Harden MultiDcClusterShardingSpec (#25201)

- Use global multi node cluster config
- Reduce retry interval for ShardRegion register
- Add clue to unhelpful assert failing

akka-cluster-sharding/src/multi-jvm/scala/akka/cluster/sharding/MultiDcClusterShardingSpec.scala

@@ -5,13 +5,11 @@
 package akka.cluster.sharding
 
 import scala.concurrent.duration._
-
 import akka.actor.Actor
 import akka.actor.ActorRef
 import akka.actor.Address
 import akka.actor.Props
-import akka.cluster.Cluster
+import akka.cluster.{ Cluster, MemberStatus, MultiNodeClusterSpec }
-import akka.cluster.MemberStatus
 import akka.cluster.sharding.ShardRegion.CurrentRegions
 import akka.cluster.sharding.ShardRegion.GetCurrentRegions
 import akka.remote.testconductor.RoleName
@@ -56,12 +54,16 @@ object MultiDcClusterShardingSpecConfig extends MultiNodeConfig {
 
   commonConfig(ConfigFactory.parseString(s"""
     akka.loglevel = DEBUG # issue #23741
-    akka.cluster.debug.verbose-heartbeat-logging = on
+    akka.cluster {
-    akka.cluster.debug.verbose-gossip-logging = on
+      debug.verbose-heartbeat-logging = on
-    akka.actor.provider = "cluster"
+      debug.verbose-gossip-logging = on
+      auto-down-unreachable-after = 0s
+      sharding {
+        retry-interval = 200ms
+      }
+    }
     akka.remote.log-remote-lifecycle-events = on
-    akka.cluster.auto-down-unreachable-after = 0s
+    """).withFallback(MultiNodeClusterSpec.clusterConfig))
-    """))
 
   nodeConfig(first, second) {
     ConfigFactory.parseString("akka.cluster.multi-data-center.self-data-center = DC1")
@@ -72,20 +74,16 @@ object MultiDcClusterShardingSpecConfig extends MultiNodeConfig {
   }
 }
 
-class MultiDcClusterShardingMultiJvmNode1 extends MultiDcClusterShardingSpec
+class MultiDcClusterShardingSpecMultiJvmNode1 extends MultiDcClusterShardingSpec
-class MultiDcClusterShardingMultiJvmNode2 extends MultiDcClusterShardingSpec
+class MultiDcClusterShardingSpecMultiJvmNode2 extends MultiDcClusterShardingSpec
-class MultiDcClusterShardingMultiJvmNode3 extends MultiDcClusterShardingSpec
+class MultiDcClusterShardingSpecMultiJvmNode3 extends MultiDcClusterShardingSpec
-class MultiDcClusterShardingMultiJvmNode4 extends MultiDcClusterShardingSpec
+class MultiDcClusterShardingSpecMultiJvmNode4 extends MultiDcClusterShardingSpec
 
-abstract class MultiDcClusterShardingSpec extends MultiNodeSpec(MultiDcClusterShardingSpecConfig)
+abstract class MultiDcClusterShardingSpec extends MultiNodeSpec(MultiDcClusterShardingSpecConfig) with MultiNodeClusterSpec
   with STMultiNodeSpec with ImplicitSender {
   import MultiDcClusterShardingSpec._
   import MultiDcClusterShardingSpecConfig._
 
-  override def initialParticipants = roles.size
-
-  val cluster = Cluster(system)
-
   def join(from: RoleName, to: RoleName): Unit = {
     runOn(from) {
       cluster join node(to).address
@@ -131,8 +129,10 @@ abstract class MultiDcClusterShardingSpec extends MultiNodeSpec(MultiDcClusterSh
       join(fourth, first)
 
       awaitAssert({
+        withClue(s"Members: ${Cluster(system).state}") {
           Cluster(system).state.members.size should ===(4)
           Cluster(system).state.members.map(_.status) should ===(Set(MemberStatus.Up))
+        }
       }, 10.seconds)
 
       runOn(first, second) {

akka-cluster/src/multi-jvm/scala/akka/cluster/MultiNodeClusterSpec.scala

@@ -95,7 +95,7 @@ object MultiNodeClusterSpec {
 
 trait MultiNodeClusterSpec extends Suite with STMultiNodeSpec with WatchedByCoroner with FlightRecordingSupport { self: MultiNodeSpec ⇒
 
-  override def initialParticipants = roles.size
+  final override def initialParticipants = roles.size
 
   private val cachedAddresses = new ConcurrentHashMap[RoleName, Address]
 
@@ -240,14 +240,14 @@ trait MultiNodeClusterSpec extends Suite with STMultiNodeSpec with WatchedByCoro
     def memberInState(member: Address, status: Seq[MemberStatus]): Boolean =
       clusterView.members.exists { m ⇒ (m.address == member) && status.contains(m.status) }
 
-    cluster join joinNode
+    cluster.join(joinNode)
     awaitCond({
       clusterView.refreshCurrentState()
       if (memberInState(joinNode, List(MemberStatus.up)) &&
         memberInState(myself, List(MemberStatus.Joining, MemberStatus.Up)))
         true
       else {
-        cluster join joinNode
+        cluster.join(joinNode)
         false
       }
     }, max, interval)