[AMQ-4683] Scheduler discards overdue messages on startup

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 5.8.0
• Fix Version/s: 5.9.0
• Component/s: Broker
• Labels: scheduler

Environment

Windows 7 64bit, JDK 1.6.0_26

• Assignee: Timothy A. Bish
• Reporter: Andrey Zavodnik
• Created: 14/Aug/13 14:07
• Updated: 04/Oct/13 13:13
• Resolved: 23/Aug/13 16:04

Description

When message is scheduled for a delivery (using AMQ_SCHEDULED_PERIOD property) it is not posted to the queue, but saved to the scheduler’s repository instead. If Broker instance is shut down at the time for which the message is scheduled for a delivery, the scheduler will try to process the message at the next time broker is started up. Due to a bug in the scheduler implementation such messages may be dismissed rather than posted to the queue depending on the racing conditions inside the JVM.

Actual bug resides in org.apache.activemq.broker.scheduler.SchedulerBroker.getInternalScheduler() method.
This method first calls JobSchedulerStoreImpl. getJobScheduler(String name) method which in turn creates an instance of runnable JobSchedulerImpl class and starts it.
Then SchedulerBroker registers itselfas a listener of the newly created JobSchedulerImpl.
Unfortunately this may happen after the JobSchedulerImpl have dismissed all the “missed” tasks as “fired” as there were no listeners configured.

Issue Links

• duplicates: AMQ-4550 Allow messages scheduled for retry by the broker to be sent post-restart if the broker is not running at the jobs scheduled time
• is duplicated by: AMQ-4783 Scheduled messages lost if broker is shut down during the scheduled time of the message
• supercedes: AMQ-4550 Allow messages scheduled for retry by the broker to be sent post-restart if the broker is not running at the jobs scheduled time