On Mon, Jan 30, 2017 at 6:16 PM, Nikolai Zhubr <n-a-zhubr@xxxxxxxxx> wrote: > I'm observing some strange inexplicable effect in 9.5.5 server running on > x86 windows (32-bit windows xp sp3). Oh, well... You are aware that this is out of support by Microsoft, right? > That is, CPU usage in backend process > for the session in question starts to grow, going from approx 0-1 to 8-15 > percent and more, stays that high for several seconds, then goes back to > 0-1. All the effect takes about 15-30 seconds, and repeats stably every > 10-20 minutes (as long as the respective client continues to run the same > queries). Apparently it is essential to consider the pattern of requests > going to the server: in this case there is a continuous stream of very small > cheap queries, but quite a lot of them per second. Trying to understand the > reason, I've managed to craft a pure artifical test triggering very similar > CPU load waves without the need for any specific database at all, easy to > repeat: > > 1. "select localtimestamp" 40 times (As separate requests, one by one, but > no delay inserted in between) > 2. wait 1/2 second. > 3. goto 1 Craig, could this be a side-effect of 519b0757? That's new in 9.5, and that's directly related to the code paths discussed here. -- Michael -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
