Darren,
On Feb 24, 2011, at 7:04 PM, Darren Nickerson wrote:
That FD is a network connection to our database server:
[root@rt4 Plack-0.9970]# ls -l /proc/30310/fd/1
lrwx------. 1 root root 64 Feb 24 17:44 /proc/30310/fd/1 -> socket:
[281592]
[root@rt4 Plack-0.9970]# netstat -antep | grep 281592
tcp 0 5 10.0.12.149:49410
10.0.11.100:3306 ESTABLISHED 48 281592 30310/
httpd
The database server has no record of that tcp connection any
longer, and mysqladmin processlist shows all threads sleeping.
*bump* any thoughts on this?
Should I be looking outiside of RT for a fix for this? Is this more
likely to be a kernel/networking problem in RHEL6 or with mod_perl
or the MySQL DBD/DBI stuff? Looks like RT is using persistent
database connections, but that when the lockup occurs it's usually
because apache is waiting to get data back from a MySQL socket that
no longer exists on the database server ...
It seems the issue is with apache2 and plack. i can reproduce the
stalled connection (however not always) with the
plack-req.psgi example from the plack dist, with apache 2.2.16 on
ubuntu maverick. however it's a bit different from yours.
strace says:
close(0) = 0
read(5, 0x7fffff1f67af, 1) = -1 EAGAIN (Resource
temporarily unavailable)
accept(4, {sa_family=AF_INET, sin_port=htons(64924),
sin_addr=inet_addr("114.44.215.78")}, [16]) = 0
fcntl(0, F_GETFD) = 0
fcntl(0, F_SETFD, FD_CLOEXEC) = 0
getsockname(0, {sa_family=AF_INET, sin_port=htons(6254),
sin_addr=inet_addr("10.130.158.43")}, [16]) = 0
fcntl(0, F_GETFL) = 0x2 (flags O_RDWR)
fcntl(0, F_SETFL, O_RDWR|O_NONBLOCK) = 0
read(0, 0x7f8e98b0bf58, 8000) = -1 EAGAIN (Resource
temporarily unavailable)
poll([{fd=0, events=POLLIN}], 1, 300000
Cheers,
CLK
