Hello Olle, Are there any way of not having all cluster-singleton actors running on the > same node ( the leader node of the cluster ) in case that a service needs > to be migrated to another node because of other reasons than a node is down > ( out of disk space or something like that ).
It does not have to be running on the cluster leader - it can run on "oldest node that has a given role", it's documented here: http://doc.akka.io/docs/akka/current/contrib/cluster-singleton.html So you can have roles like "backend" or "cpu-heavy" and then the singleton would be running on the oldest cluster member that contains each its required role. We do not support very dynamic moving of singletons around as you seem to be asking for. Singletons are usually used for light "master" or "scheduler" Actors, and the actual work would be performed by some sharded workers. Do you feel you have a strong use-case for it or are just wondering if it's possible? I noticed that you can use roles for the cluster-singleton, what happens if > a new leader is elected but without the roles needed for a particular > cluster singleton would that service be spun up on a non-leader node ? The cluster "leader" is not what decides where the singleton is being run. The singleton is running on "oldest node, that matches it's role requirements". Yes, if you do not require any roles, this requirement matches with the node that we call the cluster leader, but as you see the singleton may (and often will) run on non-leader nodes. Hope this helps! -- Konrad On Tue, Mar 31, 2015 at 8:38 AM, <[email protected]> wrote: > Hi, > > A couple of questions regarding the cluster-singleton functionality: > > - Are there any way of not having all cluster-singleton actors running > on the same node ( the leader node of the cluster ) in case that a service > needs to be migrated to another node because of other reasons than a node > is down ( out of disk space or something like that ). > - I noticed that you can use roles for the cluster-singleton, what > happens if a new leader is elected but without the roles needed for a > particular cluster singleton would that service be spun up on a non-leader > node ? > > Thanks, Olle > > > > -- > >>>>>>>>>> Read the docs: http://akka.io/docs/ > >>>>>>>>>> Check the FAQ: > http://doc.akka.io/docs/akka/current/additional/faq.html > >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user > --- > You received this message because you are subscribed to the Google Groups > "Akka User List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > -- Akka Team Typesafe - Reactive apps on the JVM Blog: letitcrash.com Twitter: @akkateam -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
