[
https://issues.apache.org/jira/browse/CRUNCH-346?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13902765#comment-13902765
]
Gabriel Reid commented on CRUNCH-346:
-------------------------------------
Ok, I'll put together a patch for this.
About the fact that the correct primitive handling is only done for Avro --
there's no technical reason for this, as far as I'm aware. Instead, it's just
that the the short-circuiting to a no-op for the deep-copying was never done
for Writables. All of your understanding of the deep-copying is correct as you
described it.
> Don't deep-copy immutable Writable PTypes
> -----------------------------------------
>
> Key: CRUNCH-346
> URL: https://issues.apache.org/jira/browse/CRUNCH-346
> Project: Crunch
> Issue Type: Improvement
> Reporter: Chao Shi
>
> I found getDetachedValue() appears quite often when jstack on one of my
> pipeline. A piece of stacktrace is shown below. In the pipeline, most of
> types we used are immutable (e.g. java primitives, strings, protobuf). I
> think we can avoid deep-copy overhead here.
> "main" prio=10 tid=0x00007f0de801d800 nid=0x7ef runnable [0x00007f0dee66c000]
> java.lang.Thread.State: RUNNABLE
> at org.apache.hadoop.io.BytesWritable.<init>(BytesWritable.java:52)
> at org.apache.hadoop.io.BytesWritable.<init>(BytesWritable.java:46)
> at sun.reflect.GeneratedConstructorAccessor9.newInstance(Unknown Source)
> at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
> at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
> at java.lang.Class.newInstance0(Class.java:355)
> at java.lang.Class.newInstance(Class.java:308)
> at
> org.apache.crunch.types.writable.WritableDeepCopier.deepCopy(WritableDeepCopier.java:63)
> at
> org.apache.crunch.types.writable.WritableDeepCopier.deepCopy(WritableDeepCopier.java:36)
> at
> org.apache.crunch.types.writable.WritableType.getDetachedValue(WritableType.java:125)
> at
> org.apache.crunch.impl.mr.emit.IntermediateEmitter.emit(IntermediateEmitter.java:54)
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
