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author | zsxwing <zsxwing@gmail.com> | 2015-08-19 19:43:09 -0700 |
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committer | Tathagata Das <tathagata.das1565@gmail.com> | 2015-08-19 19:43:09 -0700 |
commit | affc8a887ede9fdc2ca6051833954cd10918c869 (patch) | |
tree | bbab7e39e672cdb8ff8a9e61b75a73af1aaf7a9e | |
parent | 1f29d502e7ecd6faa185d70dc714f9ea3922fb6d (diff) | |
download | spark-affc8a887ede9fdc2ca6051833954cd10918c869.tar.gz spark-affc8a887ede9fdc2ca6051833954cd10918c869.tar.bz2 spark-affc8a887ede9fdc2ca6051833954cd10918c869.zip |
[SPARK-10125] [STREAMING] Fix a potential deadlock in JobGenerator.stop
Because `lazy val` uses `this` lock, if JobGenerator.stop and JobGenerator.doCheckpoint (JobGenerator.shouldCheckpoint has not yet been initialized) run at the same time, it may hang.
Here are the stack traces for the deadlock:
```Java
"pool-1-thread-1-ScalaTest-running-StreamingListenerSuite" #11 prio=5 os_prio=31 tid=0x00007fd35d094800 nid=0x5703 in Object.wait() [0x000000012ecaf000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Thread.join(Thread.java:1245)
- locked <0x00000007b5d8d7f8> (a org.apache.spark.util.EventLoop$$anon$1)
at java.lang.Thread.join(Thread.java:1319)
at org.apache.spark.util.EventLoop.stop(EventLoop.scala:81)
at org.apache.spark.streaming.scheduler.JobGenerator.stop(JobGenerator.scala:155)
- locked <0x00000007b5d8cea0> (a org.apache.spark.streaming.scheduler.JobGenerator)
at org.apache.spark.streaming.scheduler.JobScheduler.stop(JobScheduler.scala:95)
- locked <0x00000007b5d8ced8> (a org.apache.spark.streaming.scheduler.JobScheduler)
at org.apache.spark.streaming.StreamingContext.stop(StreamingContext.scala:687)
"JobGenerator" #67 daemon prio=5 os_prio=31 tid=0x00007fd35c3b9800 nid=0x9f03 waiting for monitor entry [0x0000000139e4a000]
java.lang.Thread.State: BLOCKED (on object monitor)
at org.apache.spark.streaming.scheduler.JobGenerator.shouldCheckpoint$lzycompute(JobGenerator.scala:63)
- waiting to lock <0x00000007b5d8cea0> (a org.apache.spark.streaming.scheduler.JobGenerator)
at org.apache.spark.streaming.scheduler.JobGenerator.shouldCheckpoint(JobGenerator.scala:63)
at org.apache.spark.streaming.scheduler.JobGenerator.doCheckpoint(JobGenerator.scala:290)
at org.apache.spark.streaming.scheduler.JobGenerator.org$apache$spark$streaming$scheduler$JobGenerator$$processEvent(JobGenerator.scala:182)
at org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:83)
at org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:82)
at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
```
I can use this patch to produce this deadlock: https://github.com/zsxwing/spark/commit/8a88f28d1331003a65fabef48ae3d22a7c21f05f
And a timeout build in Jenkins due to this deadlock: https://amplab.cs.berkeley.edu/jenkins/job/NewSparkPullRequestBuilder/1654/
This PR initializes `checkpointWriter` before `eventLoop` uses it to avoid this deadlock.
Author: zsxwing <zsxwing@gmail.com>
Closes #8326 from zsxwing/SPARK-10125.
-rw-r--r-- | streaming/src/main/scala/org/apache/spark/streaming/scheduler/JobGenerator.scala | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/scheduler/JobGenerator.scala b/streaming/src/main/scala/org/apache/spark/streaming/scheduler/JobGenerator.scala index 9f2117ada6..2de035d166 100644 --- a/streaming/src/main/scala/org/apache/spark/streaming/scheduler/JobGenerator.scala +++ b/streaming/src/main/scala/org/apache/spark/streaming/scheduler/JobGenerator.scala @@ -79,6 +79,10 @@ class JobGenerator(jobScheduler: JobScheduler) extends Logging { def start(): Unit = synchronized { if (eventLoop != null) return // generator has already been started + // Call checkpointWriter here to initialize it before eventLoop uses it to avoid a deadlock. + // See SPARK-10125 + checkpointWriter + eventLoop = new EventLoop[JobGeneratorEvent]("JobGenerator") { override protected def onReceive(event: JobGeneratorEvent): Unit = processEvent(event) |