org.globus.exec.monitoring
Class JobStateMonitor

java.lang.Object
  org.globus.exec.monitoring.JobStateMonitor

public class JobStateMonitor

extends Object

Nested Class Summary

private class

JobStateMonitor.DispatcherThread

Field Summary

private static long	CACHE_FLUSH_PERIOD Period of time between running the cache flush task.
private SortedSet	cachedEvents Time-sorted soft-state cache of events
private TimerTask	cacheFlushTask Cache flushing task.
private Date	lastEventTimestamp Timestamp of the last dispatched event.
private JobStateChangeListener	listener JobStateChangeListener which will be notified of job state changes for registered job IDs.
private static org.apache.commons.logging.Log	logger
private HashMap	mapping Mapping of Job IDs to Object keys
private static int	MAX_CACHE_AGE Maximum age of the oldest event in the soft-state cache.
private static long	RECOVERY_PERIOD Period of time between running the recovery update task.
private JobStateRecoveryListener	recoveryListener JobStateRecoveryListener which will be notified when the JSM decides that its recovery information should be updated.
private TimerTask	recoveryTask Recovery data update task.
private SchedulerEventGenerator	seg Reference to the SEG-monitoring thread.
private static Timer	timer Timer to handle all cache flushing and recovery timestamp update tasks.

Constructor Summary

JobStateMonitor(File globusLocation, String userName, String schedulerName, JobStateChangeListener listener, JobStateRecoveryListener recoveryListener)
Construct a new JobStateMonitor with a non-daemon SEG.

JobStateMonitor(File globusLocation, String userName, String schedulerName, JobStateChangeListener listener, JobStateRecoveryListener recoveryListener, boolean segDaemon)
Construct a new JobStateMonitor.

Method Summary

(package private) void	addEvent(SchedulerEvent e)
private void	cacheEvent(SchedulerEvent e) Store an event in the JobStateMonitor's cache
(package private) void	dispatchEvent(ResourceKey resourceKey, SchedulerEvent e) Call the jobStateChange callback for a SEG event.
private void	flushCache()
private List	getCachedEvents(String localId) Get all cached events associated with a Job ID.
private ResourceKey	getMapping(String localId) Look up the localId to ResourceKey mapping for a specified id.
void	registerJobID(String localId, ResourceKey resourceKey) Register a mapping from local scheduler job ID to a resource key.
void	start(Date timestamp) Start processing SEG events.
void	stop() Stop processing SEG events.
void	unregisterJobID(String localId) Unregister a local scheduler job ID for event propagation.
private void	updateRecoveryInfo()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logger

private static org.apache.commons.logging.Log logger

seg

private SchedulerEventGenerator seg

Reference to the SEG-monitoring thread.

listener

private JobStateChangeListener listener

JobStateChangeListener which will be notified of job state changes for registered job IDs.

recoveryListener

private JobStateRecoveryListener recoveryListener

JobStateRecoveryListener which will be notified when the JSM decides that its recovery information should be updated.

mapping

private HashMap mapping

Mapping of Job IDs to Object keys

cachedEvents

private SortedSet cachedEvents

Time-sorted soft-state cache of events

MAX_CACHE_AGE

private static final int MAX_CACHE_AGE

Maximum age of the oldest event in the soft-state cache.

See Also:

Constant Field Values

CACHE_FLUSH_PERIOD

private static final long CACHE_FLUSH_PERIOD

Period of time between running the cache flush task.

See Also:

Constant Field Values

RECOVERY_PERIOD

private static final long RECOVERY_PERIOD

Period of time between running the recovery update task.

See Also:

Constant Field Values

timer

private static Timer timer

Timer to handle all cache flushing and recovery timestamp update tasks.

cacheFlushTask

private TimerTask cacheFlushTask

Cache flushing task. Every CACHE_FLUSH_PERIOD milliseconds, cache entries older than MAX_CACHE_AGE will be discarded.

recoveryTask

private TimerTask recoveryTask

Recovery data update task. Every RECOVERY_PERIOD milliseconds, recoveryListener's updateJobMonitorRecoveryTimeStamp() will be called to have it update the persistent state of the JobStateMonitor.

lastEventTimestamp

private Date lastEventTimestamp

Timestamp of the last dispatched event. This timestamp is used as the safe-recovery timestamp when the soft-state event cache is empty, but some events have been dispatched to their JobStateChangeListener or discarded from the soft-state cache by the cacheFlushTask.

Constructor Detail

JobStateMonitor

public JobStateMonitor(File globusLocation,
                       String userName,
                       String schedulerName,
                       JobStateChangeListener listener,
                       JobStateRecoveryListener recoveryListener)

Construct a new JobStateMonitor with a non-daemon SEG. The new JobStateMonitor will not begin the Scheduler Event Generator automatically. Services which create a JobStateMonitor may register any number of job ID mappings before calling start() to start the SEG.

Parameters:

globusLocation - Path to the Globus Toolkit installation.

userName - User name that the SEG should run as (via sudo(8)). (Currently ignored).

schedulerName - Name of the scheduler SEG module to use.

listener - Reference to the JobStateChangeListener which will be notified when notifications relating to Job ID which has a mapping registered to it.

recoveryListener - Reference to a JobStateRecoveryListener which will be notified periodically when the JobStateMonitor wants to update its recovery checkpoint timestamp.

JobStateMonitor

public JobStateMonitor(File globusLocation,
                       String userName,
                       String schedulerName,
                       JobStateChangeListener listener,
                       JobStateRecoveryListener recoveryListener,
                       boolean segDaemon)

Construct a new JobStateMonitor. The new JobStateMonitor will not begin the Scheduler Event Generator automatically. Services which create a JobStateMonitor may register any number of job ID mappings before calling start() to start the SEG.

Parameters:

globusLocation - Path to the Globus Toolkit installation.

userName - User name that the SEG should run as (via sudo(8)). (Currently ignored).

schedulerName - Name of the scheduler SEG module to use.

listener - Reference to the JobStateChangeListener which will be notified when notifications relating to Job ID which has a mapping registered to it.

recoveryListener - Reference to a JobStateRecoveryListener which will be notified periodically when the JobStateMonitor wants to update its recovery checkpoint timestamp.

segDaemon - Indicates whether to make the SEG a daemon thread or not

Method Detail

registerJobID

public void registerJobID(String localId,
                          ResourceKey resourceKey)
                   throws AlreadyRegisteredException

Register a mapping from local scheduler job ID to a resource key. Once this method has been called for a particular local job identifier, the JobStateChangeListener associated with the JobStatemonitor may receive notifications until the unregisterJobIDMap method has been called.

Parameters:

localId - Local job identifier. This is presumably generated by the scheduler when the job is created.

resourceKey - Resource key associated with the job. This object will be passed to the JobStateChangeListener's jobStateChange method.

Throws:

AlreadyRegisteredException

start

public void start(Date timestamp)
           throws IllegalThreadStateException

Start processing SEG events. Starts the SEG thread processing events from the scheduler, as well as some background tasks to flush cache of old job events and to update the persistent timestamp used for restarting the JobStateMonitor.

Parameters:

timestamp - Date from which to start processing events. If null, then the SEG will process events generated from the time the function is called.

Throws:

IllegalThreadStateException - This method has already been called.

stop

public void stop()
          throws IOException

Stop processing SEG events. Blocks the current thread until the SEG has terminated. No furthur SEG events will be issued after method returns until the start() method is called again.

Throws:

IOException

flushCache

private void flushCache()

updateRecoveryInfo

private void updateRecoveryInfo()

getCachedEvents

private List getCachedEvents(String localId)

Get all cached events associated with a Job ID.

Parameters:

localId - Job identifier to look up.

Returns:

Returns a list of SchedulerEvents associated with the Job ID.

unregisterJobID

public void unregisterJobID(String localId)
                     throws NotRegisteredException

Unregister a local scheduler job ID for event propagation. Once this method has been called for a particular local job identifier, the JobStateChangeListener associated with the JobStatemonitor will no longer receive notifications about this job.

Parameters:

localId - Local job identifier.

Throws:

NotRegisteredException

cacheEvent

private void cacheEvent(SchedulerEvent e)

Store an event in the JobStateMonitor's cache

getMapping

private ResourceKey getMapping(String localId)

Look up the localId to ResourceKey mapping for a specified id.

addEvent

void addEvent(SchedulerEvent e)

dispatchEvent

void dispatchEvent(ResourceKey resourceKey,
                   SchedulerEvent e)

Call the jobStateChange callback for a SEG event.

Parameters:

resourceKey - Resource key associated with the job ID in the event.

e - Event containing the job state change information.