On Thu, May 19, 2016 at 09:58:45AM -0400, Tom Lane wrote: > "ktm@xxxxxxxx" <ktm@xxxxxxxx> writes: > > I am investigating a problem with a backend that appears to be stuck > > and spinning while performing a "DISCARD ALL" command. The system is > > running an older release 9.2.2. > > You do realize that the current release in that series is 9.2.17. > > > Are there any bugs that could be causing this behavior? > > Known bugs are summarized here: > http://www.postgresql.org/docs/9.2/static/release.html > > > How can I tell what the process is actually doing? > > Getting a stack trace with gdb might be informative: > https://wiki.postgresql.org/wiki/Generating_a_stack_trace_of_a_PostgreSQL_backend > > regards, tom lane > Hi, The stack trace just appeared to be what I would expect while a 'DISCARD ALL' command was being run: Continuing. Program received signal SIGINT, Interrupt. 0x000000000073bc7c in MemoryContextSetParent () #0 0x000000000073bc7c in MemoryContextSetParent () #1 0x000000000073bde3 in MemoryContextDelete () #2 0x000000000054e3a9 in DropAllPreparedStatements () #3 0x00000000005365f3 in DiscardCommand () #4 0x00000000006582c7 in ?? () #5 0x00000000006592bd in ?? () #6 0x0000000000659a42 in PortalRun () #7 0x000000000065603d in ?? () #8 0x0000000000656ed0 in PostgresMain () #9 0x0000000000613b91 in ?? () #10 0x00000000006167fc in PostmasterMain () #11 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000073bc7c in MemoryContextSetParent () #0 0x000000000073bc7c in MemoryContextSetParent () #1 0x000000000073bde3 in MemoryContextDelete () #2 0x000000000054e3a9 in DropAllPreparedStatements () #3 0x00000000005365f3 in DiscardCommand () #4 0x00000000006582c7 in ?? () #5 0x00000000006592bd in ?? () #6 0x0000000000659a42 in PortalRun () #7 0x000000000065603d in ?? () #8 0x0000000000656ed0 in PostgresMain () #9 0x0000000000613b91 in ?? () #10 0x00000000006167fc in PostmasterMain () #11 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000073bc7c in MemoryContextSetParent () #0 0x000000000073bc7c in MemoryContextSetParent () #1 0x000000000073bde3 in MemoryContextDelete () #2 0x000000000070e7df in DropCachedPlan () #3 0x000000000054e3a9 in DropAllPreparedStatements () #4 0x00000000005365f3 in DiscardCommand () #5 0x00000000006582c7 in ?? () #6 0x00000000006592bd in ?? () #7 0x0000000000659a42 in PortalRun () #8 0x000000000065603d in ?? () #9 0x0000000000656ed0 in PostgresMain () #10 0x0000000000613b91 in ?? () #11 0x00000000006167fc in PostmasterMain () #12 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000073bc7c in MemoryContextSetParent () #0 0x000000000073bc7c in MemoryContextSetParent () #1 0x000000000073bde3 in MemoryContextDelete () #2 0x000000000054e3a9 in DropAllPreparedStatements () #3 0x00000000005365f3 in DiscardCommand () #4 0x00000000006582c7 in ?? () #5 0x00000000006592bd in ?? () #6 0x0000000000659a42 in PortalRun () #7 0x000000000065603d in ?? () #8 0x0000000000656ed0 in PostgresMain () #9 0x0000000000613b91 in ?? () #10 0x00000000006167fc in PostmasterMain () #11 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000070e7ff in DropCachedPlan () #0 0x000000000070e7ff in DropCachedPlan () #1 0x000000000054e3a9 in DropAllPreparedStatements () #2 0x00000000005365f3 in DiscardCommand () #3 0x00000000006582c7 in ?? () #4 0x00000000006592bd in ?? () #5 0x0000000000659a42 in PortalRun () #6 0x000000000065603d in ?? () #7 0x0000000000656ed0 in PostgresMain () #8 0x0000000000613b91 in ?? () #9 0x00000000006167fc in PostmasterMain () #10 0x00000000005b5290 in main () Detaching from program: /usr/pgsql-9.2/bin/postgres, process 38604 Undefined command: "exit". Try "help". Continuing. Program received signal SIGINT, Interrupt. 0x000000000070e7ff in DropCachedPlan () #0 0x000000000070e7ff in DropCachedPlan () #1 0x000000000054e3a9 in DropAllPreparedStatements () #2 0x00000000005365f3 in DiscardCommand () #3 0x00000000006582c7 in ?? () #4 0x00000000006592bd in ?? () #5 0x0000000000659a42 in PortalRun () #6 0x000000000065603d in ?? () #7 0x0000000000656ed0 in PostgresMain () #8 0x0000000000613b91 in ?? () #9 0x00000000006167fc in PostmasterMain () #10 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000070e7ff in DropCachedPlan () #0 0x000000000070e7ff in DropCachedPlan () #1 0x000000000054e3a9 in DropAllPreparedStatements () #2 0x00000000005365f3 in DiscardCommand () #3 0x00000000006582c7 in ?? () #4 0x00000000006592bd in ?? () #5 0x0000000000659a42 in PortalRun () #6 0x000000000065603d in ?? () #7 0x0000000000656ed0 in PostgresMain () #8 0x0000000000613b91 in ?? () #9 0x00000000006167fc in PostmasterMain () #10 0x00000000005b5290 in main () Continuing. Program received signal SIGINT, Interrupt. 0x000000000073bc7c in MemoryContextSetParent () #0 0x000000000073bc7c in MemoryContextSetParent () #1 0x000000000073bde3 in MemoryContextDelete () #2 0x000000000070e7df in DropCachedPlan () #3 0x000000000054e3a9 in DropAllPreparedStatements () #4 0x00000000005365f3 in DiscardCommand () #5 0x00000000006582c7 in ?? () #6 0x00000000006592bd in ?? () #7 0x0000000000659a42 in PortalRun () #8 0x000000000065603d in ?? () #9 0x0000000000656ed0 in PostgresMain () #10 0x0000000000613b91 in ?? () #11 0x00000000006167fc in PostmasterMain () #12 0x00000000005b5290 in main () Continuing. Does a DISCARD command take alot of time, or is it like TRUNCATE? The backend does have a very large memory footprint (12GB). Regards, Ken -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
