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https://issues.apache.org/jira/browse/HADOOP-2443?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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stack updated HADOOP-2443:
--------------------------
Resolution: Fixed
Status: Resolved (was: Patch Available)
Committed. Had some minor questions -- see below -- but it ain't enough to
hold up patch and I'm afraid patch would rot if left hang (It touches lots of
classes). Resolving. Thanks for the patch Bryan.
Here's the couple of items:
Here in HConnectionManager:
{code}
+ scannerId = server.openScanner(
+ metaLocation.getRegionInfo().getRegionName(),
+ COLUMN_FAMILY_ARRAY, EMPTY_START_ROW, LATEST_TIMESTAMP,
+ null);
{code}
... EMPTY_START_ROW will work but 'startRow' would be easier to read (It'd work
too -- right?).
Here:
{code}
+ } while (startRow.compareTo(EMPTY_START_ROW) != 0);
{code}
.. EMPTY_ROW or a new define, LAST_ROW, would have been more readable, don't
you think?
This 999... 'trick' should be done as a method -- in HTableInfo? -- since you
do it twice:
{code}
+ Text tableKey = new Text(tableName.toString() + ",,99999999999999");
{code}
> [hbase] Keep lazy cache of regions in client rather than an 'authoritative'
> list
> --------------------------------------------------------------------------------
>
> Key: HADOOP-2443
> URL: https://issues.apache.org/jira/browse/HADOOP-2443
> Project: Hadoop
> Issue Type: Improvement
> Components: contrib/hbase
> Reporter: stack
> Assignee: Bryan Duxbury
> Fix For: 0.16.0
>
> Attachments: 2443-v10.patch, 2443-v3.patch, 2443-v4.patch,
> 2443-v5.patch, 2443-v6.patch, 2443-v7.patch, 2443-v8.patch, 2443-v9.patch
>
>
> Currently, when the client gets a NotServingRegionException -- usually
> because its in middle of being split or there has been a regionserver crash
> and region is being moved elsewhere -- the client does a complete refresh of
> its cache of region locations for a table.
> Chatting with Jim about a Paul Saab upload issue from Saturday night, when
> tables are big comprised of regions that are splitting fast (because of bulk
> upload), its unlikely a client will ever be able to obtain a stable list of
> all region locations. Given that any update or scan requires that the list
> of all regions be in place before it proceeds, this can get in the way of the
> client succeeding when the cluster is under load.
> Chatting, we figure that it better the client holds a lazy region cache: on
> NSRE, figure out where that region has gone only and update the client-side
> cache for that entry only rather than throw out all we know of a table every
> time.
> Hopefully this will fix the issue PS was experiencing where during intense
> upload, he was unable to get/scan/hql the same table.
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