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Kuhu Shukla commented on TEZ-3605: ---------------------------------- bq. and invokes a merger on an empty list (not sure how this is handled) Empty List is handled fine {quote} if (segments.size() == 0) { LOG.info("Nothing to merge. Returning an empty iterator"); return new EmptyIterator(); } {quote} It is when the segment size is zero when it gets into trouble due to a stream with no bytes to read. > Detect and prune empty partitions for the Ordered case > ------------------------------------------------------ > > Key: TEZ-3605 > URL: https://issues.apache.org/jira/browse/TEZ-3605 > Project: Apache Tez > Issue Type: Bug > Reporter: Kuhu Shukla > Assignee: Kuhu Shukla > Attachments: TEZ-3605.001.patch, TEZ-3605.002.patch, > TEZ-3605.003.patch, TEZ-3605.004.patch, TEZ-3605.005.patch, > TEZ-3605.006.patch, TEZ-3605.007.patch, TEZ-3605.008.patch, > TEZ-3605.009.patch, TEZ-3605.010.patch, TEZ-3605.011.patch > > > Analogous to the Unordered case we should not have empty partition > entries/segments in the Ordered/DefaultSorter case. This will save writing > unnecessary data. > Additionally, with tez_shuffle feature (TEZ-3334), in a heavily auto reduced > job, this change would allow not fetching empty partitions and then throwing > them away. -- This message was sent by Atlassian JIRA (v6.4.14#64029)