repmgrd
automatic failover
Automatic failover with repmgrd
repmgrd is a management and monitoring daemon which runs
on each node in a replication cluster. It can automate actions such as
failover and updating standbys to follow the new primary, as well as
providing monitoring information about the state of each standby.
repmgrd
cascading replication
cascading replication
repmgrd
repmgrd and cascading replication
Cascading replication - where a standby can connect to an upstream node and not
the primary server itself - was introduced in PostgreSQL 9.2. &repmgr; and
repmgrd support cascading replication by keeping track of the relationship
between standby servers - each node record is stored with the node id of its
upstream ("parent") server (except of course the primary server).
In a failover situation where the primary node fails and a top-level standby
is promoted, a standby connected to another standby will not be affected
and continue working as normal (even if the upstream standby it's connected
to becomes the primary node). If however the node's direct upstream fails,
the "cascaded standby" will attempt to reconnect to that node's parent
(unless failover is set to manual in
repmgr.conf).