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From Brett Delle Grazie <brett.dellegra...@gmail.com>
Subject Re: Problem with tomcat and jk module
Date Tue, 24 Jul 2012 23:28:46 GMT
On 24 Jul 2012 19:59, "André Warnier" <aw@ice-sa.com> wrote:
>
> Piotr Wąchała wrote:
>>
>> ok, thanks for advice, but I checked my "front end" enviroment.
>> Before connection goes to front end apache, must go to firewall and next
to load balancer.
>> I remove from this chain load balancer, and it was still the same.
>> In firewall I dont observe teardown connecion or sth. like that. (I
can`t quit the firewall from this chain)
>> I try to attach pid and tid form tomcat to apache(adding %P %{tid}P %D
to apache LogFormat) and search the problem, but I think it isent good
clue. I cant exactly correkate problem in jklogfile and apache access.log
>
>
> I think that's normal.  The Apache access-log line only gets written when
the request is complete (and the response sent, at least partially). But
since here the client connection is broken, there is no way to send
anything to the client, and probably the access log line does not even get
written then.
> You may have more success with the error log, setting the LogLevel to
"info" or so.
>
>
>> The funny thing is the whole system works ok. for over 2y and in last
week just from day to another day it starts to work terrible.
>

Check that your network equipment (firewalls / switches etc.) isn't
flapping due to mixed/wrong auto negotiation settings. It can cause odd
problems like this.

>
> That would then tend to indicate that the problem is due to some (new)
element outside of (apache+mod_jk+tomcat), no ?
> If you cannot remove the firewall, can you look at the firewall logs ?
>
> Alternatively, can you install some program like wget or curl, to
simulate a client somewhere and tell you when the client connection is
dropped ?
> (This being an alternative to doing a real network trace at the client
level)
>
> Also maybe check this archived thread, there are some suggestions to try
out : http://www.mail-archive.com/users@tomcat.apache.org/msg55780.html
> (sound similar ? download the perl script that is mentioned and try it
out as a client)
>
>
>> I even change my isp, still no progress.
>
> But the firewall remained the same ?
>
>
>>
>> Q: What is causing that connection to close, before the response can be
sent ?
>> A: I will try to answer to this after 9pm.
>>
>> Piotr
>>
>> W dniu 2012-07-24 15:12, André Warnier pisze:
>>>
>>> Hi.
>>>
>>> Thanks for the very complete information about your environment.
>>>
>>> Piotr Wąchała wrote:
>>>>
>>>> Hi,
>>>> Maybe someone can help me with my tomcat problem.
>>>> Hope that wont be a big problem for you.
>>>>
>>>> Im observing that our client are disconnected from server, that is
very bad situation.
>>>>
>>> In my experience, this kind of message :
>>>
>>>> In jklogfile.log
>>>> [Tue Jul 24 08:43:22 2012] [17466:47245693265248] [info]
jk_handler::mod_jk.c (2620): Aborting connection for worker=loadbalancer
>>>> [Tue Jul 24 08:43:22 2012] [17023:47245693265248] [info]
ajp_process_callback::jk_ajp_common.c (1885): Writing to client aborted or
client network problems
>>>> [Tue Jul 24 08:43:22 2012] [17023:47245693265248] [info]
ajp_service::jk_ajp_common.c (2543): (worker1) sending request to tomcat
failed (unrecoverable), because of client write error (attempt=1)
>>>
>>>
>>> in 99% of the cases, indicates a problem that is NOT with Apache httpd
or mod_jk or Tomcat.
>>> It is that by the time (tomcat+mod_jk+apache) want to send a response
back to the client (the user's browser), the eonnection to that user's
browser does not exist anymore, so they cannot send it. (And all the other
messages after that, are because after this error, things kind of get out
of sync.)
>>>
>>> This can happen
>>> - either because the user in front of that browser decides that he has
waited long enough, and clicks on another link (or closes the browser)
>>> - or because some piece of equipment or software closes that connection
before (tomcat+mod_jk+apache) had a chance to send back the response
>>>
>>> (It happens that in-between routers/firewalls/gatewaysw/proxies, if
they do not see anything happen on a client connection for a while, will
close that connection - to gain on the number of connections that they must
manage).
>>>
>>> (Both either/or causes above are also more likely if your Tomcat
requests are so that they take a long time to be processed and generate a
response)
>>>
>>> So the first place to look, is the link between your client (presumably
a user browser) and the front-end Apache.  What is causing that connection
to close, before the response can be sent ?
>>>
>>>
>>>
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>>>
>>>
>>
>>
>>
>
>
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