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From Gaojinchao <gaojinc...@huawei.com>
Subject re: HConnectionManager max cached instances
Date Fri, 29 Apr 2011 02:57:23 GMT
In version 0.90.3, It has set for 2001

-----邮件原件-----
发件人: lohit [mailto:lohit.vijayarenu@gmail.com] 
发送时间: 2011年4月29日 10:52
收件人: dev@hbase.apache.org
主题: Re: HConnectionManager max cached instances

Thanks for the pointer. Even if we increase
hbase.zookeeper.property.maxClientCnxns
wouldn't the cache size still be 31?
I was wondering if there was way to avoid cache miss so that it would not
create new ZK connection.

2011/4/28 Ted Yu <yuzhihong@gmail.com>

> 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
> >
>



-- 
Have a Nice Day!
Lohit
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