Thanks Mark, see inline comments. >> [mailman@myhost] ~/logs |> grep testlist subscribe | grep acase >> Sep 28 17:15:14 2011 (4401) testlist: new ac...@example.com, admin mass >> sub >> Sep 28 17:19:36 2011 (5821) testlist: deleted ac...@example.com; member >> mgt page >> [mailman@myhost] ~/logs |> ../bin/list_members testlist | grep acase >> ac...@example.com >> [mailman@myhost] ~/logs |> > > > There is a bug in the Mailman 2.1 branch, but the above is not it. The > above log shows that ac...@example.com was added by admin mass subscribe > at 17:15:14 and then a bit more than 4 minutes later, was removed by > checking the unsub box on the admin Membership List and submitting.
I was trying to show that even after the user was removed, they're still listed as a member. > If you check your web server logs, you will find POST transactions to > the admin page for both these events. Agreed. >> The same also happens when subscribing. I will mass subscribe users (or >> when users confirm subscription via email/web), the logs indicated that >> they have been subscribed successfully, but then when I go look them up, >> they are not listed on the members list. >> >> This happens sporadically, but I am generally able to reproduce the >> error >> if I do it a couple times in a row. > > > This is possibly a manifestation of the bug, but I'm surprised it is > happening that frequently. Easiest way for me to replicated the problem is: 1) check the unsubscribe box for user A then hit submit 2) after reload check the unsubscribe box for user B then hit submit 3) reaload the "membership list" page and user B is back on the list This happens even after I wait a couple seconds in between each step. >> I'm suspicious there may be a locking issue and config.pck is reverting >> to >> config.pck.last. I found this thread rather helpful in analyzing >> potential problems, but I have yet to figure anything out: >> http://web.archiveorange.com/archive/v/IezAOgEQf7xEYCSEJTbD > > > The thread you point to above is relevant, but it is not a locking > issue. The problem is due to list caching in Mailman/Queue/Runner.py > and/or nearly concurrent processes which first load the list unlocked > and later lock it. The issue is that the resolution of the config.pck > timestamp is 1 second, and if a process has a list object and that list > object is updated by another process within the same second as the > timestamp on the first process's object, the first process won't load > the updated list when it locks it. This can result in things like a > subscribe being done and logged and then silently reversed. The result sounds the same, but would this happen even if I'm loading the page with more than a second in between each step outlined above? > List locking is working as it should. The issue is that the first > process doesn't reload the updated list when it acquires the lock > because it thinks it already has the latest version. > > I thought I had fixed this on the 2.1 branch, but it seems I only fixed > it for the now defunct 2.2 branch. > > A relevant thread starts at > <http://mail.python.org/pipermail/mailman-users/2008-August/062862.html> > and continues at > <http://mail.python.org/pipermail/mailman-developers/2008-August/020329.html> > > The patch in the attached cache.patch file should fix it. I applied the patch but it doesn't seem to have made a difference. >> In addition if I just run the following commands over and over, then the >> bug never seems to come up. This is part of why I am worrying about >> locking: >> bin/add_members ... >> bin/remove_members ... > > > That won't do it. bin/add_members alone will do it, but only if there is > a nearly concurrent process updating the same list. > > >> Is there a good way to test locking between servers? I've run the >> tests/test_lockfile.py, but it reports it is OK. >> >> Any and all help would be GREATLY appreciated. We've been trying to >> triage this bug for weeks and it is terribly disruptive for our users. > > > The post at > <http://mail.python.org/pipermail/mailman-users/2008-August/062862.html> > contains a "stress test" that will probably reproduce the problem. Correct. Only one subscriber was subscribed to each test list. Keep in mind that in the stress test given if you use a sleep counter of 5 with 6 lists, that means you're waiting _30 seconds_ before the next add_member command is run for that list (I'm assume the timing issue is per-list, not per run of add_members). Even if you set the timer down to 1 that's a 6 second sleep. This shouldn't effect a cache that we're comparing for the given second. Anyway, my script ran fine with the 5 second sleep (30 seconds per list add), but showed discrepancies with a 3 second sleep. > I suspect your Mailman server must be very busy for you to see this bug > that frequently. However, it looks like I need to install the fix for > Mailman 2.1.15. We run about 600 different mailing lists for our department and this has been a continues headache. I appreciate all the hard work you guys do. > It is also curious that the only reports of this that I can recall both > come from solaris users. There may be complications in your case due to > NFS, but locking shouldn't be the issue. Run the stress test and see if > it fails. If it does, try the patch. Patch didn't seem to help. Is there an easy way to omit the caching in this? Thanks, -- Drew > > Let us know what happens. > > -- > Mark Sapiro <m...@msapiro.net> The highway is for gamblers, > San Francisco Bay Area, California better use your sense - B. Dylan > > _______________________________________________ Mailman-Developers mailing list Mailman-Developers@python.org http://mail.python.org/mailman/listinfo/mailman-developers Mailman FAQ: http://wiki.list.org/x/AgA3 Searchable Archives: http://www.mail-archive.com/mailman-developers%40python.org/ Unsubscribe: http://mail.python.org/mailman/options/mailman-developers/archive%40jab.org Security Policy: http://wiki.list.org/x/QIA9
