Is there a quorum for keepalived?

Question

linux

You need to implement a mechanism to avoid the split-brain state.
In the simplest situation, the work of keepalived is clear, but how to avoid a situation in which two nodes become masters, as an example, you can take a service that accesses the database (mysql master-master). At one point in time, the service that accesses the database is running on only one node, what if a split-brain situation occurs. Both keepalived nodes recognize themselves as masters. What control mechanism to use to avoid this, ideally I would like a third-party quorum, but I did not find information about this in the docks.

Answer 1

keepalived is not the right tool for this because it aims to ensure that the resource is available in at least one location, while heartbeat, for example, seeks to ensure that the resource is available in at most one location.
The haproxy developer answered this question in sufficient detail: www.formilux.org/archives/haproxy/1003/3259.html

Answer 2

keepalived has a built-in quorum mechanism. An example configuration can be found here: https://github.com/acassen/keepalived/blob/master/... Keep
in mind that the quorum mechanism does not make any sense if there are only 2 nodes available. There must be 3 or more.