org.globus.exec.monitoring
Class SchedulerEventGenerator

java.lang.Object
  java.lang.Thread
      org.globus.exec.monitoring.SchedulerEventGenerator

All Implemented Interfaces:

Runnable

class SchedulerEventGenerator

extends Thread

Scheduler Event Generator monitor thread. The Seg object creates a Scheduler Event Generator process to monitor job state changes associated with a particular scheduler. The Seg object will repeatedly start the SEG process if it terminates prematurely, until its shutdown() method is called.

Field Summary

private File	globusLocation Path to the SEG executable
private long	lastRestart Used to keep track of the last restart time for the SEG process---if it was too recent (less than our THROTTLE_RESTART_THRESHOLD) wait THROTTLE_RESTART_TIME before trying again.
private static org.apache.commons.logging.Log	logger
private JobStateMonitor	monitor Monitor which created this SchedulerEventGenerator.
private Process	proc SEG Process handle
private static Runtime	runtime Reference to the runtime used to start the SEG process
private String	schedulerName Path to the SEG executable
private static String	SEG_EXECUTABLE_NAME
private boolean	shutdownCalled Flag indicating that the SEG process should no longer be restarted and the thread should terminate.
private long	THROTTLE_RESTART_THRESHOLD When SEG terminates within this amount of time of being started, assume something might be wrong and delay again.
private long	THROTTLE_RESTART_TIME When throttling process restarts, wait this many milliseconds before next restart attempt.
private Date	timeStamp Timestamp of last event we've received from a SEG.
private String	userName Username of the account to run the SEG as.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

SchedulerEventGenerator(File globusLocation, String userName, String schedulerName, JobStateMonitor monitor)
SEG constructor.

Method Summary

private void	cleanProcess()
void	run() Start and monitor a SEG process.
void	shutdown() Tell a SEG process to terminate.
void	start(Date timeStamp)
private boolean	startSegProcess(Date timeStamp) Start a scheduler event generator process.
private void	throttleRestart() Delay THROTTLE_RESTART_TIME before returning unless either The SEG process wasn't restarted within THROTTLE_RESTART_THRESHOLD The shutdown method has been called

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

logger

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

runtime

private static Runtime runtime

Reference to the runtime used to start the SEG process

globusLocation

private File globusLocation

Path to the SEG executable

userName

private String userName

Username of the account to run the SEG as. This is currently ignored.

schedulerName

private String schedulerName

Path to the SEG executable

proc

private Process proc

SEG Process handle

shutdownCalled

private boolean shutdownCalled

Flag indicating that the SEG process should no longer be restarted and the thread should terminate.

timeStamp

private Date timeStamp

Timestamp of last event we've received from a SEG.

monitor

private JobStateMonitor monitor

Monitor which created this SchedulerEventGenerator. We call its addEvent() method when a new event is read from the SEG process.

lastRestart

private long lastRestart

Used to keep track of the last restart time for the SEG process---if it was too recent (less than our THROTTLE_RESTART_THRESHOLD) wait THROTTLE_RESTART_TIME before trying again.

THROTTLE_RESTART_TIME

private final long THROTTLE_RESTART_TIME

When throttling process restarts, wait this many milliseconds before next restart attempt.

See Also:

Constant Field Values

THROTTLE_RESTART_THRESHOLD

private final long THROTTLE_RESTART_THRESHOLD

When SEG terminates within this amount of time of being started, assume something might be wrong and delay again.

See Also:

Constant Field Values

SEG_EXECUTABLE_NAME

private static final String SEG_EXECUTABLE_NAME

See Also:

Constant Field Values

Constructor Detail

SchedulerEventGenerator

public SchedulerEventGenerator(File globusLocation,
                               String userName,
                               String schedulerName,
                               JobStateMonitor monitor)

SEG constructor.

Parameters:

globusLocation - Path to the Globus Toolkit installation.

userName - Username to sudo(8) to start the SEG.

schedulerName - Name of the scheduler SEG module to use (fork, lsf, etc).

Method Detail

run

public void run()

Start and monitor a SEG process. When the SEG terminates by itself for whatever reason, this thread will restart it using the timestamp of the last item which was in the event cache.

startSegProcess

private boolean startSegProcess(Date timeStamp)
                         throws IOException

Start a scheduler event generator process. This function is called to start a new scheduler event generator process. This process will monitor the output of the scheduler and send this object job state change notifications via the processes's standard output stream. If the shutdown method of this object has been called, then the process will not be started.

Throws:

IOException

throttleRestart

private void throttleRestart()

Delay THROTTLE_RESTART_TIME before returning unless either

• The SEG process wasn't restarted within THROTTLE_RESTART_THRESHOLD
• The shutdown method has been called

cleanProcess

private void cleanProcess()

shutdown

public void shutdown()
              throws IOException

Tell a SEG process to terminate. This function will cause the thread associated with this object to terminate once all input has been processed.

Throws:

IOException

start

public void start(Date timeStamp)