Thread: Fatal process interaction
The situation: In xterm #1: psql running, connected to database pssdb, executing an SQL select statement. In xterm #2: A shell script is run that pipes another select statement throug psql. When the select statement in xterm #2 completes, the select statement being executed in xterm #1 aborts and the following error message is output: NOTICE: Message from PostgreSQL backend: The Postmaster has informed me that some other backend died abnormally and possibly corrupted shared memory. I have rolled back the current transaction and am going to terminate your database system connection and exit. Please reconnect to the database system and repeat your query. pqReadData() -- backend closed the channel unexpectedly. This probably means the backend terminated abnormally beforeor while processing the request. We have lost the connection to the backend, so further processing is impossible. Terminating. This problem is very repeatable and does not seem to depend on which UID is running which session. They can both be postgres, or me (smw) or one of each. The one common factor appears to be that psql is involved in both. If psql is run in interactive mode in both windows, then \q is issued in one of the windows, both psql sessions will terminate. Any ideas? -- Steven M. Wheeler UNIX Engineering The SABRE Group (918) 292-4119 (918) 292-4165 FAX
"Steven M. Wheeler" <swheeler@sabre.com> writes: > If psql is run in interactive mode in both windows, then \q is issued > in one of the windows, both psql sessions will terminate. Wow, that's pretty bizarre. What platform are you on? I think the FAQ mentions that problems like this have been seen on systems where SysV semaphore support wasn't configured or didn't work right ... regards, tom lane
More info. Motivated by your remark about SysV semaphores, I upgraded the kernel to 2.0.36 and the problem appears to have gone away. -- Steven M. Wheeler UNIX Engineering The SABRE Group (918) 292-4119 (918) 292-4165 FAX Tom Lane wrote: > "Steven M. Wheeler" <swheeler@sabre.com> writes: > > If psql is run in interactive mode in both windows, then \q is issued > > in one of the windows, both psql sessions will terminate. > > Wow, that's pretty bizarre. What platform are you on? I think the FAQ > mentions that problems like this have been seen on systems where SysV > semaphore support wasn't configured or didn't work right ... > > regards, tom lane
"Steven M. Wheeler" <swheeler@sabre.com> writes: > More info. Motivated by your remark about SysV semaphores, I upgraded the > kernel to 2.0.36 and the problem appears to have gone away. You know, you're the second person in the past few months who has reported strange problems that stopped after a kernel upgrade. Which Linux version were you on before? This definitely needs to go in the FAQ, I think... regards, tom lane
This system was originally configured from Slackware 3.6, kernel 2.0.35. Tom Lane wrote: > "Steven M. Wheeler" <swheeler@sabre.com> writes: > > More info. Motivated by your remark about SysV semaphores, I upgraded the > > kernel to 2.0.36 and the problem appears to have gone away. > > You know, you're the second person in the past few months who has > reported strange problems that stopped after a kernel upgrade. > Which Linux version were you on before? This definitely needs to > go in the FAQ, I think... > > regards, tom lane -- Steven M. Wheeler UNIX Engineering The SABRE Group (918) 292-4119 (918) 292-4165 FAX