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https://issues.apache.org/jira/browse/HBASE-4241?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13090783#comment-13090783
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jirapos...@reviews.apache.org commented on HBASE-4241:
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Ship it!
Minor comments below. Will wait on your feedback before commit. There is one
thing to fix I think -- the finally thing. Let me know and I can do it on
commit.
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
<https://reviews.apache.org/r/1650/#comment3661>
oh. so we never cared about this before? we'd just keep doing versions
even if well in excess of max? We were pruning versions though? Higher in the
stack? In the scanner that called this one?
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
<https://reviews.apache.org/r/1650/#comment3663>
This is nice, the way you are going to the scanner to next rather than what
we did before where we'd iterate a set.
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
<https://reviews.apache.org/r/1650/#comment3664>
Should this be in a finally block? Would it make a diff if this was left
hanging open because of some exception? We can get one up out of the
scanner.next, right?
oh, there is a finally just after... maybe move the scanner.close in there?
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/CollectionBackedScanner.java
<https://reviews.apache.org/r/1650/#comment3665>
Nice
- Michael
On 2011-08-25 04:49:36, Lars Hofhansl wrote:
bq.
bq. -----------------------------------------------------------
bq. This is an automatically generated e-mail. To reply, visit:
bq. https://reviews.apache.org/r/1650/
bq. -----------------------------------------------------------
bq.
bq. (Updated 2011-08-25 04:49:36)
bq.
bq.
bq. Review request for hbase, Ted Yu, Michael Stack, and Jonathan Gray.
bq.
bq.
bq. Summary
bq. -------
bq.
bq. This avoids flushing row versions to disk that are known to be GC'd by the
next compaction anyway.
bq. This covers two scenarios:
bq. 1. maxVersions=N and we find at least N versions in the memstore. We can
safely avoid flushing any further versions to disk.
bq. 2. similarly minVersions=N and we find at least N versions in the
memstore. Now we can safely avoid flushing any further *expired* versions to
disk.
bq.
bq. This changes the Store flush to use the same mechanism that used for
compactions.
bq. I borrowed some code from the tests and refactored the test code to use a
new utility class that wraps a sorted collection and then behaves like
KeyValueScanner. The same class is used to create scanner over the memstore's
snapshot.
bq.
bq.
bq. This addresses bug HBASE-4241.
bq. https://issues.apache.org/jira/browse/HBASE-4241
bq.
bq.
bq. Diffs
bq. -----
bq.
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
1161347
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/CollectionBackedScanner.java
PRE-CREATION
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/KeyValueScanFixture.java
1161347
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestKeyValueHeap.java
1161347
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestKeyValueScanFixture.java
1161347
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestMinVersions.java
1161347
bq.
http://svn.apache.org/repos/asf/hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestStore.java
1161347
bq.
bq. Diff: https://reviews.apache.org/r/1650/diff
bq.
bq.
bq. Testing
bq. -------
bq.
bq. Ran all tests. TestHTablePool and TestDistributedLogSplitting error out
(with or without my change).
bq. I had to change three tests that incorrectly relied on old rows hanging
around after a flush (or were otherwise incorrect).
bq.
bq. No new test, as this should cause no functional change.
bq.
bq.
bq. Thanks,
bq.
bq. Lars
bq.
bq.
> Optimize flushing of the Store cache for max versions and (new) min versions
> ----------------------------------------------------------------------------
>
> Key: HBASE-4241
> URL: https://issues.apache.org/jira/browse/HBASE-4241
> Project: HBase
> Issue Type: Improvement
> Components: regionserver
> Affects Versions: 0.92.0
> Reporter: Lars Hofhansl
> Assignee: Lars Hofhansl
> Attachments: 4241-v2.txt, 4241.txt
>
>
> As discussed with with Jon, there is room for improvement in how the memstore
> is flushed to disk.
> Currently only expired KVs are pruned before flushing, but we can also prune
> versions if we find at least maxVersions versions in the memstore.
> The same holds for the new minversion feature: If we find at least minVersion
> versions in the store we can remove all further versions that are expired.
> Generally we should use the same mechanism here that is used for Compaction.
> I.e. StoreScanner. We only need to add a scanner to Memstore that can scan
> along the current snapshot.
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