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Diffstat (limited to 'doc/source/user/tutorial/leader_election.rst')
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diff --git a/doc/source/user/tutorial/leader_election.rst b/doc/source/user/tutorial/leader_election.rst new file mode 100644 index 0000000..df2a77b --- /dev/null +++ b/doc/source/user/tutorial/leader_election.rst @@ -0,0 +1,25 @@ +================= + Leader Election +================= + +Each group can elect its own leader. There can be only one leader at a time +in a group. Only members that are running for the election can be elected. +As soon as one of leader steps down or dies, a new member that was running +for the election will be elected. + +.. literalinclude:: ../../../../examples/leader_election.py + :language: python + +The method +:meth:`tooz.coordination.CoordinationDriver.watch_elected_as_leader` allows +to register for a function to be called back when the member is elected as a +leader. Using this function indicates that the run is therefore running for +the election. The member can stop running by unregistering all its callbacks +with :meth:`tooz.coordination.CoordinationDriver.unwatch_elected_as_leader`. +It can also temporarily try to step down as a leader with +:meth:`tooz.coordination.CoordinationDriver.stand_down_group_leader`. If +another member is in the run for election, it may be elected instead. + +To retrieve the leader of a group, even when not being part of the group, +the method :meth:`tooz.coordination.CoordinationDriver.get_leader()` can be +used. |