Rajesh Balamohan created TEZ-1911:
-------------------------------------
Summary: MergeManager's unconditionalReserve() should check for
memory limits before allocating memory to IntermediateMemoryToMemoryMerger
Key: TEZ-1911
URL: https://issues.apache.org/jira/browse/TEZ-1911
Project: Apache Tez
Issue Type: Bug
Reporter: Rajesh Balamohan
Currently, IntermediateMemoryToMemoryMerger invokes unconditionalReserve() to
get the memory needed for intermediate mem-to-mem merging. It could
potentially cause issue in the following scenario
1. tez.runtime.io.sort.factor set to 100 and assume shuffled data (e.g 60%
memory occupied) haven't reached TEZ_RUNTIME_SHUFFLE_MERGE_PERCENT_DEFAULT
2. Assume that it reaches the sort.factor threshold before reaching merge
threshold. This would kick in IntermediateMemoryToMemoryMerger.
In IntermediateMemoryToMemoryMerger, it would try to allocate additional 60%
without any boundary checks. This could lead to OOM depending on the
tez.runtime.io.sort.mb setting.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
