This implementation is using the same interface (AbstractDCS) as Etcd
class. It means that there should be no problem to implement another
plugin to work agains Consul for example.
In case if it was interrupted by SIGCHLD but scheduled awake time is not
reached it will continue sleeping. For all other signals behaviuor is
not changed.
In order to have backward compatibility connection url of restapi is
passed as application_name parameter in connection url of database.
Value in etcd will look like:
postgres://user:passwd@host:5432/postgres?application_name=http://host:8080/governor
Sure, this is a hack, but I guess it worth it.
Server always returns json which contains some status of postgres:
* instance type: master/slave
* xlog location for master
* xlog received_location, replayed_location
This server could be used by haproxy
GET / returns 200 if there is postgres master behind governor.
GET /slave returns 200 is there is postgres slave behind governor
In all other cases it returns 503
Currently server always listening on 0.0.0.0:8080, but it should be
configurable. In the next versions this rest api could also report some
status of etcd and could be used by is_healthiest_node method
Also governor is able to pick up already running master and slave
instances without restarting them.
In case is you have a lock and postgres is not running behaviour remains
the same: it will start master in read only mode and then promote if it
still has the lock.
Alexander Kukushkin