Hello Paul Rogers, Fredy Wijaya, Impala Public Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/12428
to look at the new patch set (#8).
Change subject: IMPALA-7961: Avoid adding unmodified objects to DDL response
......................................................................
IMPALA-7961: Avoid adding unmodified objects to DDL response
When a DDL is processed, we typically add the affected (added/removed)
objects to the response TCatalogUpdateResult struct. This response
is processed on the coordinator and the changes are applied locally.
When SYNC_DDL is enabled, the Catalog server also includes a topic
version number that should include all the affected objects so that the
coordinator can wait for that miniumum topic version to be applied on
all other coordinators before returning the control back to the user.
This covering topic version is calculated by looking at the topic
update log, which contains all the in-flight updates (and to an extent
past updates) that are perodically GC'ed.
Bug: In certain cases like CREATE TBL IF NOT EXISTS, we could end up
adding objects to the DDL response which haven't been modified in a
while (> TOPIC_UPDATE_LOG_GC_FREQUENCY) and hence could be potentially
GC'ed from the TopicUpdateLog. This means that the Catalog server
wouldn't be able to find a covering topic update version and eventually
gives up throwing an error as described in the jira.
Fix: Bumps the version of any objects that already exists when IF EXISTS
is used in conjunction with SYNC_DDL. This makes sure that the object is
included in the upcoming topic updates and waitForSyncDdlVersion() can find
a covering topic update that includes this object. This is a hack and could
cause false-positive invalidations, but definitely better than breaking
SYNC_DDL semantics.
Also added some additional diagnostic logging that could've simplified
debugging an issue like this.
Testing: Since this is a racy bug, I could only repro it by forcing
frequent topic update log GCs along with a specific sequence of
actions. Couldn't reproduce it with the patch.
Change-Id: If3e914b70ba796c9b224e9dea559b8c40aa25d83
---
M fe/src/main/java/org/apache/impala/catalog/CatalogServiceCatalog.java
M fe/src/main/java/org/apache/impala/catalog/FeCatalogUtils.java
M fe/src/main/java/org/apache/impala/catalog/TopicUpdateLog.java
M fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java
4 files changed, 92 insertions(+), 31 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/28/12428/8
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: If3e914b70ba796c9b224e9dea559b8c40aa25d83
Gerrit-Change-Number: 12428
Gerrit-PatchSet: 8
Gerrit-Owner: Bharath Vissapragada <bhara...@cloudera.com>
Gerrit-Reviewer: Bharath Vissapragada <bhara...@cloudera.com>
Gerrit-Reviewer: Fredy Wijaya <fwij...@cloudera.com>
Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com>
Gerrit-Reviewer: Paul Rogers <prog...@cloudera.com>
