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https://issues.apache.org/jira/browse/HBASE-3588?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13001654#comment-13001654
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Ted Yu commented on HBASE-3588:
-------------------------------
The new method:
{code}
public MemStore(final Configuration conf,
final KeyValue.KVComparator c,
final ReadWriteConsistencyControl rwcc) {
{code}
would produce this test failure:
{code}
testMultipleVersionsSimple(org.apache.hadoop.hbase.regionserver.TestMemStore)
Time elapsed: 0.007 sec <<< ERROR!
java.lang.NoSuchMethodError:
org.apache.hadoop.hbase.regionserver.MemStore.<init>(Lorg/apache/hadoop/conf/Configuration;Lorg/apache/hadoop/hbase/KeyValue$KVComparator;)V
at
org.apache.hadoop.hbase.regionserver.TestMemStore.testMultipleVersionsSimple(TestMemStore.java:477)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
{code}
> Proposal to optimize ReadWriteConsistencyControl
> ------------------------------------------------
>
> Key: HBASE-3588
> URL: https://issues.apache.org/jira/browse/HBASE-3588
> Project: HBase
> Issue Type: Improvement
> Components: regionserver
> Reporter: dhruba borthakur
> Assignee: dhruba borthakur
> Attachments: rwcc.trunk.1, rwcc.trunk.1
>
>
> The ReadWriteConsistencyControl (RWCC) mechanism facilitates making a set of
> memstore updates atomically visible to readers. Also, the
> rwcc.completeMemstoreInsert() blocks till the memstore read point advances to
> the current writeNumber. This is done to ensure that if an application that
> does a put immediately issues a new get call for the same key, then the get
> should see the values inserted by the previous call to put. The current
> implementation assumes this worst-case and penalizes the put rpc to not
> return to the client until the read point advances to this transaction's
> write number.
> In many use-cases, the application never actually issues a get for the most
> recent put that it inserted. In this case, it would be nice if we can
> transfer the penalty (of blocking) to the get call that follows the initial
> put.
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