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AMQ-9808: Dead lock when using CRON schedule with AMQ_SCHEDULED_REPEAT #1536

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AMQ-9808: Dead lock when using CRON schedule with AMQ_SCHEDULED_REPEAT #1536

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AMQ-9808: Dead lock when using CRON schedule with AMQ_SCHEDULED_REPEAT
jeanouii Nov 17, 2025
199b69b
AMQ-9808: Consistency and better exception handling
jeanouii Nov 18, 2025
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34 changes: 28 additions & 6 deletions ...hadb-store/src/main/java/org/apache/activemq/store/kahadb/scheduler/JobSchedulerImpl.java
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Original file line number Diff line number Diff line change
Expand Up @@ -268,6 +268,16 @@ private void doReschedule(final String jobId, long executionTime, long nextExecu
this.store.store(update);
}

private void doSchedule(final List<Closure> toSchedule) {
for (Closure closure : toSchedule) {
try {
closure.run();
} catch (final Exception e) {
LOG.warn("Failed to schedule job", e);
}
}
}

private void doRemove(final List<Closure> toRemove) throws IOException {
for (Closure closure : toRemove) {
closure.run();
Expand Down Expand Up @@ -727,6 +737,7 @@ protected void mainLoop() {
// needed before firing the job event.
List<Closure> toRemove = new ArrayList<>();
List<Closure> toReschedule = new ArrayList<>();
List<Closure> toSchedule = new ArrayList<>();
try {
this.store.readLockIndex();

Expand Down Expand Up @@ -776,12 +787,18 @@ protected void mainLoop() {
// we have a separate schedule to run at this time
// so the cron job is used to set of a separate schedule
// hence we won't fire the original cron job to the
// listeners but we do need to start a separate schedule
String jobId = ID_GENERATOR.generateId();
ByteSequence payload = getPayload(job.getLocation());
schedule(jobId, payload, "", job.getDelay(), job.getPeriod(), job.getRepeat());
waitTime = job.getDelay() != 0 ? job.getDelay() : job.getPeriod();
this.scheduleTime.setWaitTime(waitTime);
// listeners, but we do need to start a separate schedule
toSchedule.add(() -> {
try {
String jobId = ID_GENERATOR.generateId();
ByteSequence payload = getPayload(job.getLocation());
schedule(jobId, payload, "", job.getDelay(), job.getPeriod(), job.getRepeat());
} catch (Exception e) {
LOG.warn("Failed to schedule cron follow-up job", e);
}
});
long wait = job.getDelay() != 0 ? job.getDelay() : job.getPeriod();
this.scheduleTime.setWaitTime(wait);
}
} else {
toRemove.add(() -> doRemove(executionTime, job.getJobId()));
Expand All @@ -797,6 +814,10 @@ protected void mainLoop() {
} finally {
this.store.readUnlockIndex();

// deferred execution of all jobs to be scheduled to avoid deadlock with indexLock
doSchedule(toSchedule);

// now reschedule all jobs that need rescheduling
doReschedule(toReschedule);

// now remove all jobs that have not been rescheduled,
Expand All @@ -805,6 +826,7 @@ protected void mainLoop() {
}

this.scheduleTime.pause();

} catch (Exception ioe) {
LOG.error("{} Failed to schedule job", this.name, ioe);
try {
Expand Down
22 changes: 13 additions & 9 deletions activemq-unit-tests/src/test/java/org/apache/activemq/broker/scheduler/JmsSchedulerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -16,14 +16,6 @@
*/
package org.apache.activemq.broker.scheduler;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;

import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import jakarta.jms.Connection;
import jakarta.jms.JMSException;
import jakarta.jms.Message;
Expand All @@ -32,7 +24,6 @@
import jakarta.jms.MessageProducer;
import jakarta.jms.Session;
import jakarta.jms.TextMessage;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.ScheduledMessage;
import org.apache.activemq.store.kahadb.disk.journal.Location;
Expand All @@ -48,6 +39,14 @@
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;

public class JmsSchedulerTest extends JobSchedulerTestSupport {

private static final Logger LOG = LoggerFactory.getLogger(JmsSchedulerTest.class);
Expand Down Expand Up @@ -230,6 +229,11 @@ public void append(LogEvent event) {
numberOfDiscardedJobs.incrementAndGet();
}
}

@Override
public boolean isStarted() {
return true; // false in DefaultTestAppender so Log4j will discard this appender
}
};

registerLogAppender(appender);
Expand Down