> On 09 Sep 2015, at 04:48, Emmanuel <ele...@msn.com> wrote: > > my questions is: how critical is the bootstrap ip list in masters?
Hey Emmanuel, good questions. I read over the docs for this again [1] and you are right that we should make this clearer. The “masters" file is only relevant for the start/stop cluster scripts (Flink standalone mode). If you specify hosts in the “masters" file the start-cluster scripts will use these hosts to start job managers. After that all coordination happens via ZooKeeper via a leader election and retrieval service. All job managers elect a single leader and task managers and clients (submitting programs) retrieve this leader via ZooKeeper. If a job manager fails and becomes available again, it will publish itself via this mechanism (if it becomes leader at some point again). There was a recent PR [2] which introduced this. You can read over the very good PR description for more info for now. [1] https://ci.apache.org/projects/flink/flink-docs-master/setup/jobmanager_high_availability.html [2] https://github.com/apache/flink/pull/1016 > does this get updated or does it have to be updated by some other service? If you start a new cluster on GCE with different hosts and use Flink’s standalone mode you have to set this up again. This is the same for the “slaves” file. Does this answer your question? If anything is unclear, please post here. :) – Ufuk
