net.sf.basedb.core
Class InternalJobQueue

java.lang.Object
  java.util.TimerTask
      net.sf.basedb.core.InternalJobQueue

All Implemented Interfaces:

Runnable

public final class InternalJobQueue
extends TimerTask

A simple implementation of a job queue that executes jobs in order of priority and longest waiting time. To allow quick jobs like importing raw data or reporters to run it is possible to reserve slots per Job.ExecutionTime setting. The configuration is done in the base.config file with the following settings:

Setting	Default/possible value(s)	Description
jobqueue.internal.enabled	true | false	If the internal job queue is enabled or not. Do not disable the job queue if you don't have another external job queue manager. It is possible to use both an external and internal job queue.
jobqueue.internal.checkinterval	30	The interval, in seconds, that the job queue checks the database for new jobs.
jobqueue.internal.maxthreadpriority	Thread.NORM_PRIORITY - 1	The maximum thread priority for the threads that execute jobs. See Thread.setPriority(int) for possible values.
jobqueue.internal.shortest.threads	1	Number of threads to reserve for jobs with an estimated execution time of less than one minute. Jobs with this setting may also use threads from the other "slower" slots.
jobqueue.internal.shortest.threadpriority	Thread.NORM_PRIORITY - 1	The thread priority to use when executing jobs in this slot. See Thread.setPriority(int) for possible values.
jobqueue.internal.short.threads	1	Number of threads to reserve for jobs with an estimated execution time between one and ten minutes. Jobs with this setting may also use threads from the other "slower" slots.
jobqueue.internal.short.threadpriority	Thread.NORM_PRIORITY - 1	The thread priority to use when executing jobs in this slot. See Thread.setPriority(int) for possible values.
jobqueue.internal.medium.threads	2	Number of threads to reserve for jobs with an estimated execution time less than one hour. Jobs with this setting may also use threads from the other "slower" slots.
jobqueue.internal.medium.threadpriority	Thread.NORM_PRIORITY - 2	The thread priority to use when executing jobs in this slot. See Thread.setPriority(int) for possible values.
jobqueue.internal.long.threads	4	Number of threads to reserve for jobs with an estimated execution time more than one hour. Jobs with this setting may not use threads from the other slots.
jobqueue.internal.long.threadpriority	Thread.NORM_PRIORITY - 2	The thread priority to use when executing jobs in this slot. See Thread.setPriority(int) for possible values.

Version:

2.0

Author:

Nicklas

Last modified

$Date: 2010-09-13 12:36:49 +0200 (Mon, 13 Sep 2010) $

Nested Class Summary

private static class	InternalJobQueue.JobQueueKeyring Our own keyring containing the permissions we need to execute the jobs.
private class	InternalJobQueue.JobRunner Encapsulates the running of a job in a separate thread.

Field Summary

private int	closeTimeout Timeout to wait for jobs to act on the ABORT signal when shutting down BASE.
private boolean	ignoreUseInternalJobQueueFlag If the PluginDefinitionData.getUseInternalJobQueue() setting should be ignored or not.
private static Logger	log Log job queue events.
private Map<Job.ExecutionTime,Integer>	maxSlots The maximum number of threads that are allowed in each slot.
private Map<Job.ExecutionTime,Integer>	priorities The thread priority to use when executing jobs in each slot.
private Set<InternalJobQueue.JobRunner>	runners Holds all currently executing jobs.
private ThreadGroup	runnersGroup The group were all job runners are placed.
private SessionControl	sc The job queues session controller.
private static SignalReceiver	signalReceiver Use the local signal receiver only.
private Map<Job.ExecutionTime,Integer>	usedSlots The current number of threads executing in each slot.

Constructor Summary

InternalJobQueue()
Create the job queue.

Method Summary

(package private) void	close() Cleanup
static SignalReceiver	getSignalReceiver() Get the signal receiver used by the internal job queue.
private void	jobDone(InternalJobQueue.JobRunner runner) Called from a InternalJobQueue.JobRunner when it has finished executing the job.
void	run() Check the database for jobs that are waiting to be executed.
private void	sendErrorMessage(SessionControl impersonated, int jobId, Throwable ex)

Methods inherited from class java.util.TimerTask

cancel, scheduledExecutionTime

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final Logger log

Log job queue events.

sc

private final SessionControl sc

The job queues session controller. We are logging in using our own keyring: InternalJobQueue.JobQueueKeyring.

usedSlots

private final Map<Job.ExecutionTime,Integer> usedSlots

The current number of threads executing in each slot.

maxSlots

private final Map<Job.ExecutionTime,Integer> maxSlots

The maximum number of threads that are allowed in each slot.

priorities

private final Map<Job.ExecutionTime,Integer> priorities

The thread priority to use when executing jobs in each slot.

runnersGroup

private final ThreadGroup runnersGroup

The group were all job runners are placed.

runners

private final Set<InternalJobQueue.JobRunner> runners

Holds all currently executing jobs.

ignoreUseInternalJobQueueFlag

private boolean ignoreUseInternalJobQueueFlag

If the PluginDefinitionData.getUseInternalJobQueue() setting should be ignored or not.

closeTimeout

private int closeTimeout

Timeout to wait for jobs to act on the ABORT signal when shutting down BASE. Default value is 20 seconds.

signalReceiver

private static SignalReceiver signalReceiver

Use the local signal receiver only.

Constructor Detail

InternalJobQueue

InternalJobQueue()

Create the job queue. The one and only instance is created by Application.start

Method Detail

getSignalReceiver

public static SignalReceiver getSignalReceiver()

Get the signal receiver used by the internal job queue. If the internal job queue is disabled a LocalSignalReceiver is created on the first call to this method.

Returns:

A signal receiver object

Since:

2.7

run

public void run()

Check the database for jobs that are waiting to be executed. We sort the jobs by priority and creation time and try to execute them in that order. Each job is encapsulated in a InternalJobQueue.JobRunner object which is started in it's own thread.

Specified by:

run in interface Runnable

Specified by:

run in class TimerTask

jobDone

private void jobDone(InternalJobQueue.JobRunner runner)

Called from a InternalJobQueue.JobRunner when it has finished executing the job. IT MUST NEVER FORGET TO CALL THIS METHOD.

sendErrorMessage

private void sendErrorMessage(SessionControl impersonated,
                              int jobId,
                              Throwable ex)

close

void close()

Cleanup