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Posted to user@zookeeper.apache.org by "mostolog@gmail.com" <mo...@gmail.com> on 2017/07/14 11:14:26 UTC

...likely client has closed socket...

Hi

Using zookeeper 3.5.3-beta we are getting a few log lines like:

    [2017-07-14 13:02:30,588] WARN Unable to read additional data from
    client sessionid 0xc00bee319ed0004, likely client has closed socket
    (org.apache.zookeeper.server.NIOServerCnxn)

Why zookeeper is "reading" adittional data from client if it already 
leave? Anyway, it the client is gone this shoudn't be considered an 
error, isnt it?

Otherwise shouldn't this message be DEBUG?

Can we safely ignore org.apache.zookeeper.server.NIOServerCnxn? (or this 
could hide severe issues in the future?)

Regards


Re: ...likely client has closed socket...

Posted by Camille Fournier <ca...@apache.org>.
If your clients call the close operation when they are done using ZK you
won't see this error. It is unexpected for your client to close the socket
without having called close. I suspect that this is an error in the way you
are using the ZK client.

On Mon, Jul 17, 2017 at 9:25 AM, mostolog@gmail.com <mo...@gmail.com>
wrote:

> Going to deploy a more recent version of clients, to see if the error is
> gone...
>
>
>
> On 14/07/17 16:07, Shawn Heisey wrote:
>
>> On 7/14/2017 5:14 AM, mostolog@gmail.com wrote:
>>
>>> Using zookeeper 3.5.3-beta we are getting a few log lines like:
>>>
>>>     [2017-07-14 13:02:30,588] WARN Unable to read additional data from
>>>     client sessionid 0xc00bee319ed0004, likely client has closed socket
>>>     (org.apache.zookeeper.server.NIOServerCnxn)
>>>
>>> Why zookeeper is "reading" adittional data from client if it already
>>> leave? Anyway, it the client is gone this shoudn't be considered an
>>> error, isnt it?
>>>
>> I'm no expert in ZK code, so I could be completely wrong in what I'm
>> going to say:
>>
>> This kind of message probably means that the normal TCP stack operation
>> (where a client will notify a server that it is closing the socket) was
>> somehow interrupted, possibly by a badly configured firewall or a
>> network problem.  There is always the possibility of a bug, but it is
>> more likely to be a problem somewhere else.  I do not believe that this
>> is a message that can be ignored -- it probably indicates the presence
>> of a real problem that must be fixed.
>>
>> If I'm wrong, hopefully someone who IS an expert will step up and
>> correct me.
>>
>> Thanks,
>> Shawn
>>
>>
>

Re: ...likely client has closed socket...

Posted by "mostolog@gmail.com" <mo...@gmail.com>.
Going to deploy a more recent version of clients, to see if the error is 
gone...


On 14/07/17 16:07, Shawn Heisey wrote:
> On 7/14/2017 5:14 AM, mostolog@gmail.com wrote:
>> Using zookeeper 3.5.3-beta we are getting a few log lines like:
>>
>>     [2017-07-14 13:02:30,588] WARN Unable to read additional data from
>>     client sessionid 0xc00bee319ed0004, likely client has closed socket
>>     (org.apache.zookeeper.server.NIOServerCnxn)
>>
>> Why zookeeper is "reading" adittional data from client if it already
>> leave? Anyway, it the client is gone this shoudn't be considered an
>> error, isnt it?
> I'm no expert in ZK code, so I could be completely wrong in what I'm
> going to say:
>
> This kind of message probably means that the normal TCP stack operation
> (where a client will notify a server that it is closing the socket) was
> somehow interrupted, possibly by a badly configured firewall or a
> network problem.  There is always the possibility of a bug, but it is
> more likely to be a problem somewhere else.  I do not believe that this
> is a message that can be ignored -- it probably indicates the presence
> of a real problem that must be fixed.
>
> If I'm wrong, hopefully someone who IS an expert will step up and
> correct me.
>
> Thanks,
> Shawn
>


Re: ...likely client has closed socket...

Posted by Shawn Heisey <ap...@elyograg.org>.
On 7/14/2017 5:14 AM, mostolog@gmail.com wrote:
> Using zookeeper 3.5.3-beta we are getting a few log lines like:
>
>    [2017-07-14 13:02:30,588] WARN Unable to read additional data from
>    client sessionid 0xc00bee319ed0004, likely client has closed socket
>    (org.apache.zookeeper.server.NIOServerCnxn)
>
> Why zookeeper is "reading" adittional data from client if it already
> leave? Anyway, it the client is gone this shoudn't be considered an
> error, isnt it? 

I'm no expert in ZK code, so I could be completely wrong in what I'm
going to say:

This kind of message probably means that the normal TCP stack operation
(where a client will notify a server that it is closing the socket) was
somehow interrupted, possibly by a badly configured firewall or a
network problem.  There is always the possibility of a bug, but it is
more likely to be a problem somewhere else.  I do not believe that this
is a message that can be ignored -- it probably indicates the presence
of a real problem that must be fixed.

If I'm wrong, hopefully someone who IS an expert will step up and
correct me.

Thanks,
Shawn