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Dirk Rudolph commented on SLING-7830: ------------------------------------- I agree on option 2 being more complex but for me this would be the favoured one. Lets say we want to run with our blue-green deployment a zero-downtime strategy where the majority of the users continue working on the green stack and a subset of samples working on the new blue stack for verification. Having the master in the blue stack could cause a service interruption for all users when an issue appears during verification. > Defined leader switch > --------------------- > > Key: SLING-7830 > URL: https://issues.apache.org/jira/browse/SLING-7830 > Project: Sling > Issue Type: Improvement > Components: Discovery > Reporter: Carsten Ziegeler > Priority: Major > > The current leader selection is based on startup time and sling id (mainly) > and is stable across changed in the topology for as long as the leader is up > and running. > However there are use cases like blue green deployment where new instances > with a new version are started and taking over the functionality. However > with the current discovery setup, the leader would still be one of the > instances with the old version. > With a new deployed version, tasks currently bound to the leader should run > on the new version. > Therefore the leader needs to switch and stay the leader (until it dies). > We probably need an additional criteria for the leader selection > /cc [~egli] -- This message was sent by Atlassian JIRA (v7.6.3#76005)