-----Original Message-----
From: André Warnier [mailto:a...@ice-sa.com]
Sent: 08 January 2014 02:52
To: Tomcat Users List
Subject: Re: Packet misses in Tomcat


Christopher Schultz wrote:
> Hash: SHA256
> André,
> On 1/7/14, 5:09 AM, André Warnier wrote:
>> I do not pretend to know your system, nor your application, nor that
>> the following is a definite explanation.  But on the base of the
>> currently available data, I would say : - it is quite unlikely that
>> Tomcat 7 is randomly "dropping requests". If it was, then I would
>> imagine that this list would be overflowing with cries for help.
>> There is quite a bit of traffic on this list related to Tomcat 7, but
>> I don't recall seeing any significant number of issues mentioning
>> "dropped requests". - it also doesn't seem, from your
>> wireshark-related observations, that the requests are being lost
>> outside of Tomcat. - so I would say at this point, that the most
>> likely place for requests to disappear is in your own application.
> It seems that Tomcat is not logging the request in its access log, so
> it's more likely that the request is either malformed to such an
> extent that Tomcat rejects the request altogether or that the request
> never reaches Tomcat.
Hi. Of course I am going essentially by what the OP provided earlier as 
information, and he has not provided much details on the "disappearing" 
requests themselves, or on the channel through which these requests were 
reaching Tomcat.
But one thing that he did mention, is that these requests are similar - and 
even in general the same - as other requests which do get processed normally.
As per his own words :

"For the query regarding "All requests", all requests do not disappear. More 
importantly, sometimes all requests  reach the application when I POST same set 
of requests. To give a rough picture, 1-2 requests fail in a set of 45-50 
requests and this behaviour varies [The request which failed in my one test 
cycle succeeds in another cycle]."

If we take this at face value, then it should not be so that these requests are 
so malformed that Tomcat discards them without further ado.
Also - but maybe I'm wrong there - I would expect, if Tomcat discards a request 
for being malformed - that something would appear in the Tomcat error log.  But 
according to the OP it doesn't.
Finally - and there is a bit of an assumption on my part here - I assume that 
when the OP says that he sees the request with Wireshark (prior to it 
"disappearing" in Tomcat), he was running Wireshark on the Tomcat host itself.  
That would make it unlikely that another external component is at play.

All of the above led me to suspect that something in the application itself may 
be playing a role here.

Of course, that all does not necessarily prove that some other component than 
Tomcat is not dropping some packets/requests.

Clarifications for the missed information:
- Wireshark runs on the same machine where Tomcat runs
- Channel through which these requests were reaching Tomcat
- HTTP Chanel
- Can you describe your deployment? Are you accessing Tomcat directly via HTTP? 
What networking components are between your test client(s) and Tomcat
- A war file with a servlet to POST the requests.
- There are 2 machines (LAN) where client and servers are installed. Client is 
used to send the requests to Server.
- Disabled the firewall in the server machine
- Tomcat will be accessed directly via HTTP
- This issue occurs even if I use loopback address/localhost instead of Server 
IP Address in the request URL (Install both client and server in the same 
- Tested with both "apache-tomcat-7.0.27.exe" and " 
- Also, Windows event logs will not have any entries when the requests getting 

Strange that this is happening only to me.

Overnight run of my application with Jetty Server(1167 requests) did not miss 
any requests. So I am hoping that application is not contributing to the 
missing requests. I may be wrong here.

Is there any way to get more logs on request processing in Tomcat?


DISCLAIMER: This electronic message and any attachments to this electronic 
message is intended for the exclusive use of the addressee(s) named herein and 
may contain legally privileged and confidential information. It is the property 
of Celstream Systems Private Limited. If you are not the intended recipient, 
you are hereby strictly notified not to copy, forward, distribute or use this 
message or any attachments thereto. If you have received this message in error, 
please delete it and all copies thereof, from your system and notify the sender 
at Celstream Systems or administrat...@celstream.com immediately.

To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org

Reply via email to