Consolidate the configuration checks carried out when cloning
a standby, and enable them to be run separately to check the
required configuration without running STANDBY CLONE multiple times.
Merge basically identical checks in multiple places into a single
function. Only doing this in repmgr, as repmgrd only performs
the version check in one place and we'd need to somehow pass progname
to the function as well, which isn't worth the effort.
Use the reported `server_version_num` integer for version number
detection and comparison. This makes it easier to set an arbitrary
minimum supported version (rather than "9.0 or later") as well
as future-proofing for 10.x and later.
Previously repmgr passed the -W flag to initdb, which forced
manual input of a password; this option removes the -W flag
to make repetitive testing easier.
Previously the witness database creation code was hard-coding the
username 'postgres' when accessing the previously initialised database.
However initdb was not passed any explicit username, meaning the
default database superuser name was the same as the user running
repmgr.
With this patch, a superuser user name (default: postgres) will
be passed to initdb.
Per report by eggyknap [1]
[1] https://github.com/2ndQuadrant/repmgr/issues/38
we have to assume it's the DEFAULT_MASTER_PORT.
This was not done, so we added a check to see if it has a value that is
usable, else we use DEFAULT_MASTER_PORT.
Using '--exclude=dirname/*' to explicitly specify directories whose contents
should not be copied. This will result in empty directories being created
on the destination if they exist on the source, but that's not a problem as
they are needed anyway.
Previously the generated rsync command contained '--exclude=pg_log*', which
will break replication on 9.5 as the wildcard expansion prevents the
'pg_logical' directory from being copied.
While reading node entries from master use a separate PGresult when inserting into witness.
Witness monitoring supplies a null value for 'last_apply_time'.
repmgr repl_status had the column time_lag which was documented to be
the time a standby is behind master. In fact it only works like this
when viewed on the standby and not on the master: there it only was the
time of the last status update. We dropped that column and replaced it
by a new column „communication_time_lag“ which is the content of the
repl_status column on the master. On the standby we contain the time of
the last update in shared mem though refer always to the correct time
nonetheless where repl_status is queried. We also added a new column,
„replication_time_lag“, which refers to the apply delay.
