Package org.ggf.drmaa

Interface Session

All Known Implementing Classes:
SessionImpl

public interface Session
This interface represents the operations available for interacting with the DRM. In DRMAA, (almost) all DRM interaction occur within the context of a session. The DRMAA specification also strongly recommends that a DRMAA implementation not allow concurrent sessions. Since DRMAA has no facility for user authentication or authorization, most DRMAA implementations will likely only support one session per implementation instance.

In order to use a Session, it must first be initialized. Once initialized it is the responsibility of the programmer to ensure that the session also be explicitly terminated. Otherwise, session artifacts may be left behind on the client and/or server. A handy way to make sure the Session is terminated is to set up a shutdown hook to call the exit() method on the active session.

To get a Session implementation appropriate for the DRM in use, one uses the SessionFactory.getSession() method.

Example:

public static void main(String[] args) throws Exception {
   SessionFactory factory = SessionFactory.getFactory();
   Session session = factory.getSession();

   try {
      session.init("");
      JobTemplate jt = session.createJobTemplate();
      jt.setRemoteCommand("sleeper.sh");
      jt.setArgs(Collections.singletonList("5"));

      String id = session.runJob(jt);

      session.deleteJobTemplate(jt);

      while (session.getJobProgramStatus(id) != Session.RUNNING) {
         Thread.sleep(1000);
      }

      System.out.println("Job " + id + " is now running.");

      session.control(id, Session.SUSPEND);
      Thread.sleep(1000);
      session.control(id, Session.RELEASE);

      JobInfo info = session.wait(id, Session.TIMEOUT_WAIT_FOREVER);

      System.out.println("Job " + info.getJobId () + " exited with status: " +
                         info.getExitStatus ());

      session.exit();
   }
   catch (DrmaaException e) {
      System.out.println("Error: " + e.getMessage ());
   }
 }
 
Since:
0.5
Version:
1.0
See Also:
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    Job has finished normally.
    static final int
    Job finished, but terminated abnormally.
    static final int
    Put the job on hold.
    static final String
    All jobs submitted during this DRMAA session.
    static final String
    Any job from the session.
    static final int
    Job is queued and active.
    static final int
    Release the hold on the job.
    static final int
    Resume the job.
    static final int
    Job is running.
    static final int
    Suspend the job.
    static final int
    Job is queued and in system hold.
    static final int
    Job is system suspended.
    static final int
    Kill the job.
    static final long
    Return immediately if no result is available.
    static final long
    Wait indefinitely for a result.
    static final int
    Job status cannot be determined.
    static final int
    Job is queued and in user hold.
    static final int
    Job is user suspended.
    static final int
    Job is queued and in user and system hold.
    static final int
    Job is user suspended.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    control(String jobId, int action)
    Hold, release, suspend, resume, or kill the job identified by jobId.
    Get a new job template.
    void
    Deallocate a job template.
    void
    Disengage from the DRM and allow the DRMAA implementation to perform any necessary internal cleanup.
    If called before init(), this method returns a comma delimited String containing the contact Strings available from the default DRMAA implementation, one element per DRM system available.
    If called before init(), this method returns a comma delimited list of available DRMAA implementations, one element for each DRMAA implementation provided.
    If called before init(), this method returns a comma delimited list of available DRM systems, one element per DRM system implementation provided.
    int
    Get the program status of the job identified by jobId.
    Returns a Version instance containing the major and minor version numbers of the DRMAA library.
    void
    init(String contact)
    Initialize the DRMAA implementation.
    runBulkJobs(JobTemplate jt, int start, int end, int incr)
    Submit a range of parametric jobs, each with attributes defined in the job template, jt.
    Submit a job with attributes defined in the job template, jt.
    void
    synchronize(List jobIds, long timeout, boolean dispose)
    Wait until all jobs specified by jobIds have finished execution.
    wait(String jobId, long timeout)
    This method will wait for a job with jobId to finish execution or fail.
  • Field Details

    • SUSPEND

      static final int SUSPEND
      Suspend the job. Used with the Session.control() method.
      See Also:
    • RESUME

      static final int RESUME
      Resume the job. Used with the Session.control() method.
      See Also:
    • HOLD

      static final int HOLD
      Put the job on hold. Used with the Session.control() method.
      See Also:
    • RELEASE

      static final int RELEASE
      Release the hold on the job. Used with the Session.control() method.
      See Also:
    • TERMINATE

      static final int TERMINATE
      Kill the job. Used with the Session.control() method.
      See Also:
    • JOB_IDS_SESSION_ALL

      static final String JOB_IDS_SESSION_ALL
      All jobs submitted during this DRMAA session. Used with the Session.control() and Session.synchronize() methods.
      See Also:
    • JOB_IDS_SESSION_ANY

      static final String JOB_IDS_SESSION_ANY
      Any job from the session. Used with the Session.wait() method.
      See Also:
    • TIMEOUT_WAIT_FOREVER

      static final long TIMEOUT_WAIT_FOREVER
      Wait indefinitely for a result. Used with the Session.wait() and Session.synchronize() methods.
      See Also:
    • TIMEOUT_NO_WAIT

      static final long TIMEOUT_NO_WAIT
      Return immediately if no result is available. Used with the Session.wait() and Session.synchronize() methods.
      See Also:
    • UNDETERMINED

      static final int UNDETERMINED
      Job status cannot be determined. Used with the Session.getJobProgramStatus() method.
      See Also:
    • QUEUED_ACTIVE

      static final int QUEUED_ACTIVE
      Job is queued and active. Used with the Session.getJobProgramStatus() method.
      See Also:
    • SYSTEM_ON_HOLD

      static final int SYSTEM_ON_HOLD
      Job is queued and in system hold. Used with the Session.getJobProgramStatus() method.
      See Also:
    • USER_ON_HOLD

      static final int USER_ON_HOLD
      Job is queued and in user hold. Used with the Session.getJobProgramStatus() method.
      See Also:
    • USER_SYSTEM_ON_HOLD

      static final int USER_SYSTEM_ON_HOLD
      Job is queued and in user and system hold. Used with the Session.getJobProgramStatus() method.
      See Also:
    • RUNNING

      static final int RUNNING
      Job is running. Used with the Session.getJobProgramStatus() method.
      See Also:
    • SYSTEM_SUSPENDED

      static final int SYSTEM_SUSPENDED
      Job is system suspended. Used with the Session.getJobProgramStatus() method.
      See Also:
    • USER_SUSPENDED

      static final int USER_SUSPENDED
      Job is user suspended. Used with the Session.getJobProgramStatus() method.
      See Also:
    • USER_SYSTEM_SUSPENDED

      static final int USER_SYSTEM_SUSPENDED
      Job is user suspended. Used with the Session.getJobProgramStatus() method.
      See Also:
    • DONE

      static final int DONE
      Job has finished normally. Used with the Session.getJobProgramStatus() method.
      See Also:
    • FAILED

      static final int FAILED
      Job finished, but terminated abnormally. Used with the Session.getJobProgramStatus() method.
      See Also:
  • Method Details

    • init

      void init(String contact) throws DrmaaException
      Initialize the DRMAA implementation. contact is an implementation-dependent string that may be used to specify which DRM system to use. This routine must be called before any other DRMAA calls, except for getDrmSystem(), getDrmaaImplementation(), and getContact().

      If contact is null or "", the default DRM system is used, provided there is only one DRMAA implementation available. If there is more than one DRMAA implementation available, init() throws a NoDefaultContactStringSelectedException.

      init() should be called only once, by only one of the threads. The main thread is recommended. A call to init() by another thread or additional calls to init() by the same thread with throw a SessionAlreadyActiveException.

      Parameters:
      contact - implementation-dependent string that may be used to specify which DRM system to use.
      Throws:
      DrmaaException - May be be one of the following:
      • DrmsInitException -- the session could not be initialized
      • InvalidContactStringException -- the contact string is invalid
      • AlreadyActiveSessionException -- the session has already been initialized
      • DefaultContactStringException -- no contact string was specified, and the DRMAA implementation was unable to use the default contact information to connect to a DRM
      • NoDefaultContactStringSelectedException -- no contact string was specified, and the DRMAA implementation has no default contact information
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • exit

      void exit() throws DrmaaException
      Disengage from the DRM and allow the DRMAA implementation to perform any necessary internal cleanup. This routine ends the current DRMAA session but doesn't affect any jobs which have already been submitted (e.g., queued and running jobs remain queued and running). exit() should be called only once, by only one of the threads. Additional calls to exit() beyond the first will throw a NoActiveSessionException.
      Throws:
      DrmaaException - May be one of the following:
      • DrmsExitException -- an error occured while tearing down the session
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation
    • createJobTemplate

      JobTemplate createJobTemplate() throws DrmaaException
      Get a new job template. A job template is used to set the environment for jobs to be submitted. Once a job template has been created, it should also be deleted (via deleteJobTemplate()) when no longer needed. Failure to do so may result in a memory leak.
      Returns:
      a blank JobTemplate instance
      Throws:
      DrmaaException - May be one of the following:
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation
      See Also:
    • deleteJobTemplate

      void deleteJobTemplate(JobTemplate jt) throws DrmaaException
      Deallocate a job template. This routine has no effect on jobs which have already been submitted.
      Parameters:
      jt - the JobTemplate to delete
      Throws:
      DrmaaException - May be one of the following:
      • InvalidJobTemplateException -- the JobTemplate instance does not belong to the current session, was not created with createJobTemplate(), or has already been deleted
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • runJob

      String runJob(JobTemplate jt) throws DrmaaException
      Submit a job with attributes defined in the job template, jt. The returned job identifier is a String identical to that returned from the underlying DRM system.
      Parameters:
      jt - the job template to be used to create the job
      Returns:
      job identifier String identical to that returned from the underlying DRM system
      Throws:
      DrmaaException - May be one of the following:
      • TryLaterException -- the DRM was temporarily unable to fulfill the request, but a retry might succeed
      • DeniedByDrmException -- the DRM has rejected the job due to configuration problems either in the DRM or the job template
      • InvalidJobTemplateException -- the JobTemplate instance does not belong to the current session, was not created with createJobTemplate(), or has already been deleted
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • runBulkJobs

      List runBulkJobs(JobTemplate jt, int start, int end, int incr) throws DrmaaException
      Submit a range of parametric jobs, each with attributes defined in the job template, jt. The returned job identifiers are Strings identical to those returned from the underlying DRM system. The number of jobs submitted will be Math.floor((end - start + 1) / incr).

      The JobTemplate class defines a PARAMETRIC_INDEX placeholder for use in specifying paths in the job template. This placeholder is used to represent the individual identifiers of the tasks submitted through this method.

      Parameters:
      jt - the job template to be used to create the job
      start - the starting value for the loop index
      end - the terminating value for the loop index
      incr - the value by which to increment the loop index each iteration
      Returns:
      job identifier Strings identical to that returned by the underlying DRM system
      Throws:
      DrmaaException - May be one of the following:
      • TryLaterException -- the DRM was temporarily unable to fulfill the request, but a retry might succeed
      • DeniedByDrmException -- the DRM has rejected the job due to configuration problems either in the DRM or the job template
      • InvalidJobTemplateException -- the JobTemplate instance does not belong to the current session, was not created with createJobTemplate(), or has already been deleted
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • control

      void control(String jobId, int action) throws DrmaaException

      Hold, release, suspend, resume, or kill the job identified by jobId. If jobId is JOB_IDS_SESSION_ALL, then this routine acts on all jobs submitted during this DRMAA session up to the moment control() is called. To avoid thread races conditions in multithreaded applications, the DRMAA implementation user should explicitly synchronize this call with any other job submission or control calls that may change the number of remote jobs.

      The legal values for action and their meanings are:

      • SUSPEND: stop the job,
      • RESUME: (re)start the job,
      • HOLD: put the job on-hold,
      • RELEASE: release the hold on the job, and
      • TERMINATE: kill the job.

      This method returns once the action has been acknowledged by the DRM system, but it does not necessarily wait until the action has been completed.

      Some DRMAA implementations may allow this method to be used to control jobs submitted external to the DRMAA session, such as jobs submitted by other DRMAA sessions or jobs submitted via native utilities.

      If jobId is JOB_IDS_SESSION_ALL and the control action fails for one or more jobs, and InternalException will be thrown, and the state of the jobs in the session will be undefined.

      Parameters:
      jobId - The id of the job to control
      action - the control action to be taken
      Throws:
      DrmaaException - May be one of the following:
      • ResumeInconsistentStateException -- an attempt was made to resume a job that was not is a suspended state
      • SuspendInconsistentStateException -- an attempt was made to suspend a job that was not is a running state
      • HoldInconsistentStateException -- an attempt was made to hold a job that was not is a pending state
      • ReleaseInconsistentStateException -- an attempt was made to release a job that was not is a held state
      • InvalidJobException -- the job identifier does not refer to an active job
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • synchronize

      void synchronize(List jobIds, long timeout, boolean dispose) throws DrmaaException
      Wait until all jobs specified by jobIds have finished execution. If jobIds contains JOB_IDS_SESSION_ALL, then this method waits for all jobs submitted during this DRMAA session up to the moment synchronize() is called. To avoid thread race conditions in multithreaded applications, the DRMAA implementation user should explicitly synchronize this call with any other job submission or control calls that may change the number of remote jobs.

      To prevent blocking indefinitely in this call, the caller may use a timeout specifying how many seconds to block in this call. The value TIMEOUT_WAIT_FOREVER may be specified to wait indefinitely for a result. The value TIMEOUT_NO_WAIT may be specified to return immediately if no result is available. If the call exits before the timeout has elapsed, all the jobs have been waited on or there was an interrupt. If the invocation exits on timeout, an ExitTimeException is thrown. The caller should check system time before and after this call in order to be sure of how much time has passed.

      The dispose parameter specifies how to treat the reaping of the remote jobs' internal data records, which includes a record of the jobs' consumption of system resources during their execution and other statistical information. If this parameter is set to true, the DRM will dispose of the jobs' data records at the end of the synchroniize() call. If set to false, the data records will be left for future access via the wait() method.

      Parameters:
      jobIds - the ids of the jobs to synchronize
      timeout - the maximum number of seconds to wait
      dispose - specifies how to treat reaping information
      Throws:
      DrmaaException - May be one of the following:
      • ExitTimeoutException -- the operation timed out before completing
      • InvalidJobException -- the job identifier does not refer to an active job
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
      See Also:
    • wait

      JobInfo wait(String jobId, long timeout) throws DrmaaException
      This method will wait for a job with jobId to finish execution or fail. If the special string, JOB_IDS_SESSION_ANY, is provided as the jobId, this routine will wait for any job from the session. This routine is modeled on the wait3 POSIX routine.

      The timeout value is used to specify the desired behavior when a result is not immediately available. The value, TIMEOUT_WAIT_FOREVER, may be specified to wait indefinitely for a result. The value, TIMEOUT_NO_WAIT, may be specified to return immediately if no result is available. Alternatively, a number of seconds may be specified to indicate how long to wait for a result to become available.

      If the call exits before timeout, either the job has been waited on successfully or there was an interrupt. If the invocation exits on timeout, an ExitTimeoutException is thrown. The caller should check system time before and after this call in order to be sure how much time has passed.

      The routine reaps job data records on a successful call, so any subsequent calls to wait(), synchronize(), control(), or getJobProgramStatus() will fail, throwing an InvalidJobException, meaning that the job's data record has been already reaped. This exception is the same as if the job were unknown. (The only case where wait() can be successfully called on a single job more than once is when the previous call to wait() timed out before the job finished.)

      When successful, the resource usage information for the job is provided as a Map of usage parameter names and their values in the JobInfo object. The values contain the amount of resources consumed by the job and are implementation defined. If no resource usage information is available for the finished job, the resourceUsage property of the returned JobInfo instance will be null.

      In the 0.5 version of this method, a NoResourceUsageException would be thrown if the target job finished with no resource usage information. In the current implementation, no exception is thrown in that case. Instead, the JobInfo.getResourceUsage() method will return null.

      Parameters:
      jobId - the id of the job for which to wait
      timeout - the maximum number of seconds to wait
      Returns:
      the resource usage and status information
      Throws:
      DrmaaException - May be one of the following:
      • ExitTimeoutException -- the operation timed out before completing
      • InvalidJobException -- the job identifier does not refer to an active job
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
      See Also:
    • getJobProgramStatus

      int getJobProgramStatus(String jobId) throws DrmaaException
      Get the program status of the job identified by jobId. The possible values returned from this method are:
      • UNDETERMINED: process status cannot be determined
      • QUEUED_ACTIVE: job is queued and active
      • SYSTEM_ON_HOLD: job is queued and in system hold
      • USER_ON_HOLD: job is queued and in user hold
      • USER_SYSTEM_ON_HOLD: job is queued and in user and system hold
      • RUNNING: job is running
      • SYSTEM_SUSPENDED: job is system suspended
      • USER_SUSPENDED: job is user suspended
      • USER_SYSTEM_SUSPENDED: job is user and system suspended
      • DONE: job finished normally
      • FAILED: job finished, but failed.

      The DRMAA implementation must always get the status of jobId from DRM system unless the status has already been determined to be FAILED or DONE and the status has been successfully cached. Terminated jobs return a FAILED status.

      Parameters:
      jobId - the id of the job whose status is to be retrieved
      Returns:
      the program status
      Throws:
      DrmaaException - May be one of the following:
      • InvalidJobException -- the job identifier does not refer to an active job
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • IllegalArgumentException -- an argument is invalid
      • InternalException -- an error has occured in the DRMAA implementation
    • getContact

      String getContact()
      If called before init(), this method returns a comma delimited String containing the contact Strings available from the default DRMAA implementation, one element per DRM system available. If called after init(), this method returns the contact String for the DRM system to which the session is attached. The returned String is implementation dependent.
      Returns:
      current contact information for DRM system or a comma delimited list of possible contact Strings
      Throws:
      DrmaaException - May be one of the following:
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation
    • getVersion

      Version getVersion()
      Returns a Version instance containing the major and minor version numbers of the DRMAA library. For DRMAA 0.5, major is 0 and minor is 5.
      Returns:
      the version number as a Version instance
      Throws:
      DrmaaException - May be one of the following:
      • NoActiveSessionException -- the session has not yet been initialized or has already been exited
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation
      See Also:
    • getDrmSystem

      String getDrmSystem()
      If called before init(), this method returns a comma delimited list of available DRM systems, one element per DRM system implementation provided. If called after init(), this method returns the selected DRM system. The returned String is implementation dependent.
      Returns:
      DRM system implementation information
      Throws:
      DrmaaException - May be one of the following:
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation
    • getDrmaaImplementation

      String getDrmaaImplementation()
      If called before init(), this method returns a comma delimited list of available DRMAA implementations, one element for each DRMAA implementation provided. If called after init(), this method returns the selected DRMAA implementation. The returned String is implementation dependent and may contain the DRM system as a component.
      Returns:
      DRMAA implementation information
      Throws:
      DrmaaException - May be one of the following:
      • DrmCommunicationException -- the DRMAA implementation was unable to contact the DRM
      • AuthorizationException -- the executing user does not have sufficient permissions to execute the desired action
      • InternalException -- an error has occured in the DRMAA implementation