hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Doug Meil <doug.m...@explorysmedical.com>
Subject RE: heap memory allocation
Date Fri, 15 Apr 2011 14:39:01 GMT
The HBase book has come through some updates recently on these metrics.

http://hbase.apache.org/book.html#hbase_metrics


-----Original Message-----
From: saint.ack@gmail.com [mailto:saint.ack@gmail.com] On Behalf Of Stack
Sent: Friday, April 15, 2011 5:04 AM
To: user@hbase.apache.org
Cc: 陈加俊; hbase-user@hadoop.apache.org
Subject: Re: heap memory allocation

On Thu, Apr 14, 2011 at 9:50 PM, 陈加俊 <cjjvictory@gmail.com> wrote:
> How does heap memory allocated in regionserver ?
>
> Metrics:
>
> request=0.0, regions=1283, stores=2304, storefiles=1968, 
> storefileIndexSize=246, memstoreSize=791, compactionQueueSize=0, 
> usedHeap=5669, maxHeap=11991, blockCacheSize=2095157424, 
> blockCacheFree=419681872, blockCacheCount=24410, 
> blockCacheHitRatio=92, fsReadLatency=0, fsWriteLatency=0, 
> fsSyncLatency=0
>
>
>
> maxHeap=11991
> usedHeap=5669
>

This just the state of the JVM memory bean at the last update time.
Looks like you have given hbase 12G.  We're using about 5.5 Gig.   See
here for where we read it from the bean:
http://hbase.apache.org/xref/org/apache/hadoop/hbase/regionserver/HRegionServer.html#751
 These look like they report in MB.

> blockCacheSize=2095157424
> memstoreSize=791
> ????

These look like they report in bytes and MB.  Should make them all same units.  HBase has
a cache of hdfs blocks.  And memstore is where we write edits too before they get flushed
to the filesystem.

>
> Free=maxHeap-usedHeap?
>

Read the javadoc on the bean returned by
ManagementFactory.getMemoryMXBean() call.

St.Ack

>
> --
> Thanks & Best regards
> jiajun
>
Mime
View raw message