Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
Can't describe it much better then that ... I've got it compiled WITH_THREADS and MPM=worker ... starts fine, get a line in /var/log/httpd-error.log: [Tue May 21 10:01:47 2002] [notice] Digest: generating secret for digest authentication ... [Tue May 21 10:01:52 2002] [notice] Digest: done [Tue May 21 10:01:53 2002] [notice] Apache/2.0.36 (Unix) DAV/2 PHP/4.2.1 configured -- resuming normal operations But when I try to connect to the site in question, the connection just hangs there ... as soon as I do a 'stop' of the server, though, the page is sent and then httpd terminates ... I'm running with settings of: IfModule worker.c StartServers 1 MaxClients 128 MinSpareThreads 5 MaxSpareThreads 15 ThreadsPerChild 64 MaxRequestsPerChild 0 /IfModule And am getting no errors that I can find ... ps shows: earth# ps aux | grep http root78796 0.0 0.1 9764 6012 ?? SsJ 10:06AM 0:00.11 /usr/local/sbin/httpd nobody 78799 0.0 0.1 9268 4944 ?? SJ 10:06AM 0:00.01 /usr/local/sbin/httpd nobody 78825 0.0 0.2 15044 6640 ?? IJ 10:06AM 0:00.03 /usr/local/sbin/httpd Which I find kinda odd since I'm not getting that many hits, and told it to only start with one :( Thoughts as to what I should look at here? I've even enabled the 'apache_runtime_status' file, and that appears to make no difference ...
Re: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
Just tried the same config on a seperate FreeBSD machine ... both are running 4.6-PRERELEASE right now, and the problem(s) are the same ... connect, hang, kill server and page gets sent across then server goes down ... On Tue, 21 May 2002, Marc G. Fournier wrote: Can't describe it much better then that ... I've got it compiled WITH_THREADS and MPM=worker ... starts fine, get a line in /var/log/httpd-error.log: [Tue May 21 10:01:47 2002] [notice] Digest: generating secret for digest authentication ... [Tue May 21 10:01:52 2002] [notice] Digest: done [Tue May 21 10:01:53 2002] [notice] Apache/2.0.36 (Unix) DAV/2 PHP/4.2.1 configured -- resuming normal operations But when I try to connect to the site in question, the connection just hangs there ... as soon as I do a 'stop' of the server, though, the page is sent and then httpd terminates ... I'm running with settings of: IfModule worker.c StartServers 1 MaxClients 128 MinSpareThreads 5 MaxSpareThreads 15 ThreadsPerChild 64 MaxRequestsPerChild 0 /IfModule And am getting no errors that I can find ... ps shows: earth# ps aux | grep http root78796 0.0 0.1 9764 6012 ?? SsJ 10:06AM 0:00.11 /usr/local/sbin/httpd nobody 78799 0.0 0.1 9268 4944 ?? SJ 10:06AM 0:00.01 /usr/local/sbin/httpd nobody 78825 0.0 0.2 15044 6640 ?? IJ 10:06AM 0:00.03 /usr/local/sbin/httpd Which I find kinda odd since I'm not getting that many hits, and told it to only start with one :( Thoughts as to what I should look at here? I've even enabled the 'apache_runtime_status' file, and that appears to make no difference ...
Re: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
On Tue, May 21, 2002 at 10:12:17AM -0300, Marc G. Fournier wrote: Just tried the same config on a seperate FreeBSD machine ... both are running 4.6-PRERELEASE right now, and the problem(s) are the same ... connect, hang, kill server and page gets sent across then server goes down ... Same here. And the same probably on every FreeBSD. Try --with-mpm=prefork which works better. AFAIK it is still unclear whether APR is the reason, or rather the somewhat broken pthreads on FreeBSD Most developers think it's the latter. Martin -- [EMAIL PROTECTED] | Fujitsu Siemens Fon: +49-89-636-46021, FAX: +49-89-636-47655 | 81730 Munich, Germany
Re: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
On Tue, May 21, 2002 at 01:14:00PM -0300, Marc G. Fournier wrote: Just to confirm, would it be the following that I'm looking at: ... Nope, further down: * FreeBSD, threads, and worker MPM. All seems to work fine if you only have one worker process with many threads. Add a second worker process and the accept lock seems to be lost. This might be an APR issue with how it deals with the child_init hook (i.e. the fcntl lock needs to be resynced). More examination and analysis is required. Status: This has also been reported on Cygwin. Message-ID: [EMAIL PROTECTED] (cygnus) Justin says: So, FreeBSD-CURRENT and Cywin have the same problem. Yum. If another platform has this with worker, this becomes a showstopper. Aaron says: I spent some time disecting this and have come to the conclusion that it is not a problem in the worker MPM (or at least, it is not isolated to a problem in worker). I'll list some of the problems I'm seeing in case someone else wants to pick up where I've left off: - Delivery of just about any signal to one of the child processes will send it into an infinite loop as well. - Even though the parent is spinning out of control, at first the child or children will appear to work properly. At times it is possible to get it into a state, however, where a request will hang until another concurrent request kicks the first, at which point the second will hang. My theory is that this has to do with the pthread_cond_*() implementation in FreeBSD, but it's still possible that it is in APR. Justin adds: Oh, FreeBSD threads are implemented entirely with select()/poll()/longjmp(). Welcome to the nightmare. So, that means a ktrace output also has the thread scheduling internals in it (since it is all the same to the kernel). Which makes it hard to distinguish between our select() calls and their select() calls. *bangs head on wall repeatedly* But, some of the libc_r files have a DBG_MSG #define. This is moderately helpful when used with -DNO_DETACH. The kernel scheduler isn't waking up the threads on a select(). Yum. And, I bet those decrementing select calls have to do with the scheduler. Time to brush up on our OS fundamentals. -aaron
Re: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
Okay, but this is the scenario that I do want (one worker, many threads) ... so I setup my httpd.conf as: IfModule worker.c StartServers 1 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadsPerChild 25 MaxRequestsPerChild 0 /IfModule But as soon as I start up, it starts 3 servers (I would expect 2 ... one root, one nobody): atelier# ps aux | grep http root 59418 0.0 0.1 1416 1052 ph RV+ 1:41PM 0:00.00 grep http (csh) root 59405 0.0 0.4 5316 3708 ?? Ss1:39PM 0:00.03 /usr/local/sbin/httpd www59406 0.0 0.3 5096 3480 ?? I 1:39PM 0:00.00 /usr/local/sbin/httpd www59409 0.0 0.4 7420 4000 ?? I 1:39PM 0:00.00 /usr/local/sbin/httpd With the second one be a good 50% larger then the other two ... So, am I mis-understanding below, *or*, mis-understanding the conf file ... On Tue, 21 May 2002, Aaron Bannert wrote: On Tue, May 21, 2002 at 01:14:00PM -0300, Marc G. Fournier wrote: Just to confirm, would it be the following that I'm looking at: ... Nope, further down: * FreeBSD, threads, and worker MPM. All seems to work fine if you only have one worker process with many threads. Add a second worker process and the accept lock seems to be lost. This might be an APR issue with how it deals with the child_init hook (i.e. the fcntl lock needs to be resynced). More examination and analysis is required. Status: This has also been reported on Cygwin. Message-ID: [EMAIL PROTECTED] (cygnus) Justin says: So, FreeBSD-CURRENT and Cywin have the same problem. Yum. If another platform has this with worker, this becomes a showstopper. Aaron says: I spent some time disecting this and have come to the conclusion that it is not a problem in the worker MPM (or at least, it is not isolated to a problem in worker). I'll list some of the problems I'm seeing in case someone else wants to pick up where I've left off: - Delivery of just about any signal to one of the child processes will send it into an infinite loop as well. - Even though the parent is spinning out of control, at first the child or children will appear to work properly. At times it is possible to get it into a state, however, where a request will hang until another concurrent request kicks the first, at which point the second will hang. My theory is that this has to do with the pthread_cond_*() implementation in FreeBSD, but it's still possible that it is in APR. Justin adds: Oh, FreeBSD threads are implemented entirely with select()/poll()/longjmp(). Welcome to the nightmare. So, that means a ktrace output also has the thread scheduling internals in it (since it is all the same to the kernel). Which makes it hard to distinguish between our select() calls and their select() calls. *bangs head on wall repeatedly* But, some of the libc_r files have a DBG_MSG #define. This is moderately helpful when used with -DNO_DETACH. The kernel scheduler isn't waking up the threads on a select(). Yum. And, I bet those decrementing select calls have to do with the scheduler. Time to brush up on our OS fundamentals. -aaron
RE: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
From: Marc G. Fournier [mailto:[EMAIL PROTECTED]] Okay, but this is the scenario that I do want (one worker, many threads) ... so I setup my httpd.conf as: IfModule worker.c StartServers 1 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadsPerChild 25 MaxRequestsPerChild 0 /IfModule But as soon as I start up, it starts 3 servers (I would expect 2 ... one root, one nobody): atelier# ps aux | grep http root 59418 0.0 0.1 1416 1052 ph RV+ 1:41PM 0:00.00 grep http (csh) root 59405 0.0 0.4 5316 3708 ?? Ss1:39PM 0:00.03 /usr/local/sbin/httpd www59406 0.0 0.3 5096 3480 ?? I 1:39PM 0:00.00 /usr/local/sbin/httpd www59409 0.0 0.4 7420 4000 ?? I 1:39PM 0:00.00 /usr/local/sbin/httpd With the second one be a good 50% larger then the other two ... So, am I mis-understanding below, *or*, mis-understanding the conf file ... Did you configure cgi? If so, one of those two processes owned by www is the CGId process. Ryan
Re: Apache 2.0.36 w/ FreeBSD ... 'hangs' ...
On Tue, 21 May 2002, Marc G. Fournier wrote: Okay, I had heard that the 'broken pthreads' was something that was fixed since 4.5 ... are you saying that this isn't the case? :( Going to threads was one of my key reasons for moving to Apache2 :( It's unclear from http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libc_r/uthread/uthread_sendfile.c whether or not the problem is fixed in 4.6PRERELEASE, unless that is strictly based off of HEAD. There's no tag in that file for it. Changes definitely went in after 4.5 that would affect this problem. --Cliff -- Cliff Woolley [EMAIL PROTECTED] Charlottesville, VA
