Geo: `checkpoint_segments` is no longer a config option in PostgreSQL 9.5+

The Geo documentation includes the checkpoint_segments option, but this is no longer supported in PostgreSQL 9.5+:

unrecognized configuration parameter "checkpoint_segments" in file "/home/stanhu/gdk-ee/postgresql/data/postgresql.conf" line 66

See: https://www.postgresql.org/docs/9.6/static/release-9-5.html

Replace configuration parameter checkpoint_segments with min_wal_size and max_wal_size (Heikki Linnakangas)

If you previously adjusted checkpoint_segments, the following formula will give you an approximately equivalent setting:

max_wal_size = (3 * checkpoint_segments) * 16MB Note that the default setting for max_wal_size is much higher than the default checkpoint_segments used to be, so adjusting it might no longer be necessary.

We should figure out how to handle this for GitLab 9.0, since it will default to PostgreSQL 9.6.

/cc: @brodock, @rspeicher, @dbalexandre, @marin, @ibaum

added ~164929 label

We currently account for this in the postgresql.conf template in the omnibus chef cookbook:

<% if pg_helper.database_version == "9.2" %>
checkpoint_segments = <%= node['gitlab']['postgresql']['checkpoint_segments'] %>		# in logfile segments, min 1, 16MB each, default 3
<% else %>
min_wal_size = <%= node['gitlab']['postgresql']['min_wal_size'] %>
max_wal_size = <%= node['gitlab']['postgresql']['max_wal_size'] %>
<% end %>

Oh, nice! I was setting this up in my dev environment, so I did not get the benefit of that check.

This is now in the source documentation only: https://docs.gitlab.com/ee/gitlab-geo/database_source.html

mentioned in merge request !1543 (merged)

assigned to @brodock

changed milestone to %9.0

added ~111707 label

closed via merge request !1543 (merged)

mentioned in commit 3233b76a

mentioned in commit 9a1ac5f7