On Wed, May 3, 2017 at 6:28 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > On 23 April 2017 at 01:10, Petr Jelinek <petr.jeli...@2ndquadrant.com> wrote: >> Hi, >> >> The time based lag tracking commit [1] added interface for logging >> progress of replication so that we can report lag as time interval >> instead of just bytes. But the patch didn't contain patch for the >> builtin logical replication. >> >> So I wrote something that implements this. I didn't like all that much >> the API layering in terms of exporting the walsender's LagTrackerWrite() >> for use by plugin directly. Normally output plugin does not have to care >> if it's running under walsender or not, it uses abstracted write >> interface for that which can be implemented in various ways (that's how >> we implement SQL interface to logical decoding after all). So I decided >> to add another function to the logical decoding write api called >> update_progress and call that one from the output plugin. The walsender >> then implements that new API to call the LagTrackerWrite() while the SQL >> interface just does not implement it at all. This seems like cleaner way >> of doing it. >> >> Thoughts? > > Agree cleaner.
+1 > I don't see any pacing or comments about it, nor handling of > intermediate messages while we process a large transaction. > > I'll look at adding some pacing code in WalSndUpdateProgress() By the way, I have a small improvement to the interpolation to propose. Right now, after a period of idleness it can report a silly large number based on an ancient time, but you won't usually see it because it's quickly replaced by a sensible number. I think this thinko will affect logical rep with Petr's patch more. I had been meaning to post the improvement but got sidetracked by that recovery test failure problem. I'll post that in the next few days. -- Thomas Munro http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
