From: Nagaura, Ryohei [mailto:nagaura.ryohei@jp.fujitsu.com]
> > Maybe. Could you suggest good description?
> Clients wait until the socket become readable when they try to get results
> of their query.
> If the socket state get readable, clients read results.
> (See src/interfaces/libpq/fe-exec.c, fe-misc.c)
> The current pg uses poll() to monitor socket states.
> "socket_timeout" is used as timeout argument of poll().
> (See [1] about poll() and its arguments)
>
> Because "tcp_user_timeout" handles the timeout before and after the above
> procedure,
> there are different monitoring target between "socket_timeout" and
> "tcp_user_timeout".
> When the server is saturated, "statement_timeout" doesn't work while
> "socket_timeout" does work.
> In addition to this, the purpose of "statement_timeout" is to reduce
> server's burden, I think.
OK, I understand your intent. What I asked Kirk-san is to suggest a description for socket_timeout parameter that the
userwould see in PostgreSQL documentation.
> My proposal is to enable clients to release their resource which is used
> communication w/ the saturated server.
I thought the primary purpose is to prevent applications from hanging too long, so that the user does not have to wait
infinitely. Releasing resources is a secondary purpose.
Regards
Takayuki Tsunakawa
