ajp13 and HTTPClient from innovation.ch

[Brian Vetter <bj...@motive.com>]

I was trying to get ajp13 and tomcat 3.2b4 working with our client.  The client is using the HTTPClient library from innovation.ch ( http://www.innovation.ch/java/HTTPClient/ ).  When using mod_jk and ajp12, things seem to be working ok.  We get really strange behaviour when the server is configured to use ajp13.  After a handful of requests are sent to the apache/tomcat server from the client, the responses stop coming back.  Instead, they get stuck in the server.

>From watching the log files, it would appear that everything is completing just fine in tomcat and modjk/apache.  However, no response data is ever sent back. I then crank up IE or Netscape and start hitting the server and servlets. I get really bizarre behaviour.  The first two attempts get back server errors (500).  The third attempt gets back the results from one of the requests sent by my other client (one whose results are stuck in mod_jk or somewhere).  I can iterate this many times over with IE/Netscape until I exhaust all of the "stuck" requests.  Once that happens, I get the request data that the browser had asked for.

Has anyone had any similar kinds of problems with ajp13 and mod_jk?  One of the features of the HTTPClient is pipelining.  I thought this might cause some problems so I turned it off using some System properties but still got the same results.

I've also witnessed another strange problem using the httpclient i/f and ajp13. We have an apache module that makes a couple of subrequest to tomcat.  Sometimes, but not always, an error is returned to the client.  We see an error message in the ajp log that says "read_into_msg_buff: Error - read_fully_from_server failed".  In the tomcat log file I see a write error on a socket while it is trying to send the response.  Strangely enough, I don't see this happening when using IE to hit the same servlet.  

I'm not sure which is at fault - HTTPClient or mod_jk/ajp13.

Brian
bjv@motive.com