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https://issues.apache.org/jira/browse/HBASE-10584?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13909293#comment-13909293
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Hadoop QA commented on HBASE-10584:
-----------------------------------
{color:red}-1 overall{color}. Here are the results of testing the latest
attachment
http://issues.apache.org/jira/secure/attachment/12630288/HBASE-10584-trunk_v1.patch
against trunk revision .
ATTACHMENT ID: 12630288
{color:green}+1 @author{color}. The patch does not contain any @author
tags.
{color:red}-1 tests included{color}. The patch doesn't appear to include
any new or modified tests.
Please justify why no new tests are needed for this
patch.
Also please list what manual steps were performed to
verify this patch.
{color:green}+1 hadoop1.0{color}. The patch compiles against the hadoop
1.0 profile.
{color:green}+1 hadoop1.1{color}. The patch compiles against the hadoop
1.1 profile.
{color:green}+1 javadoc{color}. The javadoc tool did not generate any
warning messages.
{color:green}+1 javac{color}. The applied patch does not increase the
total number of javac compiler warnings.
{color:green}+1 findbugs{color}. The patch does not introduce any new
Findbugs (version 1.3.9) warnings.
{color:green}+1 release audit{color}. The applied patch does not increase
the total number of release audit warnings.
{color:green}+1 lineLengths{color}. The patch does not introduce lines
longer than 100
{color:green}+1 site{color}. The mvn site goal succeeds with this patch.
{color:red}-1 core tests{color}. The patch failed these unit tests:
org.apache.hadoop.hbase.util.TestHBaseFsck
Test results:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//testReport/
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-protocol.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-thrift.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-client.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-hadoop2-compat.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-examples.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-prefix-tree.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-common.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-server.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-hadoop-compat.html
Console output:
https://builds.apache.org/job/PreCommit-HBASE-Build/8774//console
This message is automatically generated.
> Inconsistency between tableExists and listTables in implementation
> ------------------------------------------------------------------
>
> Key: HBASE-10584
> URL: https://issues.apache.org/jira/browse/HBASE-10584
> Project: HBase
> Issue Type: Bug
> Components: Client, master
> Reporter: Feng Honghua
> Assignee: Feng Honghua
> Attachments: HBASE-10584-trunk_v1.patch
>
>
> # HBaseAdmin.tableExists is implemented by scanning meta table
> # HBaseAdmin.listTables(and HBaseAdmin.getTableDescriptor) is implemented by
> talking with HMaster which responses by querying the FSTableDescriptors, and
> FSTableDescriptors return all tables by scanning all the table descriptor
> files in FS(cache also plays here, so most of time it can be satisfied by
> cache)...
> Actually HBaseAdmin requests HMaster to check if a table exists internally
> when implementing deleteTable(see below), then why does it use a
> different(scanning meta table) way to implementing tableExists() for outside
> user to use for the same purpose?
> {code}
> tableExists = false;
> GetTableDescriptorsResponse htds;
> MasterKeepAliveConnection master = connection.getKeepAliveMasterService();
> try {
> GetTableDescriptorsRequest req =
> RequestConverter.buildGetTableDescriptorsRequest(tableName);
> htds = master.getTableDescriptors(null, req);
> } catch (ServiceException se) {
> throw ProtobufUtil.getRemoteException(se);
> } finally {
> master.close();
> }
> tableExists = !htds.getTableSchemaList().isEmpty();
> {code}
> (Above verifying that table descriptor file is deleted can guarantee all
> items of this table are deleted from meta table...)
> Since creating table descriptor files and inserting item to meta table occur
> in different time without atomic semantic, this inconsistency in
> implementation can lead to confusing behaviors when create-table or
> delete-table fails midway, (before according cleanup is done) table
> descriptor file may exists while no item exists in meta table (for
> create-table where table descriptor file is created before inserting item to
> meta table), this leads to listTables including that table, while tableExists
> says no. Similar inconsistency if delete-table fails mid-way...
> Confusing behavior can happen during the process even though eventually it
> succeed:
> # During table creation, when a user calls listTables and then calls
> tableExists for this table after the table descriptor is created but before
> item is inserted to meta table. He will find the listTables includes a table
> but tableExists return false for that same table, this behavior is confusing
> and should only acceptable during the table is being deleted...
> # Similar behavior occurs during table deletion.
> Seems the benefit of implementing tableExists this way is we can avoid
> talking with HMaster, considering we talk with HMaster for listTables and
> getTableDescriptor, such benefit can't offset the drawback from inconsistency.
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