[
https://issues.apache.org/jira/browse/HADOOP-2636?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12563645#action_12563645
]
stack commented on HADOOP-2636:
-------------------------------
In HLogKey, was it just a case of a misnamed data member? All along it was a
store but we were calling it region? See below:
{code}
- Text regionName = new Text();
+ Text storeName = new Text();
{code}
Can this string creation be avoided in HStore; e.g. can storeName be Text?
{code}
+ || (key.getStoreName().toString().compareTo(storeName) != 0)
{code}
Logging below at INFO level seems inappropriate:
{code}
+ LOG.info("Not flushing cache for " + storeName +
+ " because it has 0 entries");
{code}
This kind of logging doesn't help (though I think this log is just a line moved
from elsewhere):
{code}
+ LOG.debug("nothing to compact for " + this.storeName);
{code}
Should say why there is nothing to compact -- e.g. only one file present or
holds references.
Just remove rather than comment out?
{code}
- HStoreKey rowKey = new HStoreKey(row, timestamp);
+/* HStoreKey rowKey = new HStoreKey(row, timestamp); */
{code}
HStoreSize inner class is no longer needed because the check is local to HStore
where before it was higher up in HRegion? The info HStoreSize carried is now
all availble in the context where the check is being done?
Nice how you cleaned up lease-making/updating.
Why make RowMap non-private? Its used by inner classes?
The below no longer makes use of TextSequences? Any reason for that? (TS was
means of cutting down on object creations. Profiling, using TSs made a big
difference).
{code}
- Text qualifier = HStoreKey.extractQualifier(col);
+ Text member = HStoreKey.extractMember(col);
{code}
> [hbase] Make cache flush triggering less simplistic
> ---------------------------------------------------
>
> Key: HADOOP-2636
> URL: https://issues.apache.org/jira/browse/HADOOP-2636
> Project: Hadoop Core
> Issue Type: Improvement
> Components: contrib/hbase
> Affects Versions: 0.16.0
> Reporter: stack
> Assignee: Jim Kellerman
> Fix For: 0.17.0
>
> Attachments: patch.txt, patch.txt, patch.txt
>
>
> When flusher runs -- its triggered when the sum of all Stores in a Region > a
> configurable max size -- we flush all Stores though a Store memcache might
> have but a few bytes.
> I would think Stores should only dump their memcache disk if they have some
> substance.
> The problem becomes more acute, the more families you have in a Region.
> Possible behaviors would be to dump the biggest Store only, or only those
> Stores > 50% of max memcache size. Behavior would vary dependent on the
> prompt that provoked the flush. Would also log why the flush is running:
> optional or > max size.
> This issue comes out of HADOOP-2621.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
