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https://issues.apache.org/jira/browse/HBASE-12728?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14283266#comment-14283266
]
Hadoop QA commented on HBASE-12728:
-----------------------------------
{color:red}-1 overall{color}. Here are the results of testing the latest
attachment
http://issues.apache.org/jira/secure/attachment/12693172/HBASE-12728-3.patch
against master branch at commit 53815afc1023a624d6b6069f4111692951a78848.
ATTACHMENT ID: 12693172
{color:green}+1 @author{color}. The patch does not contain any @author
tags.
{color:green}+1 tests included{color}. The patch appears to include 99 new
or modified tests.
{color:green}+1 javac{color}. The applied patch does not increase the
total number of javac compiler warnings.
{color:green}+1 javac{color}. The applied patch does not increase the
total number of javac compiler warnings.
{color:red}-1 javadoc{color}. The javadoc tool appears to have generated 3
warning messages.
{color:red}-1 checkstyle{color}. The applied patch generated
2084 checkstyle errors (more than the master's current 2073 errors).
{color:green}+1 findbugs{color}. The patch does not introduce any new
Findbugs (version 2.0.3) warnings.
{color:green}+1 release audit{color}. The applied patch does not increase
the total number of release audit warnings.
{color:red}-1 lineLengths{color}. The patch introduces the following lines
longer than 100:
+ * <p>BufferedMutator can also be used on more exotic circumstances.
Map/Reduce batch jobs will have a
+ * single BufferedMutator per thread. A single BufferedMutator can also be
effectively used in high volume
+ private void doMutate(Mutation m) throws InterruptedIOException,
RetriesExhaustedWithDetailsException {
+ * This is used for legacy purposes in {@link HTable} only. This ought not
be called for production
+ * An implementation of {@link Lock} that doesn't actually lock anything.
{@link BufferedMutatorImpl} uses
+ public static void loadData(final HBaseTestingUtility util, final
BufferedMutator mutator, int rows,
{color:green}+1 site{color}. The mvn site goal succeeds with this patch.
{color:green}+1 core tests{color}. The patch passed unit tests in .
Test results:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//testReport/
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-rest.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-common.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-client.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-annotations.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-hadoop-compat.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-server.html
Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-prefix-tree.html
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Findbugs warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/newPatchFindbugsWarningshbase-thrift.html
Findbugs warnings:
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Findbugs warnings:
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Checkstyle Errors:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/checkstyle-aggregate.html
Javadoc warnings:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//artifact/patchprocess/patchJavadocWarnings.txt
Console output:
https://builds.apache.org/job/PreCommit-HBASE-Build/12512//console
This message is automatically generated.
> buffered writes substantially less useful after removal of HTablePool
> ---------------------------------------------------------------------
>
> Key: HBASE-12728
> URL: https://issues.apache.org/jira/browse/HBASE-12728
> Project: HBase
> Issue Type: Bug
> Components: hbase
> Affects Versions: 0.98.0
> Reporter: Aaron Beppu
> Assignee: Nick Dimiduk
> Priority: Blocker
> Fix For: 1.0.0, 2.0.0, 1.1.0
>
> Attachments: 12728.connection-owns-buffers.example.branch-1.0.patch,
> HBASE-12728-2.patch, HBASE-12728-3.patch, HBASE-12728.patch,
> bulk-mutator.patch
>
>
> In previous versions of HBase, when use of HTablePool was encouraged, HTable
> instances were long-lived in that pool, and for that reason, if autoFlush was
> set to false, the table instance could accumulate a full buffer of writes
> before a flush was triggered. Writes from the client to the cluster could
> then be substantially larger and less frequent than without buffering.
> However, when HTablePool was deprecated, the primary justification seems to
> have been that creating HTable instances is cheap, so long as the connection
> and executor service being passed to it are pre-provided. A use pattern was
> encouraged where users should create a new HTable instance for every
> operation, using an existing connection and executor service, and then close
> the table. In this pattern, buffered writes are substantially less useful;
> writes are as small and as frequent as they would have been with
> autoflush=true, except the synchronous write is moved from the operation
> itself to the table close call which immediately follows.
> More concretely :
> ```
> // Given these two helpers ...
> private HTableInterface getAutoFlushTable(String tableName) throws
> IOException {
> // (autoflush is true by default)
> return storedConnection.getTable(tableName, executorService);
> }
> private HTableInterface getBufferedTable(String tableName) throws IOException
> {
> HTableInterface table = getAutoFlushTable(tableName);
> table.setAutoFlush(false);
> return table;
> }
> // it's my contention that these two methods would behave almost identically,
> // except the first will hit a synchronous flush during the put call,
> and the second will
> // flush during the (hidden) close call on table.
> private void writeAutoFlushed(Put somePut) throws IOException {
> try (HTableInterface table = getAutoFlushTable(tableName)) {
> table.put(somePut); // will do synchronous flush
> }
> }
> private void writeBuffered(Put somePut) throws IOException {
> try (HTableInterface table = getBufferedTable(tableName)) {
> table.put(somePut);
> } // auto-close will trigger synchronous flush
> }
> ```
> For buffered writes to actually provide a performance benefit to users, one
> of two things must happen:
> - The writeBuffer itself shouldn't live, flush and die with the lifecycle of
> it's HTableInstance. If the writeBuffer were managed elsewhere and had a long
> lifespan, this could cease to be an issue. However, if the same writeBuffer
> is appended to by multiple tables, then some additional concurrency control
> will be needed around it.
> - Alternatively, there should be some pattern for having long-lived HTable
> instances. However, since HTable is not thread-safe, we'd need multiple
> instances, and a mechanism for leasing them out safely -- which sure sounds a
> lot like the old HTablePool to me.
> See discussion on mailing list here :
> http://mail-archives.apache.org/mod_mbox/hbase-user/201412.mbox/%3CCAPdJLkEzmUQZ_kvD%3D8mrxi4V%3DhCmUp3g9MUZsddD%2Bmon%2BAvNtg%40mail.gmail.com%3E
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