Re: [HACKERS] Broken system timekeeping breaks the stats collector

2012-06-17 Thread Simon Riggs
On 17 June 2012 08:26, Tom Lane t...@sss.pgh.pa.us wrote: (1) In backend_read_statsfile, make an initial attempt to read the stats file and then read GetCurrentTimestamp after that.  If the local clock reading is less than the stats file's timestamp, we know that some sort of clock skew or

Re: [HACKERS] Broken system timekeeping breaks the stats collector

2012-06-17 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: Fine, but please log this as a WARNING system time skew detected, so we can actually see it has happened rather than just silently accepting the situation. I think elog(LOG) is more appropriate, same as we have for the existing messages for related

[HACKERS] Broken system timekeeping breaks the stats collector

2012-06-16 Thread Tom Lane
I've had a vague feeling for awhile now that the occasional buildfarm failures we see in the stats regression test (where it appears that the stats collector fails to respond to requests for no good reason) might be related to operating-system timekeeping glitches. Today there is finally

Re: [HACKERS] Broken system timekeeping breaks the stats collector

2012-06-16 Thread Dickson S. Guedes
2012/6/16 Tom Lane t...@sss.pgh.pa.us: [... cut ...] (1) In backend_read_statsfile, make an initial attempt to read the stats file and then read GetCurrentTimestamp after that.  If the local clock reading is less than the stats file's timestamp, we know that some sort of clock skew or glitch

Re: [HACKERS] Broken system timekeeping breaks the stats collector

2012-06-16 Thread Tom Lane
Dickson S. Guedes lis...@guedesoft.net writes: What happens when Daylight saving time ends? Or it doesn't matter in this scenario? Irrelevant, we're working in UTC-based timestamps. regards, tom lane -- Sent via pgsql-hackers mailing list