Kevin Wilfong created HIVE-3302:
-----------------------------------
Summary: Race condition in query plan for merging at the end of a
query
Key: HIVE-3302
URL: https://issues.apache.org/jira/browse/HIVE-3302
Project: Hive
Issue Type: Bug
Components: Query Processor
Affects Versions: 0.10.0
Reporter: Kevin Wilfong
Assignee: Kevin Wilfong
Priority: Critical
In the query plan that's used to merge files at the end of a query, the
dependency tree looks something like:
MoveTask(1)
/ \
...ConditionalTask MoveTask(2)...
\ /
MergeTask
Here MoveTask(1) moves the partition data to a temporary location, and
MoveTask(2) moves it to the final location.
However if there are dynamic partitions generated and some of these partitions
are merged and others are moved, the dependency tree is changed at runtime to:
...ConditionalTask MoveTask(2)...
\ /
MergeTask
\
MoveTask(1)
This produces a race condition between the two MoveTasks where if MoveTask(2)
runs before MoveTask(1) the partitions moved by MoveTask(1) will get moved to
an intermediate location and never moved to the final location. In this case
those partitions are quietly lost.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
