On Tue, Jan 6, 2015 at 11:01 AM, Adam Warski <a...@warski.org> wrote:
> Something like downing all members if there's no quorum? > Yes, something like that. From the "larger healthy" side of the partition mark all unreachable as down, and from the other side shutdown yourself. That will not work well for partitions that split the cluster in > 2 groups. > I was thinking about that, but there are two problems: > - under the current cluster specification, is there a way to resurrect a > node? Wouldn't "smarter downing" require you to add a new state, something > like "suspended" (waiting for enough members to be in the same state)? > Unreachable is not a member state, and it can become reachable again. However, some kind of stabilization must be awaited before the decision can be made. > - wouldn't this be too global? a per-singleton setting doesn't impact the > cluster as a whole, you can have in a single cluster some services which > require a quorum, and others which can operate even in a split brain > scenario > yes, that is a valid point > > If I get some free time I'd be happy to work on the issue, I assume master > is a good starting point? > great, master it is /Patrik > > Adam > > On Friday, January 2, 2015 3:58:37 PM UTC+1, Patrik Nordwall wrote: >> >> Hi Adam, >> >> We have been thinking that this should be handled with a "smarter" >> downing strategy, but since it would be easy to implement it in the >> singleton manager as you propose I think we should consider it. It has >> already been requested in issue: https://github.com/ >> akka/akka/issues/16535 >> >> Cheers, >> Patrik >> >> On Tue, Dec 30, 2014 at 1:07 PM, Adam Warski <ad...@warski.org> wrote: >> >>> Hello, >>> >>> I was wondering how to avoid split-brain issues when using a cluster >>> singleton and automatic downing. >>> Wouldn't it make sense to add a "min-nr-of-members" setting to the >>> singleton? That is, the singleton wouldn't start unless there's a given >>> number of members in the cluster online. That would solve the split brain >>> problem with singletons. >>> >>> I know there is the per-role "min-nr-of-members" setting, which impacts >>> the startup of the cluster as a whole, and maybe this could be re-used >>> (currently if nodes start up, and then some die (leaving a smaller number >>> than the setting alive), the singleton starts up anyway). >>> >>> Adam >>> >>> -- >>> >>>>>>>>>> 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 akka-user+...@googlegroups.com. >>> To post to this group, send email to akka...@googlegroups.com. >>> Visit this group at http://groups.google.com/group/akka-user. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> >> Patrik Nordwall >> Typesafe <http://typesafe.com/> - Reactive apps on the JVM >> Twitter: @patriknw >> >> -- > >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. > To post to this group, send email to akka-user@googlegroups.com. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > -- Patrik Nordwall Typesafe <http://typesafe.com/> - Reactive apps on the JVM Twitter: @patriknw -- >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
