Re: WAL insert delay settings

On Wed, Feb 13, 2019 at 4:16 AM Peter Eisentraut
<peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
> Bulk operations like CREATE INDEX, ALTER TABLE, or bulk loads can create
> a lot of WAL. A lot of WAL at once can cause delays in replication.
> For synchronous replication, this can make seemingly unrelated sessions
> hang. But also for asynchronous replication, it will increase latency.

I think that I suggested a feature like this early during my time at
Heroku, about 5 years ago. There would occasionally be cases where ops
would find it useful to throttle WAL writing using their own terrible
kludge (it involved sending SIGSTOP to the WAL writer).

I recall that this idea was not well received at the time. I still
think it's a good idea, though. Provided there is a safe way to get it
to work.

--
Peter Geoghegan