Обсуждение: Difference between terminate/cancel?
Hi!
What is the difference between both? cancel sends QUIT while terminate sends TERM, but what effect does this have on the backends, shared memory, etc?
I had some processes stuck in IDLE in transaction after a machine died (through pgbouncer), and cancel did not close the connections, while terminate did kill the transactions.
The docs at http://www.postgresql.org/docs/9.1/static/functions-admin.html#FUNCTIONS-ADMIN-SIGNAL-TABLE do name the signals, but I can't find other documentation on the effects of TERM/QUIT (I'm on 9.1, but devel says the same thing).
Are there pointers in the docs on the differences?
Thanks!
François
Вложения
François Beausoleil <francois@teksol.info> wrote: > What is the difference between both? > I had some processes stuck in IDLE in transaction after a machine > died (through pgbouncer), and cancel did not close the > connections, while terminate did kill the transactions. > The docs at > http://www.postgresql.org/docs/9.1/static/functions-admin.html#FUNCTIONS-ADMIN-SIGNAL-TABLE > [...] According to the docs you cite: pg_cancel_backend(): Cancel a backend's current query pg_terminate_backend(): Terminate a backend A connection which is idle or idle in transaction does not have a current query to cancel, but it has a backend process which can be terminated. -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
Le 2013-08-13 à 13:25, Kevin Grittner a écrit : > François Beausoleil <francois@teksol.info> wrote: > >> What is the difference between both? > >> I had some processes stuck in IDLE in transaction after a machine >> died (through pgbouncer), and cancel did not close the >> connections, while terminate did kill the transactions. > >> The docs at >> http://www.postgresql.org/docs/9.1/static/functions-admin.html#FUNCTIONS-ADMIN-SIGNAL-TABLE >> [...] > > According to the docs you cite: > > pg_cancel_backend(): Cancel a backend's current query > pg_terminate_backend(): Terminate a backend > > A connection which is idle or idle in transaction does not have a > current query to cancel, but it has a backend process which can be > terminated. Oh, interesting! Now I understand better. Extracted like that, it's obvious what the difference is. Thanks! François