On Sun, Sep 6, 2015 at 5:58 PM, Andres Freund <andres@anarazel.de> wrote: > > On 2015-09-04 23:44:21 +0100, Simon Riggs wrote: > > I see the need for both current wait information and for cumulative > > historical detail. > > > > I'm willing to wait before reviewing this, but not for more than 1 more CF. > > > > Andres, please decide whether we should punt to next CF now, based upon > > other developments. Thanks > > I think we can do some of the work concurrently - the whole lwlock > infrastructure piece is rather independent and what currently most of > the arguments are about. I agree that the actual interface will need to > be coordinated. > > Ildus, could you please review Amit & Robert's patch? >
Are you talking about patch where I have fixed few issues in Robert's
patch [1] or the original patch [3] written by me.
1) We fit all information about current wait event into single byte.
2) We put this byte into PgBackendStatus.
Both of these issues are essential for design of [3].
Issue #1 means that we actually can expose to user only event type (until there are less then 256 types) with no parameters [4]. Issue #2 means that we have to monitor only backend not auxiliary processes [5].
Both of these issues seems to be serious limitations for me. It makes me think we either need a different design or need to expose current wait event in some other way additionally. Anyway, I think attracting more attention to this problem is good. It would be very nice if Simon or Andres give review of this.
