El día Montag, April 27, 2020 a las 08:40:04 -0400, Tom Lane escribió: > Matthias Apitz <guru@xxxxxxxxxxx> writes: > > I encounter from time to time that one of our ESQL/C clients hangs with > > the details described below for ever, while accessing on startup a table > > 'sisisinst' which has only some 50 rows, all of CHAR columns. Other ESQL/C clients > > start up fine (they all check this table 'sisisinst' on startup to > > verify the correct version of our application) Also SQL works > > fine. > > > What can I do to get to the source of the problem? Thanks > > Can you get a stack trace from the connected backend? Or even just look > at what it's doing according to pg_stat_activity? (If it's a reasonably > modern server, the wait-condition fields would be interesting.) srap32dxr1:/opt/lib/sisis/catserver/bin # lsof -P | grep 53742 INDEX 23957 sisis 2u IPv6 117475261 0t0 TCP localhost:53742->localhost:5432 (ESTABLISHED) postmaste 23958 postgres 9u IPv6 117478789 0t0 TCP localhost:5432->localhost:53742 (ESTABLISHED) 'INDEX' is the hanging proc; PID 23958 its server; gdb shows: # gdb /usr/local/sisis-pap/pgsql/bin/postgres 23958 ... (gdb) bt #0 0x00007fd567776000 in epoll_pwait () from /lib64/libc.so.6 #1 0x000000000084476c in WaitEventSetWaitBlock () #2 0x0000000000844647 in WaitEventSetWait () #3 0x00000000006f89d2 in secure_read () #4 0x0000000000707425 in pq_recvbuf () #5 0x0000000000707709 in pq_discardbytes () #6 0x0000000000707aba in pq_getmessage () #7 0x000000000086b478 in SocketBackend () #8 0x000000000086b4c4 in ReadCommand () #9 0x000000000086fda9 in PostgresMain () #10 0x00000000007dde15 in BackendRun () #11 0x00000000007dd595 in BackendStartup () #12 0x00000000007d9c9b in ServerLoop () #13 0x00000000007d9556 in PostmasterMain () #14 0x000000000070e2a5 in main () sisis=# select * from pg_stat_activity where client_port = 53742; datid | datname | pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | xact_start | query_start | state_change | wait_event_type | wait_event | state | backend_xid | backend_xmin | query | backend_type 93831 | sisis | 23958 | 16384 | sisis | | ::1 | | 53742 | 27.04.2020 12:37:46.941441 CEST | | | 27.04.2020 12:37:46.943073 CEST | Client | ClientRead | idle | | | | client backend (1 Zeile) HIH && Kinde Regards matthias -- Matthias Apitz, ✉ guru@xxxxxxxxxxx, http://www.unixarea.de/ +49-176-38902045 Public GnuPG key: http://www.unixarea.de/key.pub May, 9: Спаси́бо освободители! Thank you very much, Russian liberators!
