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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65680/
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(Updated Feb. 16, 2018, 6:45 p.m.)
Review request for Aurora, David McLaughlin, Renan DelValle, and Santhosh Kumar
Shanmugham.
Changes
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Remove unused imports
Repository: aurora
Description
-------
There is a pretty rare situation that can occur that will cause the scheduler
to crash.
Stacktrace:
```
Feb 16, 2018 12:22:36 AM
com.google.common.util.concurrent.ServiceManager$ServiceListener failed
SEVERE: Service CronBatchWorker [FAILED] has failed in the RUNNING state.
java.lang.IllegalArgumentException: Instance ID collision detected.
at
org.apache.aurora.scheduler.state.StateManagerImpl.insertPendingTasks(StateManagerImpl.java:126)
at
org.apache.aurora.scheduler.cron.quartz.AuroraCronJob.lambda$null$0(AuroraCronJob.java:213)
at
org.apache.aurora.scheduler.BatchWorker.lambda$processBatch$3(BatchWorker.java:210)
at
org.apache.aurora.scheduler.storage.Storage$MutateWork$NoResult.apply(Storage.java:144)
at
org.apache.aurora.scheduler.storage.Storage$MutateWork$NoResult.apply(Storage.java:139)
at
org.apache.aurora.scheduler.storage.durability.DurableStorage.lambda$doInTransaction$0(DurableStorage.java:199)
at
org.apache.aurora.scheduler.storage.mem.MemStorage.write(MemStorage.java:89)
at
org.apache.aurora.common.inject.TimedInterceptor.invoke(TimedInterceptor.java:83)
at
org.apache.aurora.scheduler.storage.durability.DurableStorage.doInTransaction(DurableStorage.java:198)
at
org.apache.aurora.scheduler.storage.durability.DurableStorage.write(DurableStorage.java:221)
at
org.apache.aurora.scheduler.storage.CallOrderEnforcingStorage.write(CallOrderEnforcingStorage.java:132)
at
org.apache.aurora.scheduler.BatchWorker.processBatch(BatchWorker.java:207)
at org.apache.aurora.scheduler.BatchWorker.run(BatchWorker.java:199)
at
com.google.common.util.concurrent.AbstractExecutionThreadService$1$2.run(AbstractExecutionThreadService.java:66)
at com.google.common.util.concurrent.Callables$4.run(Callables.java:122)
at java.lang.Thread.run(Thread.java:748)
```
The steps are:
```
1. Schedule and start a cron (runs every minute, graceful shutdown period > 1
minute)
2. Perform 2 runs of the cron
3. Deschedule the cron
4. Reschedule the cron
5. Perform 3 runs of the cron
6. Scheduler will crash on the 3rd run due to an ID collision between the
already running cron and a new cron trying to start
```
The reason for this bug is that some state is persisted between cron
scheduling/descheduling via `killFollowups`. We use Quartz `JobDataMap` to hold
a "work in progress" token, while the `killFollowups` set indicates
"completion" in order to ensure there are no concurrent runs. Descheduling a
cron will remove the "work in progress" token while ignoring the "completion"
token in `killFollowups`. Later, a "work in progress" token may be added and a
"completion" token may be seen mistakenly from a previous schedule, causing a
concurrent run.
For the example above, the runs in step 2 will add the key to the set to show
that all runs are finished and another run can start. The 3rd run in step 5
will mistakenly see that the 2nd run has started and finished since the
"completion" token was preserved from the first set of runs in step 2. This
will erroneously trigger a concurrent run causing a ID collision.
We should not preserve any state between cron scheduling/descheduling outside
of the given Quartz `JobDataMap` abstraction. We can use the presence of a
value here to achieve the same thing as `killFollowups`.
Diffs (updated)
-----
src/main/java/org/apache/aurora/scheduler/cron/quartz/AuroraCronJob.java
3604dd4c84043def3fe098ca0f87bf8bab99b3db
src/test/java/org/apache/aurora/scheduler/cron/quartz/AuroraCronJobTest.java
5083fcd407a069617634b82db1ad799b5d4d4551
Diff: https://reviews.apache.org/r/65680/diff/2/
Changes: https://reviews.apache.org/r/65680/diff/1-2/
Testing
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Repro'd bug using steps above. Validated code changes solved issue.
Added small change in unit test to ensure state is now preserved in the Quartz
job context.
`./gradlew test`
Thanks,
Jordan Ly
