hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon" <t...@cloudera.com>
Subject Re: Review Request: HBASE-2468: Improvements to prewarm META cache on clients.
Date Thu, 10 Jun 2010 15:55:05 GMT


> On 2010-06-10 08:53:41, Jonathan Gray wrote:
> > src/main/java/org/apache/hadoop/hbase/client/MetaScanner.java, line 109
> > <http://review.hbase.org/r/98/diff/5/?file=944#file944line109>
> >
> >     Hmm, wouldn't that be Math.min then?  If rowLimit = 5 and scanner.caching =
100, we want to only do 5?

woops, yes :)


- Todd


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.hbase.org/r/98/#review176
-----------------------------------------------------------


On 2010-06-09 15:50:59, Mingjie Lai wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.hbase.org/r/98/
> -----------------------------------------------------------
> 
> (Updated 2010-06-09 15:50:59)
> 
> 
> Review request for hbase, Todd Lipcon and stack.
> 
> 
> Summary
> -------
> 
> HBASE-2468: Improvements to prewarm META cache on clients.
> 
> Changes:
> 1. Add new HTable methods which support region info de/serialation, and region cache
prewarm: 
> - void serializeRegionInfo(): clients could perform a large scan for all the meta for
the table, serialize the meta to a file. MR job can ship a copy of the meta for the table
in the DistributedCache
> - Map<HRegionInfo, HServerAddress> deserializeRegionInfo(): MR job can deserialize
the region info from the DistributedCache 
> - prewarmRegionCache(Map<HRegionInfo, HServerAddress> regionMap): MR job can prewarm
local region cache by the deserialized region info.
> 
> 2. For each client, each region cache read-miss could trigger read-ahead some number
of rows in META. This option could be turned on and off for one particular table. 
> 
> 
> This addresses bug HBASE-2468.
>     http://issues.apache.org/jira/browse/HBASE-2468
> 
> 
> Diffs
> -----
> 
>   src/main/java/org/apache/hadoop/hbase/client/HConnection.java 853164d 
>   src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java ed18092 
>   src/main/java/org/apache/hadoop/hbase/client/HTable.java 7ec95cb 
>   src/main/java/org/apache/hadoop/hbase/client/MetaScanner.java d3a0c07 
>   src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java 95e494a 
> 
> Diff: http://review.hbase.org/r/98/diff
> 
> 
> Testing
> -------
> 
> Unit tests passed locally for me. 
> 
> 
> Thanks,
> 
> Mingjie
> 
>


Mime
View raw message