ClusterStressSpec and Cluster Failure Detector Cleanup (#4940)

* implementation of Akka.Cluster.Tests.MultiNode.StressSpec

* made MuteLog overrideable in Akka.Cluster.Testkit

* if Roles is empty, then don't run the thunk on any nodes

Changed this to make it consistent with the JVM

* made it possible to actually enable Cluster.AssertInvariants via environment variable

* added assert invariants to build script

cleaned up gossip class to assert more invariants

* ReSharper'd Reachability.cs

* cleaned up immutability and CAS issues inside DefaultFailureDetectorRegistry

added bugfix from akka/akka#23595

build.fsx

@@ -348,6 +348,7 @@ Target "MultiNodeTests" (fun _ ->
 
 Target "MultiNodeTestsNetCore" (fun _ ->
     if not skipBuild.Value then
+        setEnvironVar "akka.cluster.assert" "on" // needed to enable assert invariants for Akka.Cluster
         let multiNodeTestPath = findToolInSubPath "Akka.MultiNodeTestRunner.dll" (currentDirectory @@ "src" @@ "core" @@ "Akka.MultiNodeTestRunner" @@ "bin" @@ "Release" @@ testNetCoreVersion @@ "win10-x64" @@ "publish")
 
         let projects =
@@ -388,6 +389,7 @@ Target "MultiNodeTestsNetCore" (fun _ ->
 )
 Target "MultiNodeTestsNet" (fun _ ->
     if not skipBuild.Value then
+        setEnvironVar "akka.cluster.assert" "on" // needed to enable assert invariants for Akka.Cluster
         let multiNodeTestPath = findToolInSubPath "Akka.MultiNodeTestRunner.dll" (currentDirectory @@ "src" @@ "core" @@ "Akka.MultiNodeTestRunner" @@ "bin" @@ "Release" @@ testNetVersion @@ "win10-x64" @@ "publish")
 
         let projects =

src/common.props

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <Copyright>Copyright © 2013-2021 Akka.NET Team</Copyright>
     <Authors>Akka.NET Team</Authors>
-    <VersionPrefix>1.4.18</VersionPrefix>
+    <VersionPrefix>1.4.19</VersionPrefix>
     <PackageIconUrl>https://getakka.net/images/akkalogo.png</PackageIconUrl>
     <PackageProjectUrl>https://github.com/akkadotnet/akka.net</PackageProjectUrl>
     <PackageLicenseUrl>https://github.com/akkadotnet/akka.net/blob/master/LICENSE</PackageLicenseUrl>
@@ -29,7 +29,7 @@
     <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
   </PropertyGroup>
   <PropertyGroup>
-    <PackageReleaseNotes>Placeholder for Nightlies**</PackageReleaseNotes>
+    <PackageReleaseNotes>Placeholder for nightlies**</PackageReleaseNotes>
   </PropertyGroup>
   <!-- SourceLink support for all Akka.NET projects -->
   <ItemGroup>

src/core/Akka.Cluster.TestKit/MultiNodeClusterSpec.cs

@@ -175,7 +175,7 @@ protected override void AfterTermination()
 
         //TODO: ExpectedTestDuration?
 
-        void MuteLog(ActorSystem sys = null)
+        public virtual void MuteLog(ActorSystem sys = null)
         {
             if (sys == null) sys = Sys;
             if (!sys.Log.IsDebugEnabled)

src/core/Akka.Cluster.Tests.MultiNode/Akka.Cluster.Tests.MultiNode.csproj

@@ -4,6 +4,7 @@
   <PropertyGroup>
     <AssemblyTitle>Akka.Cluster.Tests.MultiNode</AssemblyTitle>
     <TargetFrameworks>$(NetFrameworkTestVersion);$(NetTestVersion);$(NetCoreTestVersion)</TargetFrameworks>
+    <LangVersion>latest</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/core/Akka.Cluster.Tests.MultiNode/Bugfix4353Specs.cs

@@ -36,7 +36,7 @@ protected Bugfix4353Spec(Bugfix4353SpecsConfig config) : base(config, typeof(Bug
         }
 
         [MultiNodeFact]
-        public void Bugfix4353Spec_Cluster_of_3_must_reach_cnovergence()
+        public void Bugfix4353Spec_Cluster_of_3_must_reach_convergence()
         {
             AwaitClusterUp(First, Second, Third);
             EnterBarrier("after-1");