Java high CPU due to concurrent HashMap access in Apache Axis TypeMappingImpl.internalRegister

Environment

• JBoss Enterprise Application Platform (EAP)
• Apache Axis

Issue

• We are seeing high CPU due to multiple threads accessing the same HashMap at once in Apache Axis TypeMappingImpl, for example:

Thread: http-0.0.0.0-8080-5 state=runnable
	java.util.HashMap.put
	org.apache.axis.encoding.TypeMappingImpl.internalRegister
	org.apache.axis.encoding.TypeMappingImpl.register
	org.apache.axis.encoding.TypeMappingDelegate.register
	org.apache.axis.client.Call.registerTypeMapping
	org.apache.axis.client.Call.registerTypeMapping

Resolution

• Await a fix to Apache Axis
• Red Hat does not support Apache Axis; you can consider migrating to a supported web service stack instead.
• You could consider adding synchronization lower in the application layer to try to prevent the improper concurrency at the Axis layer.

Root Cause

• Concurrent access to a single HashMap can cause high cpu loops per High CPU due to multiple Java threads accessing HashMap simultaneously
• This results from an Apache Axis bug allowing HashMap access that is not thread safe:
  • Content from issues.apache.org is not included.AXIS-2792
  • Content from issues.apache.org is not included.AXIS-2498

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