Mozilla recently nightly/candidate build for 0.9.2.1 on NT4 (sp6). I found a 200KB/s memory leak whilst attempting to use the news client when Navigator was still attempting to connect to a site that was unresponsive. The site was hosted on IIS on NT4. Steps to reproduce: 1) Click on link to access webpage 2) Status bar says "Connecting to http://www.whatever.com/" and progress meter is in waiting mode, the server is unresponsive. 3) Switch to News client. 4) Attempt to start reading news (hosted on a different Unix server in my case) 5) Watch memory usage shoot upwards at rate of 200KB/s. Step 2) is likely to be the hardest to reproduce. The server was clearly having problems and at one point both Mozilla and Internet Explorer were giving "Connection refused" errors. I don't fully understand the internals but from an end user perspective it looked as though the problem was caused by the unresponsiveness of the NT server. If you press stop before step 3), then the leak does not occur. It only happens when navigator is left attempting to load the page in the background. I was able to shut down and restart Mozilla (by killing the huge process), reproducing this around eight times. Other sites did not cause the same problem.

How about setting up a unix machine with inetd configured to run "cat >/dev/null" or some other non-terminating process on a connection to port 80 (or any other port, if you make the port explicit in the URL)? This should at least provide a first-pass simulation of a hung server, although it may not have the exact same behavior as the hung server you were dealing with. If this doesn't reproduce the behavior, then (if Ian can still reproduce this at all) it would be a good idea to run some kind of packet sniffer or perhaps a logging proxy to log exactly what was getting sent to this server...

-> mailnews

Some additional info that may or may not be relevant, both the unresponsive NT server and the News server were in the same domain (though on different servers).

try again -> mailnews

does this still happen?

Unapersson, are you sure we didn't start leaking memory from the onset of the failure to connect to the http:// site? I must admit I've had difficulty (as you mention) connecting to a site that is down to get this reproduced...

It may be best to close this one, it was a long time since I reported it and I've not been able to recreate this since (due to having had no similar server problems since then). It may well have been resolved in the meantime. It was definately occuring when using Mail News though. I experimented with leaving the attempt to get an "http://" connection running until the failure to connect message appeared, but there was no leak. It was only when I simultaneously tried to read the mail server that this occurred. If I am able to recreate the situation at any point I'll reopen it.

okay, thanks. marking wfm.

verified for now (to get off radar). unapersson@hotmail.com, please re-open this if you see it again, thanks.