Re: stopping processes, preventing connections

On Mar 17, 2010, at 13:34 , Craig Ringer wrote:

> On 17/03/2010 6:32 PM, Herouth Maoz wrote:
>>
>> On Mar 3, 2010, at 18:01 , Josh Kupershmidt wrote:
>>
>>> Though next time you see a query which doesn't respond to
>>> pg_cancel_backend(), try gathering information about the query and
>>> what the backend is doing; either you're doing something unusual (e.g.
>>> an app is restarting the query automatically after getting canceled)
>>> or perhaps you've stumbled on a bug in Postgres.
>>
>> Hi. A long time has passed since you made that suggestion, but today we
>> stumbled again on a query that wouldn't be canceled. Not only does it
>> not respond to pg_cancel_backend(), it also doesn't respond to kill
>> -SIGTERM.
>
> Interesting. If you attach gdb to the backend and run "backtrace", what's the output?

(gdb) backtrace
#0 0x8dfcb410 in ?? ()
#1 0xbff10a28 in ?? ()
#2 0x083b1bf4 in ?? ()
#3 0xbff10a00 in ?? ()
#4 0x8db98361 in send () from /lib/tls/i686/cmov/libc.so.6
#5 0x08195d54 in secure_write ()
#6 0x0819dc7e in pq_setkeepalivesidle ()
#7 0x0819ddd5 in pq_flush ()
#8 0x0819de3d in pq_putmessage ()
#9 0x0819fa63 in pq_endmessage ()
#10 0x08086dcb in printtup_create_DR ()
#11 0x08178dc4 in ExecutorRun ()
#12 0x08222326 in PostgresMain ()
#13 0x082232c0 in PortalRun ()
#14 0x0821e27d in pg_parse_query ()
#15 0x08220056 in PostgresMain ()
#16 0x081ef77f in ClosePostmasterPorts ()
#17 0x081f0731 in PostmasterMain ()
#18 0x081a0484 in main ()

>
> If you strace the backend, what do you see?

All I get is this:
send(9, "00:00\0\0\0\0011\377\377\377\377\0\0\0\0011\0\0\0\0041"..., 1541, 0

I waited about 20 minutes after receiving that, but nothing further was output.

Thank you,
Herouth