The warning emitted gives the impression that monitoring data shouldn't
be written if there's no streaming replication, but we can and should
do this as long as we have a primary connection.
Explictly document this in the code.
Also remove an unused variable warning.
It must never contain "repmgr standby promote", as it is intended
to enable use of package-level promote commands such as Debian's
"pg_ctlcluster promote".
Addresses GitHub #336.
The string in question will be generated internally by repmgr as a simple
one-line string with no control characters etc., so all that needs to be
escaped at the moment are any double quotes.
If repmgrd is monitoring a primary which is taken off-line, then later
restored as a standby, detect this change and resume monitoring
in standby node.
Addresses GitHub #338.
All disconnected nodes will be in a static, known state, so as long as
each node has the same meta-information (repmgr.nodes) and is able
to retrieve the last receive LSN of the other nodes, it is possible
for each node to independently determine the best promotion candidate,
thereby reaching consensus without an explicit "voting" process.
get_new_primary() returns NULL if no notification for the new primary has
been received, but the code was expecting it to return UNKNOWN_NODE_ID,
which was causing repmgrd to prematurely drop out of the new primary
detection loop if no notification had been received by the time the loop
started.
Also store the electoral term as a single row, single column table,
to ensure that all repmgrds see the same turn. It is then bumped
by the winning node after it gets promoted.
Various logging improvements.
The standby may not always be available for connections right after it's
restarted, so attempting to connect and get the node's upstream record
after the restart may fail. Record is now retrieved before the restart.
Addresses GitHub #333.
