Re: postmaster hangs

sorry ,but i had to go with my job so i have killed one of the backends
and this made the post restart.
However befor this i have done another backtrace ,the one that was hang
in the middle of SELECT (not startup)
and got this:
#0  0xffffe410 in ?? ()
#1  0xbfffcf08 in ?? ()
#2  0x00000001 in ?? ()
#3  0x01490006 in ?? ()
#4  0x402ffffb in semop () from /lib/tls/libc.so.6
#5  0x08154d07 in PGSemaphoreLock ()
#6  0x08177ade in LWLockAcquire ()
#7  0x0816c7f2 in ReadBufferInternal ()
#8  0x08086eb0 in _bt_getbuf ()
#9  0x080882b6 in _bt_getroot ()
#10 0x0808ab62 in _bt_search ()
#11 0x0808aeca in _bt_first ()
#12 0x080894e0 in btgettuple ()
#13 0x081eba7b in FunctionCall2 ()
#14 0x08083f86 in index_getnext ()
#15 0x081174a0 in IndexNext ()
#16 0x0811139f in ExecScan ()
#17 0x081173c8 in ExecIndexScan ()
#18 0x0810d34d in ExecProcNode ()
#19 0x0810b9ef in ExecutorRun ()
#20 0x0817f7f3 in PortalRunSelect ()
#21 0x08180507 in PortalRun ()
#22 0x0817c5b4 in exec_simple_query ()
#23 0x0817e4d3 in PostgresMain ()
#24 0x08157754 in ServerLoop ()
#25 0x08158d1e in PostmasterMain ()
#26 0x08128c21 in main ()
I did not understand from your message wheither this is a problem in pg
or in application.
The exact version of pg is postgres (PostgreSQL) 7.4.8.
Thanks.
Tom Lane wrote:

>Tsirkin Evgeny <tsurkin@mail.jct.ac.il> writes:
>
>
>>Today i was trying to run an old ver. of an application on test server .
>>After a while i have got the pg hangs :
>>
>>
>
>It looks like someone is holding a critical LWLock --- hard to tell if
>it's the BufMgrLock or a per-buffer lock for a system index's metapage,
>but must be one or the other.  Try backtracing the processes that
>*aren't* hung in this particular way.  I'm not sure you'll be able to
>learn anything much given that the build doesn't have debug info, but
>you might as well try.
>
>            regards, tom lane
>
>