[YARN-2387] Resource Manager crashes with NPE due to lack of synchronization

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.5.0, 3.0.0-alpha1
• Fix Version/s: 2.6.0
• Target Version/s: 2.6.0
• Hadoop Flags: Reviewed
• Assignee: Mit Desai
• Reporter: Mit Desai
• Created: 06/Aug/14 19:06
• Updated: 12/May/16 18:30
• Resolved: 30/Sep/14 22:45

Description

We recently came across a 0.23 RM crashing with an NPE. Here is the stacktrace for it.

2014-08-06 05:56:52,165 [ResourceManager Event Processor] FATAL
org.apache.hadoop.yarn.server.resourcemanager.ResourceManager: Error in
handling event type NODE_UPDATE to the scheduler
java.lang.NullPointerException
        at
org.apache.hadoop.yarn.api.records.impl.pb.ContainerStatusPBImpl.mergeLocalToBuilder(ContainerStatusPBImpl.java:61)
        at
org.apache.hadoop.yarn.api.records.impl.pb.ContainerStatusPBImpl.mergeLocalToProto(ContainerStatusPBImpl.java:68)
        at
org.apache.hadoop.yarn.api.records.impl.pb.ContainerStatusPBImpl.getProto(ContainerStatusPBImpl.java:53)
        at
org.apache.hadoop.yarn.api.records.impl.pb.ContainerStatusPBImpl.getProto(ContainerStatusPBImpl.java:34)
        at
org.apache.hadoop.yarn.api.records.ProtoBase.toString(ProtoBase.java:55)
        at java.lang.String.valueOf(String.java:2854)
        at java.lang.StringBuilder.append(StringBuilder.java:128)
        at
org.apache.hadoop.yarn.api.records.impl.pb.ContainerPBImpl.toString(ContainerPBImpl.java:353)
        at java.lang.String.valueOf(String.java:2854)
        at java.lang.StringBuilder.append(StringBuilder.java:128)
        at
org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.LeafQueue.completedContainer(LeafQueue.java:1405)
        at
org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.completedContainer(CapacityScheduler.java:790)
        at
org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.nodeUpdate(CapacityScheduler.java:602)
        at
org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.handle(CapacityScheduler.java:688)
        at
org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.handle(CapacityScheduler.java:82)
        at
org.apache.hadoop.yarn.server.resourcemanager.ResourceManager$SchedulerEventDispatcher$EventProcessor.run(ResourceManager.java:339)
        at java.lang.Thread.run(Thread.java:722)
2014-08-06 05:56:52,166 [ResourceManager Event Processor] INFO
org.apache.hadoop.yarn.server.resourcemanager.ResourceManager: Exiting, bbye..

On investigating a on the issue we found that the ContainerStatusPBImpl has methods that are called by different threads and are not synchronized. Even the 2.X code looks alike.

We need to make these methods synchronized so that we do not encounter this problem in future.