Re: [HACKERS] posmaster failed under high load

On Wed, 5 May 1999, Tom Lane wrote:

> Date: Wed, 05 May 1999 09:33:14 -0400
> From: Tom Lane <tgl@sss.pgh.pa.us>
> To: Oleg Bartunov <oleg@sai.msu.su>
> Cc: hackers@postgreSQL.org
> Subject: Re: [HACKERS] posmaster failed under high load 
> 
> Oleg Bartunov <oleg@sai.msu.su> writes:
> > That's why I noticed 10 or more (postmaster) processes, which eventually
> > gone after 30-40 minutes.
> 
> Could those be new backends that have been forked off the main
> postmaster, but haven't yet gotten around to changing their ps info?
> I'm not sure what would block a new backend for many minutes before
> it did that, however.  Can you attach to one of these processes with
> a debugger and get a backtrace to show what it's doing?

Well,

http_load -r 40 -f 240 MASON-DBI
results:
244 fetches, 1020 max parallel, 272060 bytes, in 52 seconds
1115 mean bytes/connection
4.69231 fetches/sec, 5231.92 bytes/sec

Below some output from ps and attached backtrace of one postmaster
process.
Regards,
    Oleg

PS.
Will see what happens with those (postmasters)

18:08[om]:~/app/www/http_load>w 6:09pm  up  1:44,  3 users,  load average: 44.92, 18.56, 7.08

18:08[om]:/usr/local/etc/httpd/conf>psg post  76  ?  S    0:00 postmaster -i -B 1024 -S -D/usr/local/pgsql/data/ -o -Fe
602  ?  SW   0:00 (postmaster) 634  ?  D    0:00 /usr/local/pgsql/bin/postgres localhost httpd apod idle  644  ?  SW
0:00(postmaster) 646  ?  SW   0:00 (postmaster) 648  ?  SW   0:00 (postmaster) 650  ?  SW   0:00 (postmaster) 651  ?
SW  0:00 (postmaster) 652  ?  SW   0:00 (postmaster) 653  ?  SW   0:00 (postmaster) 661  ?  SW   0:00 (postmaster) 662
? D    0:00 (postmaster) 663  ?  SW   0:00 (postmaster) 664  ?  SW   0:00 (postmaster) 665  ?  D    0:00 (postmaster)
666 ?  D    0:00 /usr/local/pgsql/bin/postgres localhost httpd apod idle 
 
18:08[om]:/usr/local/etc/httpd/conf>psg post  76  ?  S    0:00 postmaster -i -B 1024 -S -D/usr/local/pgsql/data/ -o -Fe
651  ?  SW   0:00 (postmaster) 693  ?  SW   0:00 (postmaster) 694  ?  SW   0:00 (postmaster) 698  ?  S    0:00
/usr/local/pgsql/bin/postgreslocalhost httpd apod idle  699  ?  SW   0:00 (postmaster) 700  ?  S    0:00
/usr/local/pgsql/bin/postgreslocalhost httpd apod idle  701  ?  SW   0:00 (postmaster) 702  ?  SW   0:00 (postmaster)
 
18:31[om]:/usr/local/etc/httpd/conf>psg post  76  ?  S    0:00 postmaster -i -B 1024 -S -D/usr/local/pgsql/data/ -o -Fe
651  ?  SW   0:00 (postmaster) 693  ?  SW   0:00 (postmaster) 694  ?  SW   0:00 (postmaster) 698  ?  S    0:00
/usr/local/pgsql/bin/postgreslocalhost httpd apod idle  699  ?  SW   0:00 (postmaster) 700  ?  S    0:00
/usr/local/pgsql/bin/postgreslocalhost httpd apod idle  701  ?  SW   0:00 (postmaster) 702  ?  SW   0:00 (postmaster)
 
18:34[om]:/usr/local/etc/httpd/conf>

om:~$ gdb 702
GDB is free software and you are welcome to distribute copies of itunder certain conditions; type "show copying" to see
theconditions.
 
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.16 (i486-slackware-linux), 
Copyright 1996 Free Software Foundation, Inc...

702: No such file or directory.

(gdb) q
om:~$ gdb /usr/local/pgsql/bin/postmaster 702
GDB is free software and you are welcome to distribute copies of itunder certain conditions; type "show copying" to see
theconditions.
 
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.16 (i486-slackware-linux), 
Copyright 1996 Free Software Foundation, Inc...

/u/postgres/702: No such file or directory.
Attaching to program /usr/local/pgsql/bin/postmaster', process 702
Reading symbols from /lib/libdl.so.1...done.
Reading symbols from /lib/libm.so.5...done.
Reading symbols from /lib/libtermcap.so.2...done.
Reading symbols from /lib/libc.so.5...done.
Reading symbols from /lib/ld-linux.so.1...done.
0x40081464 in recv (sockfd=0, buffer=0xbfffa394, len=3221224256,    flags=135555648)
(gdb) bt
#0  0x40081464 in recv (sockfd=0, buffer=0xbfffa394, len=3221224256,    flags=135555648)
#1  0x400a58e8 in __DTOR_END__ ()
#2  0x80a2585 in pq_getbytes ()
#3  0x80e1ed8 in SocketBackend ()
#4  0x80e1f66 in ReadCommand ()
#5  0x80e350c in PostgresMain ()
#6  0x80ccf2a in DoBackend ()
#7  0x80cca5b in BackendStartup ()
#8  0x80cc1d7 in ServerLoop ()
#9  0x80cbd63 in PostmasterMain ()
#10 0x80a3059 in main ()
#11 0x806121e in _start ()
(gdb) 


> 
>             regards, tom lane
> 

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83