Vihang Karajgaonkar has uploaded a new patch set (#7). ( http://gerrit.cloudera.org:8080/12789 )
Change subject: IMPALA-8312 : Alter database operations have race condition ...................................................................... IMPALA-8312 : Alter database operations have race condition This patch fixes a race condition in the alter database implementation in the catalogOpExecutor. The original implementation did a in-place modification of the metastore database object in the Db. This can lead to partially updated database object becoming visible to a reading thread causing potential problems. In order to fix the race, the patch makes a copy of the existing database object, modifies the copy and then atomically switches the actual database object with the modified copy. This is done while holding the metastoreddlLock, and then taking the write lock on the catalog version object which makes it consistent with the other catalog write operations. Added a test which consistently reproduces the race. The test creating many reader threads and a writer thread which continuously keeps changing the owner name and its type by issuing a alter database operation. The test fails without the patch. After the patch the test passes. The race also applies to the alter database set comment operation, although its hard to write a test for that code-path. Change-Id: I32c8c96a6029bf9d9db37ea8315f6c9603b5a2fc --- M fe/src/main/java/org/apache/impala/catalog/CatalogServiceCatalog.java M fe/src/main/java/org/apache/impala/catalog/Db.java M fe/src/main/java/org/apache/impala/service/CatalogOpExecutor.java A fe/src/test/java/org/apache/impala/catalog/AlterDatabaseTest.java 4 files changed, 311 insertions(+), 41 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/89/12789/7 -- To view, visit http://gerrit.cloudera.org:8080/12789 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I32c8c96a6029bf9d9db37ea8315f6c9603b5a2fc Gerrit-Change-Number: 12789 Gerrit-PatchSet: 7 Gerrit-Owner: Vihang Karajgaonkar <vih...@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: Vihang Karajgaonkar <vih...@cloudera.com>
