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From Ted Yu <yuzhih...@gmail.com>
Subject Re: HConnectionManager max cached instances
Date Fri, 29 Apr 2011 02:39:21 GMT
Increase value for the following parameter:
  <property>
    <name>hbase.zookeeper.property.maxClientCnxns</name>
    <value>30</value>

Please read my blog for long-term fix which should be commited soon:
http://zhihongyu.blogspot.com/2011/04/managing-connections-in-hbase-090-and.html

On Thu, Apr 28, 2011 at 7:26 PM, lohit <lohit.vijayarenu@gmail.com> wrote:

> Hi,
>
> By looking at HConnectionManager it looks like from a single node a max of
> 31 connections can be cached.
>
> >  static final int MAX_CACHED_HBASE_INSTANCES = 31;
>
> I read the comment that this is based on the assumption that max client
> connections to zookeeper is 30 from a single node.
> ZooKeeper has an option to change that value, but we seem to be doing lot
> of
> cache misses if we made more than 30 connections from a client.
> This cache miss end up making new ZK connection and if number of HTable
> operations are more, we see spike in ZooKeeper connections from single
> node.
>
> This is seen in hbase.0.90.2. Is there any work around for this apart from
> change the code?
>
> --
> Thanks
> Lohit
>

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