Hey Zed, First off, congrats on 1.0 and thanks for all your hard work.
On your list of items, I clearly left out some info that I should have included: 1. I'm using PostgreSQL and the C bindings. 2. I'm using the ActiveRecord store. 3. DNS... Okay, I'll take a look at this. I think we're okay here but I will double check. 4. Not using memcached. 5. Interesting. I'll check this one too. I'll check out your list of debugging suggestions. I may just skip to #4 as that's worked for me in the past. Cheers, Hunter On Jan 24, 2007, at 1:07 AM, Zed A. Shaw wrote: > On Tue, 23 Jan 2007 21:53:39 -0800 > Hunter Hillegas <[EMAIL PROTECTED]> wrote: > >> Howdy, >> >> I'm trying to debug a situation where a Rails app running on Mongrel >> +Apache stops listening to requests. Restarting Mongrel and Apache >> brings it back to life. >> >> First off, here's some info on versions, etc...: > > Here's the shortlist of stuff so far that can cause this: > > 1) Using the stock mysql.rb that comes with rails rather than using > the compiled mysql gem. > 2) Use a pstore for sessions, or actually trying to negotiate file > locking in general. > 3) Trying to resolve dns queries against a slow DNS server or > broken one. > 4) Using memcached and putting keys in it with a space or \0 char > in them (memcached don't like that and will block the world). > 5) An interesting new one is having Monit check the mongrel port on > sites with long running requests. What happens is since rails > blocks further requests during these requests, and monit is > typically told to restart when they're slow, you'll get frequent > "slow" requests so monit will frequently restart mongrels for no > apparent reason. > > Ways to debug this include: > > 1) Using lsof -i -P to see what's open. > 2) Attaching to the stuck process with gdb and using some of the > Ruby gdb scripts out there to force an exception to be thrown. > Then look in the mongrel.log to see what is logged. > 3) Running strace or truss on the stuck process to see what system > call it's doing. If it's repeatedly running select() then that > means it is most likely trying to write to a socket but getting > nothing back. This happens in the memcached case especially. > 4) Praying to some ancient god for redemption. > > I hear #4 works really well if you're bathed in the blood of 7 > orphaned virgins, but I'm not that hardcore. > > -- > Zed A. Shaw, MUDCRAP-CE Master Black Belt Sifu > http://www.zedshaw.com/ > http://www.awprofessional.com/title/0321483502 -- The Mongrel Book > http://mongrel.rubyforge.org/ > http://www.lingr.com/room/3yXhqKbfPy8 -- Come get help. > _______________________________________________ > Mongrel-users mailing list > Mongrel-users@rubyforge.org > http://rubyforge.org/mailman/listinfo/mongrel-users _______________________________________________ Mongrel-users mailing list Mongrel-users@rubyforge.org http://rubyforge.org/mailman/listinfo/mongrel-users
