server VM.

        Parameters:
        workAgent - the agent Work object
        Returns:
        the WorkStatus object

      • requestWorkStatus

        protected WorkManager.WorkStatus requestWorkStatus​(WorkManager.RequestStatus requestAgent)
        Obtain current status of the specified Work.

        Called by a daemon thread of the InvocationService on a server VM.

        Parameters:
        requestAgent - the request status
        Returns:
        the corresponding WorkStatus object

      • releaseWork

        protected void releaseWork​(WorkManager.ReleaseWork releaseAgent)
        Release the remote work agent.

        Called by a daemon thread of the InvocationService on a server VM.

        Parameters:
        releaseAgent - the release work

      • main

        public static void main​(String[] asArg)
        Entry point: start a stand-alone WorkManager (server) using the specified name and thread count. 
         Example:
   java com.tangosol.coherence.commonj.WorkManager Manager 5
        Parameters:
        asArg - the command line arguments