BUG #7676: pgSocketCheck dosen`t return

yongchao.xu@newtouch.cn writes:

I have this problem today: one thread of our application hung, and
we found the thread waiting for the result of poll() function. poll()
was called by pgSocketCheck(). So is it a bug of pg?

So far as anyone can tell, this trace just indicates that the
application is waiting for a response from the server. If there's
a bug there, you'd need to provide more or different information to
prove it. I think more likely you need to be consulting
http://wiki.postgresql.org/wiki/Slow_Query_Questions

regards, tom lane

On Monday, November 19, 2012 11:31 AM yongchao.xu@newtouch.cn wrote:

The following bug has been logged on the website:

Bug reference: 7676
Logged by: yonchao
Email address: yongchao.xu@newtouch.cn
PostgreSQL version: 8.4.6
Operating system: CentOS 5.5（64bit）
Description:

I have this problem today: one thread of our application hung, and
we found the thread waiting for the result of poll() function. poll()
was called by pgSocketCheck(). So is it a bug of pg? I found the bug
report from
website(http://archives.postgresql.org/pgsql-bugs/2008-02/msg00260.php),
and want to know:

1. Has this problem been solved in the newest version?
2. If not, what shall I do to avoid this problem?

Thanks a lot!

PS:
gdb info:
(gdb) bt
#0 0x00d31402 in __kernel_vsyscall ()
#1 0x003d3dc3 in poll () from /lib/i686/nosegneg/libc.so.6
#2 0x0013de5d in pqSocketCheck () from /usr/local/pgsql/lib/libpq.so.5
#3 0x0013df8d in pqWaitTimed () from /usr/local/pgsql/lib/libpq.so.5
#4 0x0013e003 in pqWait () from /usr/local/pgsql/lib/libpq.so.5
#5 0x0013d792 in PQgetResult () from /usr/local/pgsql/lib/libpq.so.5

I have also observed similar problem in some of tests, but it appears to be hung due to network break and it came out after 15-20 minutes.

With Regards,
Amit Kapila.