[HDDS-7304] EC: EC Decode can fail when byteBuffer from elastic pool is larger than chunksize

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0
• Component/s: EC Client
• Labels: pull-request-available
• Assignee: Stephen O'Donnell
• Reporter: Stephen O'Donnell
• Created: 10/Oct/22 15:41
• Updated: 11/Oct/22 09:48
• Resolved: 11/Oct/22 09:48

Description

The EC client establishes an ElasticByteBufferPool, so that byte buffers can be assigned / freed and reused without allocating and freeing memory over and over. The buffer returned by the elastic buffer can be larger than the size requested, and if that is the case we can get an error on EC decode, such as:

java.lang.IllegalArgumentException: Invalid buffer [3], not of length 1048576

	at org.apache.ozone.erasurecode.rawcoder.ByteBufferDecodingState.checkInputBuffers(ByteBufferDecodingState.java:106)
	at org.apache.ozone.erasurecode.rawcoder.ByteBufferDecodingState.<init>(ByteBufferDecodingState.java:44)
	at org.apache.ozone.erasurecode.rawcoder.RawErasureDecoder.decode(RawErasureDecoder.java:84)
	at org.apache.hadoop.ozone.client.io.ECBlockReconstructedStripeInputStream.decodeStripe(ECBlockReconstructedStripeInputStream.java:649)
	at org.apache.hadoop.ozone.client.io.ECBlockReconstructedStripeInputStream.read(ECBlockReconstructedStripeInputStream.java:388)
	at org.apache.hadoop.ozone.client.io.TestECBlockReconstructedStripeInputStream.testErrorReadingBlockContinuesReading(TestECBlockReconstructedStripeInputStream.java:622)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:725)
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
...

The solution is to set the limit on the buffer to the appropriate size before attempting to use it.

Issue Links

• links to: GitHub Pull Request #3817