On 1/4/17 2:44 PM, Peter Eisentraut wrote: > On 1/4/17 9:46 AM, Magnus Hagander wrote: >> How about we default max_replication_slots to -1, which means to use the >> same value as max_wal_senders? > >> But you don't necessarily want to adjust them together, do you? They are >> both capped by max_connections, but I don't think they have any other >> direct relation between each other? > > I think the most usual case is that you use approximately one > replication slot per wal sender slot. So it would be a good default to > make them equal.
Well, let's worry about that later. I think everyone is now in agreement with your original change proposal. My suggestion would be to make the defaults of max_wal_senders and max_replication_slots the same, so we don't open an opportunity for ongoing discussions about why they are different and how different they should be. Ideally, we would make max_replication_slots go away at some point similar to my suggestion above. I also suggest making the defaults for both 20 instead of 10. That leaves enough room that almost nobody ever has to change them, whereas 10 can be a bit tight for some not-outrageous installations (8 standbys plus backup?). Your patch looks OK, documentation changes look good. I wouldn't be surprised if we found another place or two that will need updating, but that is not a big deal. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
