>________________________________________ >From: Mark Thomas [ma...@apache.org] >Sent: Thursday, December 26, 2013 3:19 PM >To: Tomcat Users List >Subject: Re: Request Timeout and empty post data issue > >On 26/12/2013 20:45, Peter Rifel wrote: >> Hello, >> >> I'm currently running Tomcat 7.0.42 on Ubuntu 12.04 with OpenJDK >> 1.7.0_25. I'm using Apache Tomcat Native library 1.1.27 with APR >> version 1.4.6. >> >> I'm noticing in my access logs that some of our POST requests don't >> have any POST data and all have response times of a few ms over >> 20000ms. I'm trying to figure out whether this issue is client side >> or server side. The response code and response size for these >> requests are normal. Can anyone tell me under what circumstances >> this would happen? > >It depends. > >The connectionTimeout is also the socket timeout. If at any time Tomcat >is (trying to) read data from the client or write data to the client and >no data is available (reading) or read (writing) for the timeout period >then the read / write will fail. > >It sounds like the client sends the request and then either doesn't send >the whole body, only sends part of the body or pauses for longer than >connectionTimeout while sending the body. The request body is therefore >missing / incomplete so can't be processed. Whether that results in an >error response will depend on your application. > >> I noticed that our connector's connectionTimeout >> is set to 20000ms, but it wouldn't make sense for that value to be a >> part of this issue because a connection timeout only occurs when the >> URI hasn't been received by tomcat in that amount of time, which is >> clearly not happening here (I was able to confirm this with telnet; a >> connection timeout will not write anything to the access logs). > >The above statement is incorrect. See the explanation preceding it.
This is what the documentation on the Configuration Reference page says, so if it is incorrect it should be updated. > >> The "request" is making it to my servlet (logging confirms this) but >> for some reason tomcat doesn't see any request parameters and all of >> the response times in our access logs are just above 20 seconds. >> Does this mean that my servlet is taking 20 seconds to process the >> request? > >Unlikely. It almost certainly means Tomcat is waiting 20s for the >request body to turn up. > > >> Is there some other timeout value somewhere that defaults >> to 20 seconds? > >No. > >> Is there a way for me to see exactly what is taking >> so long? > >Wireshark. > >> Its incredibly hard to debug this because we cant reproduce >> this bug on our own without any post data and <1% of our production >> traffic is having this issue. To try and gather more info on this, I >> added a servlet filter that logs all of our POST request parameters >> to the access log and I can confirm that there are no parameters on >> these specific requests. > >That makes it look very much like a client issue. I'd log the size of >the request body as well. A request body size of > 0 and no POST data >would point to a client issue. > >> The lack of post data makes me think its a client issue, but that >> doesn't explain why all of these requests take ~20 seconds to be >> processed. > >See above. > >Mark > I’m logging the Content-length header and it has expected values, mostly between 300 and 800 bytes. The requests are coming from a custom flash player that is being in embedded in users’ browsers that are out of our control, so it does make it difficult to debug with only 1% of our traffic seeing this problem. I will run wireshark on tomcat to try and get a better idea of where the issue is, thank you for the suggestion. Peter --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
