-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Migual Angel,
On 11/10/16 5:51 AM, Roldan, Miguel Angel [Global Data & Content] wrote: > Thanks for your help. After a lot of tests we finally realized it > was related with having tomcat configured to recycle requests and > using apache velocity. I use Apache Velocity and have no such concurrency issues. Note that "recycling requests" doesn't mean what you might think it does: in Tomcat, "recycling request facades" means that the facades are discarded . > We modify the configuration RECYCLE_FACADES setting it to true and > the problem disappear. Then the problem is with your application retaining references to request and/or response objects after the request should have completed. 99% of the time this is the reason for reports of the kind you gave. This is not a bug in Tomcat, nor is it a bug in Velocity. It's a bug in your application. - -chris > -----Original Message----- From: Christopher Schultz > [mailto:ch...@christopherschultz.net] Sent: viernes, 04 de > noviembre de 2016 23:26 To: Tomcat Users List > <users@tomcat.apache.org> Subject: Re: Apache tomcat concurrency > issue > > Miguel Angel, > > On 11/3/16 12:52 PM, Roldan, Miguel Angel [Global Data & Content] > wrote: > > (Moving this up to the top:) > >> Httpd apache server on the front-end v. 2.2 connected to apache >> tomcat using AJP connector 1.3 > >> Apache tomcat 7.0.56 > > Thanks. > >> We are facing some random concurrency issues in our tomcat >> environments. > > >> 1. We have a web application deployed on Tomcat that handles >> requests from browsers (AJAX and non-AJAX) and also from an >> applet. > >> 2. The requests send by the browser and always gets and >> posts (with application/x-www-form-urlencoded format) > >> 3. The requests made by the applet are compressed and send >> in binary, they are handled by a different Servlet that reads >> the content by executing request.getInputStream(). > > Are you compressing and sending a big blob called "data" or > something similar? Or are you sending multiple parameters > separately compressed? > >> 4. Randomly, mainly after opening the applet from the >> current session or in another session executed on the same server >> (which send some requests in parallel) requests send from the >> browser arrives to the server with an empty >> request.getParameterMap() > > If you are calling request.getInputStream, then you will never get > anything in the parameter map. If your code consumes the request > body in a POST, then Tomcat cannot parse it again. > >> 5. We have reviewed that the request was well formed when it >> leaves the browser and also we are able to monitor it with TCP >> Dump and see that arrives correctly to tomcat. > > Good. > >> 6. We have introduced a filter on the first position of the >> filter chain: org.apache.catalina.filters.RequestDumperFilter >> and we have validated that at this point we have already lost all >> of the parameters > > Good thinking. Are you SURE it's the first filter in the chain? We > aware that the RequestDumperValve will rob the data from your > applicatio n. > >> 7. If we try to execute the request.getInputStream() for >> this problematic requests what we see is that the byte array >> that returns belongs to another request made before to the >> server. > > Obviously, that shouldn't happen. > >> 8. If we re-submit the same request after, it works fine. >> They don't have any kind of special character or exceed a >> certain length. > >> 9. Environment configuration: > > >> O.S. - Oracle linux > > > >> 10. Sometimes we are able to reproduce the issue on a >> eclipse-tomcat environment using http connector and we have >> validated that the flag used by the class >> org.apache.catalina.connector.Request parametersParsed is set to >> true. > > > >> Do you have any kind of suggestions on how to further >> investigate the issue? > > Are you able to re-test with an updated version of Tomcat 7? > Current version is 7.0.72. Your version is ~2 years old. > > Can you post your <Connector> configuration? > > Thoughts about what might be happening: > > 1. Application concurrency/request-object retention bug 2. > maxPostSize value too low -- Tomcat is rejecting the request in a > way unexpected by the application 3. Edge case/bug in Tomcat that > has been fixed in a more-recent version? > > -chris > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > > ________________________________ > > "This e-mail, any associated files and the information contained > in them are confidential and is intended for the addressee(s) only. > If you have received this message in error please notify the > originator and delete the email immediately. The unauthorised use, > disclosure, copying or alteration of this message is strictly > forbidden. E-mails to and from the company are monitored for > operational reasons and in accordance with lawful business > practices. Any opinions expressed are those of the individual and > do not necessarily represent the views of the company. 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