org.apache.activemq.store.kahadb.scheduler

Class JobSchedulerImpl

java.lang.Object

org.apache.activemq.util.ServiceSupport

org.apache.activemq.store.kahadb.scheduler.JobSchedulerImpl

All Implemented Interfaces:

Runnable, JobScheduler, Service

public class JobSchedulerImpl
extends ServiceSupport
implements Runnable, JobScheduler

Method Summary

Modifier and Type	Method and Description
void	addListener(JobListener l) Add a Job listener which will receive events related to scheduled jobs.
protected void	doStart()
protected void	doStop(ServiceStopper stopper)
List<Job>	getAllJobs() Get all the outstanding Jobs
List<Job>	getAllJobs(long start, long finish) Get all outstanding jobs due to run between start and finish
protected List<org.apache.activemq.store.kahadb.scheduler.JobLocation>	getAllScheduledJobs(Transaction tx) Walks the Scheduled Job Tree and collects the add location and last update location for all scheduled jobs.
String	getName()
List<Job>	getNextScheduleJobs() Get all the jobs scheduled to run next
long	getNextScheduleTime() Get the next time jobs will be fired
protected void	mainLoop()
protected void	process(Transaction tx, KahaAddScheduledJobCommand command, Location location) Adds a new Scheduled job to the index.
protected void	process(Transaction tx, KahaRemoveScheduledJobsCommand command, Location location) Removes all scheduled jobs within a given time range.
protected void	process(Transaction tx, KahaRescheduleJobCommand command, Location location) Reschedules a Job after it has be fired.
void	remove(long time) remove all jobs scheduled to run at this time
void	remove(String jobId) remove a job with the matching jobId
protected void	removeAll(Transaction tx) Removes all jobs from the schedulers index.
void	removeAllJobs() remove all the Jobs from the scheduler
void	removeAllJobs(long start, long finish) remove all the Jobs from the scheduler that are due between the start and finish times
protected void	removeInRange(Transaction tx, long start, long finish, Location location) Removes all scheduled jobs within the target range.
protected boolean	removeJobAtTime(Transaction tx, String jobId, long executionTime) Removes a Job from the index using it's Id value and the time it is currently set to be executed.
void	removeListener(JobListener l) remove a JobListener that was previously registered.
void	run()
void	schedule(String jobId, ByteSequence payload, long delay) Add a job to be scheduled
void	schedule(String jobId, ByteSequence payload, String cronEntry) Add a job to be scheduled
void	schedule(String jobId, ByteSequence payload, String cronEntry, long delay, long period, int repeat) Add a job to be scheduled
void	setName(String name)
void	startDispatching() Starts dispatch of scheduled Jobs to registered listeners.
void	stopDispatching() Stops dispatching of scheduled Jobs to registered listeners.
String	toString()
void	write(DataOutput out)

Methods inherited from class org.apache.activemq.util.ServiceSupport

addServiceListener, dispose, isStarted, isStopped, isStopping, postStop, preStart, removeServiceListener, start, stop

Methods inherited from class java.lang.Object

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

Method Detail

setName

public void setName(String name)

getName

public String getName()

Specified by:

getName in interface JobScheduler

Returns:

the name of the scheduler

addListener

public void addListener(JobListener l)

Description copied from interface: JobScheduler

Add a Job listener which will receive events related to scheduled jobs.

Specified by:

addListener in interface JobScheduler

Parameters:

l - The job listener to add.

removeListener

public void removeListener(JobListener l)

Description copied from interface: JobScheduler

remove a JobListener that was previously registered. If the given listener is not in the registry this method has no effect.

Specified by:

removeListener in interface JobScheduler

Parameters:

l - The listener that should be removed from the listener registry.

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     long delay)
              throws IOException

Description copied from interface: JobScheduler

Add a job to be scheduled

Specified by:

schedule in interface JobScheduler

Parameters:

jobId - a unique identifier for the job

payload - the message to be sent when the job is scheduled

delay - the time in milliseconds before the job will be run

Throws:

IOException

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     String cronEntry)
              throws Exception

Description copied from interface: JobScheduler

Add a job to be scheduled

Specified by:

schedule in interface JobScheduler

Parameters:

jobId - a unique identifier for the job

payload - the message to be sent when the job is scheduled

cronEntry - The cron entry to use to schedule this job.

Throws:

Exception - if an error occurs while scheduling the Job.

schedule

public void schedule(String jobId,
                     ByteSequence payload,
                     String cronEntry,
                     long delay,
                     long period,
                     int repeat)
              throws IOException

Description copied from interface: JobScheduler

Add a job to be scheduled

Specified by:

schedule in interface JobScheduler

Parameters:

jobId - a unique identifier for the job

payload - the message to be sent when the job is scheduled

cronEntry - cron entry

delay - time in ms to wait before scheduling

period - the time in milliseconds between successive executions of the Job

repeat - the number of times to execute the job - less than 0 will be repeated forever

Throws:

IOException

remove

public void remove(long time)
            throws IOException

Description copied from interface: JobScheduler

remove all jobs scheduled to run at this time

Specified by:

remove in interface JobScheduler

Parameters:

time - The UTC time to use to remove a batch of scheduled Jobs.

Throws:

IOException

remove

public void remove(String jobId)
            throws IOException

Description copied from interface: JobScheduler

remove a job with the matching jobId

Specified by:

remove in interface JobScheduler

Parameters:

jobId - The unique Job Id to search for and remove from the scheduled set of jobs.

Throws:

IOException

removeAllJobs

public void removeAllJobs()
                   throws IOException

Description copied from interface: JobScheduler

remove all the Jobs from the scheduler

Specified by:

removeAllJobs in interface JobScheduler

Throws:

IOException

removeAllJobs

public void removeAllJobs(long start,
                          long finish)
                   throws IOException

Description copied from interface: JobScheduler

remove all the Jobs from the scheduler that are due between the start and finish times

Specified by:

removeAllJobs in interface JobScheduler

Parameters:

start - time in milliseconds

finish - time in milliseconds

Throws:

IOException

getNextScheduleTime

public long getNextScheduleTime()
                         throws IOException

Description copied from interface: JobScheduler

Get the next time jobs will be fired

Specified by:

getNextScheduleTime in interface JobScheduler

Returns:

the time in milliseconds

Throws:

IOException

getNextScheduleJobs

public List<Job> getNextScheduleJobs()
                              throws IOException

Description copied from interface: JobScheduler

Get all the jobs scheduled to run next

Specified by:

getNextScheduleJobs in interface JobScheduler

Returns:

a list of jobs that will be scheduled next

Throws:

IOException

getAllJobs

public List<Job> getAllJobs()
                     throws IOException

Description copied from interface: JobScheduler

Get all the outstanding Jobs

Specified by:

getAllJobs in interface JobScheduler

Returns:

a list of all jobs

Throws:

IOException

getAllJobs

public List<Job> getAllJobs(long start,
                            long finish)
                     throws IOException

Description copied from interface: JobScheduler

Get all outstanding jobs due to run between start and finish

Specified by:

getAllJobs in interface JobScheduler

Returns:

a list of jobs

Throws:

IOException

process

protected void process(Transaction tx,
                       KahaAddScheduledJobCommand command,
                       Location location)
                throws IOException

Adds a new Scheduled job to the index. Must be called under index lock. This method must ensure that a duplicate add is not processed into the scheduler. On index recover some adds may be replayed and we don't allow more than one instance of a JobId to exist at any given scheduled time, so filter these out to ensure idempotence.

Parameters:

tx - Transaction in which the update is performed.

command - The new scheduled job command to process.

location - The location where the add command is stored in the journal.

Throws:

IOException - if an error occurs updating the index.

process

protected void process(Transaction tx,
                       KahaRescheduleJobCommand command,
                       Location location)
                throws IOException

Reschedules a Job after it has be fired. For jobs that are repeating this method updates the job in the index by adding it to the jobs list for the new execution time. If the job is not a cron type job then this method will reduce the repeat counter if the job has a fixed number of repeats set. The Job will be removed from the jobs list it just executed on. This method must also update the value of the last update location in the JobLocation instance so that the checkpoint worker doesn't drop the log file in which that command lives. This method must ensure that an reschedule command that references a job that doesn't exist does not cause an error since it's possible that on recover the original add might be gone and so the job should not reappear in the scheduler.

Parameters:

tx - The TX under which the index is updated.

command - The reschedule command to process.

location - The location in the index where the reschedule command was stored.

Throws:

IOException - if an error occurs during the reschedule.

process

protected void process(Transaction tx,
                       KahaRemoveScheduledJobsCommand command,
                       Location location)
                throws IOException

Removes all scheduled jobs within a given time range. The method can be used to clear the entire scheduler index by specifying a range that encompasses all time [0...Long.MAX_VALUE] or a single execution time can be removed by setting start and end time to the same value.

Parameters:

tx - The transaction under which the index is updated.

command - The remove command to process.

location - The location of the remove command in the Journal.

Throws:

IOException - if an error occurs while updating the scheduler index.

removeAll

protected void removeAll(Transaction tx)
                  throws IOException

Removes all jobs from the schedulers index. Must be called with the index locked.

Parameters:

tx - The transaction under which the index entries for this scheduler are removed.

Throws:

IOException - if an error occurs removing the jobs from the scheduler index.

removeInRange

protected void removeInRange(Transaction tx,
                             long start,
                             long finish,
                             Location location)
                      throws IOException

Removes all scheduled jobs within the target range. This method can be used to remove all the stored jobs by passing a range of [0...Long.MAX_VALUE] or it can be used to remove all jobs at a given scheduled time by passing the same time value for both start and end. If the optional location parameter is set then this method will update the store's remove location tracker with the location value and the Jobs that are being removed. This method must be called with the store index locked for writes.

Parameters:

tx - The transaction under which the index is to be updated.

start - The start time for the remove operation.

finish - The end time for the remove operation.

location - (optional) The location of the remove command that triggered this remove.

Throws:

IOException - if an error occurs during the remove operation.

removeJobAtTime

protected boolean removeJobAtTime(Transaction tx,
                                  String jobId,
                                  long executionTime)
                           throws IOException

Removes a Job from the index using it's Id value and the time it is currently set to be executed. This method will only remove the Job if it is found at the given execution time. This method must be called under index lock.

Parameters:

tx - the transaction under which this method is being executed.

jobId - the target Job Id to remove.

executionTime - the scheduled time that for the Job Id that is being removed.

Throws:

IOException - if an error occurs while removing the Job.

getAllScheduledJobs

protected List<org.apache.activemq.store.kahadb.scheduler.JobLocation> getAllScheduledJobs(Transaction tx)
                                                                                    throws IOException

Walks the Scheduled Job Tree and collects the add location and last update location for all scheduled jobs. This method must be called with the index locked.

Parameters:

tx - the transaction under which this operation was invoked.

Returns:

a list of all referenced Location values for this JobSchedulerImpl

Throws:

IOException - if an error occurs walking the scheduler tree.

run

public void run()

Specified by:

run in interface Runnable

toString

public String toString()

Overrides:

toString in class Object

mainLoop

protected void mainLoop()

startDispatching

public void startDispatching()
                      throws Exception

Description copied from interface: JobScheduler

Starts dispatch of scheduled Jobs to registered listeners. Any listener added after the start dispatch method can miss jobs so its important to register critical listeners before the start of job dispatching.

Specified by:

startDispatching in interface JobScheduler

Throws:

Exception

stopDispatching

public void stopDispatching()
                     throws Exception

Description copied from interface: JobScheduler

Stops dispatching of scheduled Jobs to registered listeners.

Specified by:

stopDispatching in interface JobScheduler

Throws:

Exception

doStart

protected void doStart()
                throws Exception

Specified by:

doStart in class ServiceSupport

Throws:

Exception

doStop

protected void doStop(ServiceStopper stopper)
               throws Exception

Specified by:

doStop in class ServiceSupport

Throws:

Exception

write

public void write(DataOutput out)
           throws IOException

Throws:

IOException