On Thu, May 25, 2017 at 11:41:19AM +0900, Michael Paquier wrote: > On Thu, May 25, 2017 at 11:34 AM, Tsunakawa, Takayuki > <tsunakawa.ta...@jp.fujitsu.com> wrote: > > From: pgsql-hackers-ow...@postgresql.org > >> [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Noah Misch > >> Ten feels low to me. The value should be be low enough so users don't give > >> up and assume a permanent hang, but there's little advantage to making it > >> lower. > >> I'd set it such that we give up in 1-5s on a modern Windows machine, which > >> I expect implies a retry count of one hundred or more. > > > > Then, maybe we can measure the time in each iteration and give up after a > > particular seconds.
Exact duration is not important. Giving up after 0.1s is needlessly early, because a system taking that long to start a backend is still usable. Giving up after 50s is quite late. In between those extremes, lots of durations would be reasonable. Thus, measuring time is needless complexity; retry count is a suitable proxy. > Indeed, pgrename() does so with a 100ms sleep time between each > iteration. Perhaps we could do that and limit to 50 iterations? pgrename() is polling for an asynchronous event, hence the sleep. To my knowledge, time doesn't heal shm attach failures; therefore, a sleep is not appropriate here. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
