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Date: Thu, 22 Apr 2010 09:00:46 +0200
From: Julien Vey <Julien.Vey@bull.net>
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To: zookeeper-user@hadoop.apache.org
Subject: Re: Client reconnection after a connection loss
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Thanks for your help Patrick.

I'm already having a look at it.

Julien
> Hi Julien,
>
> take a look at the FAQ for some background:
> http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A3
>
> Basically when your client connects to the server it provides a 
> "timeout" value. If the server doesn't hear from your client within 
> this timeout period (we do heartbeating for you in a background 
> thread, you don't have to worry about this) then it will expire the 
> session.
> http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgrammers.html#ch_zkSessions 
>
>
> You have a watcher for the session - it will be notified both on 
> disconnect but also when/if the session is expired. An expired session 
> is invalid, if this happens you have to create a new session. This is 
> different from a disconnect notification, where you just wait for the 
> client library to reconnect you to the cluster (say you lose 
> connectivity to the server)
>
> Patrick
>
> On 04/21/2010 01:44 AM, Julien Vey wrote:
>> Hi all,
>>
>> I'm currently working with ZooKeeper in CXF D-OSGI and i'm facing a
>> problem that would require your help.
>>
>> When a client is connected to the ZooKeeper server, and the connection
>> is lost, it throws a ConnectionLossException.
>> The problem is when the connection is back, the client doesn't reconnect
>> itself. I can see the following trace on the server
>>
>> 2010-04-20 17:44:21,526 - INFO [NIOServerCxn.Factory:>
>> 0.0.0.0/0.0.0.0:2181:NIOServerCnxn$Factory@251] - Accepted socket
>> connection from /129.183.128.230:60471
>> 2010-04-20 17:44:21,526 - INFO [NIOServerCxn.Factory:
>> 0.0.0.0/0.0.0.0:2181:NIOServerCnxn@742] - Client attempting to renew
>> session0x1281ba54e900005 at /129.183.128.230:60471
>> 2010-04-20 17:44:21,527 - INFO [NIOServerCxn.Factory:
>> 0.0.0.0/0.0.0.0:2181:NIOServerCnxn@1424] - Invalid session
>> 0x1281ba54e900005 for client /129.183.128.230:60471, probably expired
>> 2010-04-20 17:44:21,527 - INFO [NIOServerCxn.Factory:
>> 0.0.0.0/0.0.0.0:2181:NIOServerCnxn@1286] - Closed socket connection for
>> client /129.183.128.230:60471 which had sessionid 0x1281ba54e900005
>>
>> The client tries to reconnect with an expired session id.
>> Is it possible to configure zookeeper in order that it accepts this
>> connection by recreating a new session, or maybe something else that
>> would make the reconnection works ?
>>
>> Thanks in advance for your help
>>
>> Julien.
>>
>>
>>
>
>