From 990ad99ca38a7088c2d7ecbbabccf2cab91f6f05 Mon Sep 17 00:00:00 2001 From: Konrad Malawski Date: Tue, 15 Apr 2014 10:22:53 +0200 Subject: [PATCH] =doc #3986 Slight updates in wording on cluster singleton docs --- akka-contrib/docs/cluster-singleton.rst | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/akka-contrib/docs/cluster-singleton.rst b/akka-contrib/docs/cluster-singleton.rst index f3c6458460..38dfa1c555 100644 --- a/akka-contrib/docs/cluster-singleton.rst +++ b/akka-contrib/docs/cluster-singleton.rst @@ -54,19 +54,19 @@ Potential problems to be aware of This pattern may seem to be very tempting to use at first, but it has several drawbacks, some of them are listed below: * the cluster singleton may quickly become a *performance bottleneck*, -* you can not rely on the cluster singleton to be *non-stop* available - e.g. when node on which the singleton was running dies, - it will take a few seconds for this to be noticed and the singleton be migrated to another node, -* in the case of a network partition appearing in a Cluster that is using Automatic Downing (:ref:`automatic-vs-manual-downing-scala`), +* you can not rely on the cluster singleton to be *non-stop* available — e.g. when the node on which the singleton has + been running dies, it will take a few seconds for this to be noticed and the singleton be migrated to another node, +* in the case of a *network partition* appearing in a Cluster that is using Automatic Downing (see Auto Downing docs for :ref:`Scala ` or :ref:`Java `), it may happen that the isolated clusters each decide to spin up their own singleton, meaning that there might be multiple - singletons running in the system, yet the Clusters have no way of finding out about them (because of the network partition). + singletons running in the system, yet the Clusters have no way of finding out about them (because of the partition). -Especially the last point is something you should be aware of - in general when using the Cluster Singleton pattern +Especially the last point is something you should be aware of — in general when using the Cluster Singleton pattern you should take care of downing nodes yourself and not rely on the timing based auto-down feature. .. warning:: **Be very careful when using Cluster Singleton together with Automatic Downing**, since it allows the cluster to split up into two separate clusters, which in turn will result - in *multiple Singletons* being started - one in each separate cluster! + in *multiple Singletons* being started, one in each separate cluster! An Example ----------