diff --git a/src/OrleansTestingHost/TestingSiloHost.cs b/src/OrleansTestingHost/TestingSiloHost.cs
index c01033ad68..69dac435c0 100644
--- a/src/OrleansTestingHost/TestingSiloHost.cs
+++ b/src/OrleansTestingHost/TestingSiloHost.cs
@@ -35,6 +35,7 @@ namespace Orleans.TestingHost
     /// Also make sure that your test project references your test grains and test grain interfaces 
     /// projects, and has CopyLocal=True set on those references [which should be the default].
     /// </remarks>
+    [Obsolete("Use TestCluster", false)]
     public class TestingSiloHost
     {
         /// <summary> Single instance of TestingSiloHost </summary>
diff --git a/test/Tester/CollectionFixtures.cs b/test/Tester/CollectionFixtures.cs
index d683568524..de7c59be55 100644
--- a/test/Tester/CollectionFixtures.cs
+++ b/test/Tester/CollectionFixtures.cs
@@ -9,4 +9,13 @@ public class DefaultClusterTestCollection : ICollectionFixture<DefaultClusterFix
 
     [CollectionDefinition(TestEnvironmentFixture.DefaultCollection)]
     public class TestEnvironmentFixtureCollection : ICollectionFixture<TestEnvironmentFixture> { }
+
+    public abstract class BaseAzureTestClusterFixture : BaseTestClusterFixture
+    {
+        protected override void CheckPreconditionsOrThrow()
+        {
+            base.CheckPreconditionsOrThrow();
+            TestUtils.CheckForAzureStorage();
+        }
+    }
 }
diff --git a/test/TesterAzureUtils/CollectionFixtures.cs b/test/TesterAzureUtils/CollectionFixtures.cs
index 189f783db7..0b49cf5d0b 100644
--- a/test/TesterAzureUtils/CollectionFixtures.cs
+++ b/test/TesterAzureUtils/CollectionFixtures.cs
@@ -9,13 +9,4 @@ public class DefaultClusterTestCollection : ICollectionFixture<DefaultClusterFix
     
     [CollectionDefinition(TestEnvironmentFixture.DefaultCollection)]
     public class TestEnvironmentFixtureCollection : ICollectionFixture<TestEnvironmentFixture> { }
-
-    public abstract class BaseAzureTestClusterFixture : BaseTestClusterFixture
-    {
-        protected override void CheckPreconditionsOrThrow()
-        {
-            base.CheckPreconditionsOrThrow();
-            TestUtils.CheckForAzureStorage();
-        }
-    }
 }
diff --git a/test/TesterInternal/GeoClusterTests/BasicLogTestGrainTests.cs b/test/TesterInternal/GeoClusterTests/BasicLogTestGrainTests.cs
index 72bb4be26d..e625681e36 100644
--- a/test/TesterInternal/GeoClusterTests/BasicLogTestGrainTests.cs
+++ b/test/TesterInternal/GeoClusterTests/BasicLogTestGrainTests.cs
@@ -8,17 +8,18 @@
 using UnitTests.GrainInterfaces;
 using Orleans.TestingHost;
 using Xunit;
-using Assert = Xunit.Assert;
 using TestExtensions;
+using Tester;
 
 namespace Tests.GeoClusterTests
 {
+    [TestCategory("GeoCluster")]
     public class BasicLogTestGrainTests : IClassFixture<BasicLogTestGrainTests.Fixture>
     {
         private readonly Fixture fixture;
         private Random random;
 
-        public class Fixture : BaseTestClusterFixture
+        public class Fixture : BaseAzureTestClusterFixture
         {
             protected override TestCluster CreateTestCluster()
             {
@@ -43,35 +44,36 @@ protected override TestCluster CreateTestCluster()
         public BasicLogTestGrainTests(Fixture fixture)
         {
             this.fixture = fixture;
+            fixture.EnsurePreconditionsMet();
             this.random = new Random();
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task DefaultStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.LogTestGrainDefaultStorage");
         }
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task MemoryStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.LogTestGrainMemoryStorage");
         }
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task SharedStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.LogTestGrainSharedStateStorage");
         }
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task SharedLogStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.LogTestGrainSharedLogStorage");
         }
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task CustomStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.LogTestGrainCustomStorage");
         }
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task GsiStorage()
         {
             await DoBasicLogTestGrainTest("TestGrains.GsiLogTestGrain");
diff --git a/test/TesterInternal/GeoClusterTests/GlobalSingleInstanceClusterTests.cs b/test/TesterInternal/GeoClusterTests/GlobalSingleInstanceClusterTests.cs
index dc3ba29d46..49c2151725 100644
--- a/test/TesterInternal/GeoClusterTests/GlobalSingleInstanceClusterTests.cs
+++ b/test/TesterInternal/GeoClusterTests/GlobalSingleInstanceClusterTests.cs
@@ -109,8 +109,8 @@ await RunWithTimeout("Setup_Clusters", largesetup ? 120000 : 60000, async () =>
                 // Create two clusters, each with a single silo.
                 cluster0 = "cluster0";
                 cluster1 = "cluster1";
-                NewGeoCluster(globalserviceid, cluster0, largesetup ? 3 : 1, configurationcustomizer);
-                NewGeoCluster(globalserviceid, cluster1, largesetup ? 4 : 1, configurationcustomizer);
+                NewGeoCluster(globalserviceid, cluster0, (short)(largesetup ? 3 : 1), configurationcustomizer);
+                NewGeoCluster(globalserviceid, cluster1, (short)(largesetup ? 4 : 1), configurationcustomizer);
 
                 if (!largesetup)
                 {
@@ -508,7 +508,7 @@ public async Task ConflictResolution()
         private List<GrainId> GetGrainsInClusterWithStatus(string clusterId, GrainDirectoryEntryStatus? status = null)
         {
             List<GrainId> grains = new List<GrainId>();
-            var silos = Clusters[clusterId].Silos;
+            var silos = Clusters[clusterId].Cluster.GetActiveSilos();
             int totalSoFar = 0;
             foreach (var silo in silos)
             {
diff --git a/test/TesterInternal/GeoClusterTests/LogConsistencyTestFixture.cs b/test/TesterInternal/GeoClusterTests/LogConsistencyTestFixture.cs
index 0008f34a9d..056d32d35e 100644
--- a/test/TesterInternal/GeoClusterTests/LogConsistencyTestFixture.cs
+++ b/test/TesterInternal/GeoClusterTests/LogConsistencyTestFixture.cs
@@ -6,13 +6,12 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
-using UnitTests.GrainInterfaces;
 using Xunit;
 using Xunit.Abstractions;
 using TestExtensions;
 using Orleans.EventSourcing.Common;
+using Tester;
 
 namespace Tests.GeoClusterTests
 {
@@ -21,8 +20,19 @@ namespace Tests.GeoClusterTests
     ///  (concurrent reading and updating, update propagation, conflict resolution)
     ///  on a multicluster with the desired number of clusters
     /// </summary>
-    public class LogConsistencyTestFixture : TestingClusterHost
+    public class LogConsistencyTestFixture : IDisposable
     {
+        TestingClusterHost _hostedMultiCluster;
+
+        public TestingClusterHost MultiCluster
+        {
+            get { return _hostedMultiCluster ?? (_hostedMultiCluster = new TestingClusterHost()); }
+        }
+
+        public void EnsurePreconditionsMet()
+        {
+            TestUtils.CheckForAzureStorage();
+        }
 
         #region client wrappers
 
@@ -133,15 +143,13 @@ public IEnumerable<ConnectionIssue> GetUnresolvedConnectionIssues(string graincl
 
         public void StartClustersIfNeeded(int numclusters, ITestOutputHelper output)
         {
-            this.output = output;
-
-            if (Clusters.Count != numclusters)
+            if (MultiCluster.Clusters.Count != numclusters)
             {
-                if (Clusters.Count > 0)
-                    StopAllClientsAndClusters();
+                if (MultiCluster.Clusters.Count > 0)
+                    MultiCluster.StopAllClientsAndClusters();
 
 
-                WriteLog("Creating {0} clusters and clients...", numclusters);
+                output.WriteLine("Creating {0} clusters and clients...", numclusters);
                 this.numclusters = numclusters;
 
                 Assert.True(numclusters >= 2);
@@ -161,32 +169,31 @@ public void StartClustersIfNeeded(int numclusters, ITestOutputHelper output)
                 for (int i = 0; i < numclusters; i++)
                 {
                     var clustername = Cluster[i] = ((char)('A' + i)).ToString();
-                    NewGeoCluster(globalserviceid, clustername, 1,
+                    MultiCluster.NewGeoCluster(globalserviceid, clustername, 1,
                         cfg => LogConsistencyProviderConfiguration.ConfigureLogConsistencyProvidersForTesting(TestDefaultConfiguration.DataConnectionString, cfg));
-                    Client[i] = this.NewClient(clustername, 0, ClientWrapper.Factory);
+                    Client[i] = this.MultiCluster.NewClient(clustername, 0, ClientWrapper.Factory);
                 }
 
-                WriteLog("Clusters and clients are ready (elapsed = {0})", stopwatch.Elapsed);
+                output.WriteLine("Clusters and clients are ready (elapsed = {0})", stopwatch.Elapsed);
 
                 // wait for configuration to stabilize
-                WaitForLivenessToStabilizeAsync().WaitWithThrow(TimeSpan.FromMinutes(1));
+                MultiCluster.WaitForLivenessToStabilizeAsync().WaitWithThrow(TimeSpan.FromMinutes(1));
 
                 Client[0].InjectClusterConfiguration(Cluster);
-                WaitForMultiClusterGossipToStabilizeAsync(false).WaitWithThrow(TimeSpan.FromMinutes(System.Diagnostics.Debugger.IsAttached ? 60 : 1));
+                MultiCluster.WaitForMultiClusterGossipToStabilizeAsync(false).WaitWithThrow(TimeSpan.FromMinutes(System.Diagnostics.Debugger.IsAttached ? 60 : 1));
 
                 stopwatch.Stop();
-                WriteLog("Multicluster is ready (elapsed = {0}).", stopwatch.Elapsed);
+                output.WriteLine("Multicluster is ready (elapsed = {0}).", stopwatch.Elapsed);
             }
             else
             {
-                WriteLog("Reusing existing {0} clusters and clients.", numclusters);
+                output.WriteLine("Reusing existing {0} clusters and clients.", numclusters);
             }
         }
 
-        public override void Dispose()
+        public virtual void Dispose()
         {
-            base.output = null; // cannot trace during dispose from fixtures
-            base.Dispose();
+            _hostedMultiCluster?.Dispose();
         }
 
         protected ClientWrapper[] Client;
@@ -196,15 +203,10 @@ public override void Dispose()
 
         private const int Xyz = 333;
 
-        public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_all_clusters, int phases)
+        public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_all_clusters, int phases, ITestOutputHelper output)
         {
-            Random random = new Random();
-
-            Func<int> GetRandom = () =>
-            {
-                lock (random)
-                    return random.Next();
-            };
+            var random = new SafeRandom();
+            Func<int> GetRandom = () => random.Next();
 
             Func<Task> checker1 = () => Task.Run(() =>
             {
@@ -212,21 +214,21 @@ public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_al
                 var grainidentity = string.Format("grainref={0}", Client[0].GetGrainRef(grainClass, x));
                 // force creation of replicas
                 for (int i = 0; i < numclusters; i++) 
-                   AssertEqual(0, Client[i].GetALocal(grainClass, x), grainidentity); 
+                   Assert.Equal(0, Client[i].GetALocal(grainClass, x)); 
                 // write global on client 0
                 Client[0].SetAGlobal(grainClass, x, Xyz);
                 // read global on other clients
                 for (int i = 1; i < numclusters; i++)
                 {
                     int r = Client[i].GetAGlobal(grainClass, x);
-                    AssertEqual(Xyz, r, grainidentity);
+                    Assert.Equal(Xyz, r);
                 }
                 // check local stability
                 for (int i = 0; i < numclusters; i++)
-                    AssertEqual(Xyz, Client[i].GetALocal(grainClass, x), grainidentity);
+                    Assert.Equal(Xyz, Client[i].GetALocal(grainClass, x));
                 // check versions
                 for (int i = 0; i < numclusters; i++)
-                    AssertEqual(1, Client[i].GetConfirmedVersion(grainClass, x), grainidentity);
+                    Assert.Equal(1, Client[i].GetConfirmedVersion(grainClass, x));
             });
 
             Func<Task> checker2 = () => Task.Run(() =>
@@ -239,11 +241,11 @@ public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_al
                 for (int i = 1; i < numclusters; i++)
                 {
                     int r = Client[i].GetAGlobal(grainClass, x);
-                    AssertEqual(1, r, grainidentity);
+                    Assert.Equal(1, r);
                 }
                 // check versions
                 for (int i = 0; i < numclusters; i++)
-                    AssertEqual(1, Client[i].GetConfirmedVersion(grainClass, x), grainidentity);
+                    Assert.Equal(1, Client[i].GetConfirmedVersion(grainClass, x));
             });
 
             Func<Task> checker2b = () => Task.Run(() =>
@@ -251,18 +253,18 @@ public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_al
                 int x = GetRandom();
                 var grainidentity = string.Format("grainref={0}", Client[0].GetGrainRef(grainClass, x));
                 // force first creation on replica 1
-                AssertEqual(0, Client[1].GetAGlobal(grainClass, x), grainidentity);
+                Assert.Equal(0, Client[1].GetAGlobal(grainClass, x));
                 // increment on replica 0
                 Client[0].IncrementAGlobal(grainClass, x);
                 // expect on other replicas
                 for (int i = 1; i < numclusters; i++)
                 {
                     int r = Client[i].GetAGlobal(grainClass, x);
-                    AssertEqual(1, r, grainidentity);
+                    Assert.Equal(1, r);
                 }
                 // check versions
                 for (int i = 0; i < numclusters; i++)
-                    AssertEqual(1, Client[i].GetConfirmedVersion(grainClass, x), grainidentity);
+                    Assert.Equal(1, Client[i].GetConfirmedVersion(grainClass, x));
             });
 
             Func<int, Task> checker3 = (int numupdates) => Task.Run(() =>
@@ -284,14 +286,14 @@ public async Task RunChecksOnGrainClass(string grainClass, bool may_update_in_al
                 }
 
                 // push & get all
-                AssertEqual(numupdates, Client[0].GetAGlobal(grainClass, x), grainidentity); 
+                Assert.Equal(numupdates, Client[0].GetAGlobal(grainClass, x)); 
 
                 for (int i = 1; i < numclusters; i++)
-                    AssertEqual(numupdates, Client[i].GetAGlobal(grainClass, x), grainidentity); // get all
+                    Assert.Equal(numupdates, Client[i].GetAGlobal(grainClass, x)); // get all
 
                 // check versions
                 for (int i = 0; i < numclusters; i++)
-                    AssertEqual(numupdates, Client[i].GetConfirmedVersion(grainClass, x), grainidentity);
+                    Assert.Equal(numupdates, Client[i].GetConfirmedVersion(grainClass, x));
             });
 
             Func<Task> checker4 = () => Task.Run(() =>
@@ -367,7 +369,7 @@ await Task.WhenAny(
                     Task.WhenAll(t)
                 );
 
-                AssertEqual(true, done.All(b => b), string.Format("checker6({0}): update did not propagate within 20 sec", preload));
+                Assert.True(done.All(b => b), string.Format("checker6({0}): update did not propagate within 20 sec", preload));
             };
 
             Func<int, Task> checker7 = (int variation) => Task.Run(async () =>
@@ -384,9 +386,9 @@ await Task.WhenAny(
                 // write conditional on client 0, should always succeed
                 {
                     var result = Client[0].SetAConditional(grainClass, x, Xyz);
-                    AssertEqual(0, result.Item1, grainidentity);
-                    AssertEqual(true, result.Item2, grainidentity);
-                    AssertEqual(1, Client[0].GetConfirmedVersion(grainClass, x), grainidentity);
+                    Assert.Equal(0, result.Item1);
+                    Assert.Equal(true, result.Item2);
+                    Assert.Equal(1, Client[0].GetConfirmedVersion(grainClass, x));
                 }
 
                 if ((variation / 4) % 2 == 1)
@@ -397,30 +399,30 @@ await Task.WhenAny(
                     var result = Client[1].SetAConditional(grainClass, x, 444);
                     if (result.Item1 == 0) // was stale, thus failed
                     {
-                        AssertEqual(false, result.Item2, grainidentity);
+                        Assert.Equal(false, result.Item2);
                         // must have updated as a result
-                        AssertEqual(1, Client[1].GetConfirmedVersion(grainClass, x), grainidentity);
+                        Assert.Equal(1, Client[1].GetConfirmedVersion(grainClass, x));
                         // check stability
-                        AssertEqual(Xyz, Client[0].GetALocal(grainClass, x), grainidentity);
-                        AssertEqual(Xyz, Client[1].GetALocal(grainClass, x), grainidentity);
-                        AssertEqual(Xyz, Client[0].GetAGlobal(grainClass, x), grainidentity);
-                        AssertEqual(Xyz, Client[1].GetAGlobal(grainClass, x), grainidentity);
+                        Assert.Equal(Xyz, Client[0].GetALocal(grainClass, x));
+                        Assert.Equal(Xyz, Client[1].GetALocal(grainClass, x));
+                        Assert.Equal(Xyz, Client[0].GetAGlobal(grainClass, x));
+                        Assert.Equal(Xyz, Client[1].GetAGlobal(grainClass, x));
                     }
                     else // was up-to-date, thus succeeded
                     {
-                        AssertEqual(true, result.Item2, grainidentity);
-                        AssertEqual(1, result.Item1, grainidentity);
+                        Assert.Equal(true, result.Item2);
+                        Assert.Equal(1, result.Item1);
                         // version is now 2
-                        AssertEqual(2, Client[1].GetConfirmedVersion(grainClass, x), grainidentity);
+                        Assert.Equal(2, Client[1].GetConfirmedVersion(grainClass, x));
                         // check stability
-                        AssertEqual(444, Client[1].GetALocal(grainClass, x), grainidentity);
-                        AssertEqual(444, Client[0].GetAGlobal(grainClass, x), grainidentity);
-                        AssertEqual(444, Client[1].GetAGlobal(grainClass, x), grainidentity);
+                        Assert.Equal(444, Client[1].GetALocal(grainClass, x));
+                        Assert.Equal(444, Client[0].GetAGlobal(grainClass, x));
+                        Assert.Equal(444, Client[1].GetAGlobal(grainClass, x));
                     }
                 }
             });
 
-            WriteLog("Running individual short tests");
+            output.WriteLine("Running individual short tests");
 
             // first, run short ones in sequence
             await checker1();
@@ -445,15 +447,15 @@ await Task.WhenAny(
                 await checker7(7);
 
                 // run tests under blocked notification to force race one way
-                SetProtocolMessageFilterForTesting(Cluster[0], msg => ! (msg is INotificationMessage));
+                MultiCluster.SetProtocolMessageFilterForTesting(Cluster[0], msg => ! (msg is INotificationMessage));
                 await checker7(0);
                 await checker7(1);
                 await checker7(2);
                 await checker7(3);
-                SetProtocolMessageFilterForTesting(Cluster[0], _ => true);
+                MultiCluster.SetProtocolMessageFilterForTesting(Cluster[0], _ => true);
             }
 
-            WriteLog("Running individual longer tests");
+            output.WriteLine("Running individual longer tests");
 
             // then, run slightly longer tests
             if (phases != 0)
@@ -462,7 +464,7 @@ await Task.WhenAny(
                 await checker3(phases);
             }
 
-            WriteLog("Running many concurrent test instances");
+            output.WriteLine("Running many concurrent test instances");
 
             var tasks = new List<Task>();
             for (int i = 0; i < phases; i++)
diff --git a/test/TesterInternal/GeoClusterTests/LogConsistencyTestsFourClusters.cs b/test/TesterInternal/GeoClusterTests/LogConsistencyTestsFourClusters.cs
index 58258cb64d..9e1f2d4532 100644
--- a/test/TesterInternal/GeoClusterTests/LogConsistencyTestsFourClusters.cs
+++ b/test/TesterInternal/GeoClusterTests/LogConsistencyTestsFourClusters.cs
@@ -1,70 +1,62 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Orleans;
-using Orleans.TestingHost;
-using UnitTests.GrainInterfaces;
-using Orleans.Runtime;
-using Tests.GeoClusterTests;
+using System.Threading.Tasks;
 using Xunit;
 using Xunit.Abstractions;
-using Orleans.Runtime.Configuration;
-using Tester;
 
 namespace Tests.GeoClusterTests
 {
-    public class LogConsistencyTestsFourClusters :
-       IClassFixture<LogConsistencyTestsFourClusters.Fixture>
+    [TestCategory("GeoCluster")]
+    public class LogConsistencyTestsFourClusters : IClassFixture<LogConsistencyTestsFourClusters.Fixture>
     {
+        const int phases = 100;
+        private ITestOutputHelper output;
+        private Fixture fixture;
 
         public LogConsistencyTestsFourClusters(ITestOutputHelper output, Fixture fixture)
         {
+            fixture.EnsurePreconditionsMet();
             this.fixture = fixture;
+            this.output = output;
             fixture.StartClustersIfNeeded(4, output);
         }
-        Fixture fixture;
 
         public class Fixture : LogConsistencyTestFixture
         {
         }
 
-        const int phases = 100;
-
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_SharedStateStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedStateStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedStateStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_SharedLogStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedLogStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedLogStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_GsiDefaultStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.GsiLogTestGrain", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.GsiLogTestGrain", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_MemoryStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainMemoryStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainMemoryStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_CustomStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_CustomStorageProvider_PrimaryCluster()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStoragePrimaryCluster", false, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStoragePrimaryCluster", false, phases, output);
         }
-
     }
 }
diff --git a/test/TesterInternal/GeoClusterTests/LogConsistencyTestsTwoClusters.cs b/test/TesterInternal/GeoClusterTests/LogConsistencyTestsTwoClusters.cs
index f9cae2d840..47c312cb9f 100644
--- a/test/TesterInternal/GeoClusterTests/LogConsistencyTestsTwoClusters.cs
+++ b/test/TesterInternal/GeoClusterTests/LogConsistencyTestsTwoClusters.cs
@@ -1,70 +1,62 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Orleans;
-using Orleans.TestingHost;
-using UnitTests.GrainInterfaces;
-using Orleans.Runtime;
-using Tests.GeoClusterTests;
+using System.Threading.Tasks;
 using Xunit;
 using Xunit.Abstractions;
-using Orleans.Runtime.Configuration;
 
 namespace Tests.GeoClusterTests
 {
-    public class LogConsistencyTestsTwoClusters: 
-        IClassFixture<LogConsistencyTestsTwoClusters.Fixture>
+    [TestCategory("GeoCluster")]
+    public class LogConsistencyTestsTwoClusters: IClassFixture<LogConsistencyTestsTwoClusters.Fixture>
     {
+        const int phases = 100;
+        private ITestOutputHelper output;
+        private Fixture fixture;
 
         public LogConsistencyTestsTwoClusters(ITestOutputHelper output, Fixture fixture) 
         {
+            fixture.EnsurePreconditionsMet();
             this.fixture = fixture;
+            this.output = output;
             fixture.StartClustersIfNeeded(2, output);
         }
-        Fixture fixture;
 
         public class Fixture : LogConsistencyTestFixture
         {
         }
 
-        const int phases = 100;
-
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_SharedStateStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedStateStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedStateStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_SharedLogStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedLogStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainSharedLogStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_GsiDefaultStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.GsiLogTestGrain", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.GsiLogTestGrain", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_MemoryStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainMemoryStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainMemoryStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_CustomStorageProvider()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStorage", true, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStorage", true, phases, output);
         }
 
-        [Fact, TestCategory("GeoCluster")]
+        [SkippableFact]
         public async Task TestBattery_CustomStorageProvider_PrimaryCluster()
         {
-            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStoragePrimaryCluster", false, phases);
+            await fixture.RunChecksOnGrainClass("TestGrains.LogTestGrainCustomStoragePrimaryCluster", false, phases, output);
         }
-
-
     }
 }
diff --git a/test/TesterInternal/GeoClusterTests/MultiClusterNetworkTests.cs b/test/TesterInternal/GeoClusterTests/MultiClusterNetworkTests.cs
index 8ac5139d23..c26e6a9f31 100644
--- a/test/TesterInternal/GeoClusterTests/MultiClusterNetworkTests.cs
+++ b/test/TesterInternal/GeoClusterTests/MultiClusterNetworkTests.cs
@@ -64,7 +64,7 @@ public async Task TestMultiClusterConf_1_1()
             // create cluster A and clientA
             var clusterA = "A";
             NewGeoCluster(globalserviceid, clusterA, 1);
-            var siloA = Clusters[clusterA].Silos[0].SiloAddress.Endpoint;
+            var siloA = Clusters[clusterA].Silos.First().SiloAddress.Endpoint;
             var clientA = this.NewClient<ClientWrapper>(clusterA, 0, ClientWrapper.Factory);
 
             var cur = clientA.GetMultiClusterConfiguration();
@@ -84,7 +84,7 @@ public async Task TestMultiClusterConf_1_1()
             // create cluster B and clientB
             var clusterB = "B";
             NewGeoCluster(globalserviceid, clusterB, 1);
-            var siloB = Clusters[clusterB].Silos[0].SiloAddress.Endpoint;
+            var siloB = Clusters[clusterB].Silos.First().SiloAddress.Endpoint;
             var clientB = NewClient<ClientWrapper>(clusterB, 0, ClientWrapper.Factory);
 
             cur = clientB.GetMultiClusterConfiguration();
@@ -121,7 +121,7 @@ public async Task TestMultiClusterConf_1_1()
             }
 
             // shut down cluster B
-            StopSilo(Clusters[clusterB].Silos[0]);
+            Clusters[clusterB].Cluster.StopAllSilos();
             await WaitForLivenessToStabilizeAsync();
 
             // expect disappearance of gateway from multicluster network
@@ -170,16 +170,12 @@ public async Task TestMultiClusterConf_3_3()
             // create cluster A and clientA
             NewGeoCluster(globalserviceid, clusterA, 3, configcustomizer);
             var clientA = this.NewClient<ClientWrapper>(clusterA, 0, ClientWrapper.Factory);
-            var portA0 = Clusters[clusterA].Silos[0].SiloAddress.Endpoint.Port;
-            var portA1 = Clusters[clusterA].Silos[1].SiloAddress.Endpoint.Port;
-            var portA2 = Clusters[clusterA].Silos[2].SiloAddress.Endpoint.Port;
+            var portsA = Clusters[clusterA].Cluster.GetActiveSilos().Select(x => x.SiloAddress.Endpoint.Port).ToArray();
 
             // create cluster B and clientB
             NewGeoCluster(globalserviceid, clusterB, 3, configcustomizer);
             var clientB = this.NewClient<ClientWrapper>(clusterB, 0, ClientWrapper.Factory);
-            var portB0 = Clusters[clusterB].Silos[0].SiloAddress.Endpoint.Port;
-            var portB1 = Clusters[clusterB].Silos[1].SiloAddress.Endpoint.Port;
-            var portB2 = Clusters[clusterB].Silos[2].SiloAddress.Endpoint.Port;
+            var portsB = Clusters[clusterB].Cluster.GetActiveSilos().Select(x => x.SiloAddress.Endpoint.Port).ToArray();
 
             // wait for membership to stabilize
             await WaitForLivenessToStabilizeAsync();
@@ -193,32 +189,32 @@ public async Task TestMultiClusterConf_3_3()
 
             // expect 4 active gateways, two per cluster
             var activegateways = clientA.GetMultiClusterGateways().Where(g => g.Status == GatewayStatus.Active).ToList();
-            Assert.Equal(string.Join(",", portA0, portA1),
+            Assert.Equal(string.Join(",", portsA[0], portsA[1]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterA).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
-            Assert.Equal(string.Join(",", portB0, portB1),
+            Assert.Equal(string.Join(",", portsB[0], portsB[1]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterB).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
             var activegatewaysB = clientB.GetMultiClusterGateways().Where(g => g.Status == GatewayStatus.Active).ToList();
  
             // shut down one of the gateways in cluster B gracefully
-            var target = Clusters[clusterB].Silos.Where(h => h.SiloAddress.Endpoint.Port == portB1).FirstOrDefault();
+            var target = Clusters[clusterB].Cluster.GetActiveSilos().Where(h => h.SiloAddress.Endpoint.Port == portsB[1]).FirstOrDefault();
             Assert.NotNull(target);
-            StopSilo(target);
+            Clusters[clusterB].Cluster.StopSilo(target);
             await WaitForLivenessToStabilizeAsync();
 
             // expect disappearance and replacement of gateway from multicluster network
             await WaitForMultiClusterGossipToStabilizeAsync(false);
             AssertSameList(clientA.GetMultiClusterGateways(), clientB.GetMultiClusterGateways());
             activegateways = clientA.GetMultiClusterGateways().Where(g => g.Status == GatewayStatus.Active).ToList();
-            Assert.Equal(string.Join(",", portA0, portA1),
+            Assert.Equal(string.Join(",", portsA[0], portsA[1]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterA).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
-            Assert.Equal(string.Join(",", portB0, portB2),
+            Assert.Equal(string.Join(",", portsB[0], portsB[2]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterB).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
      
 
             // kill one of the gateways in cluster A
-            target = Clusters[clusterA].Silos.Where(h => h.SiloAddress.Endpoint.Port == portA1).FirstOrDefault();
+            target = Clusters[clusterA].Cluster.GetActiveSilos().Where(h => h.SiloAddress.Endpoint.Port == portsA[1]).FirstOrDefault();
             Assert.NotNull(target);
-            KillSilo(target);
+            Clusters[clusterA].Cluster.KillSilo(target);
             await WaitForLivenessToStabilizeAsync();
 
             // wait for time necessary before peer removal can kick in
@@ -228,7 +224,7 @@ public async Task TestMultiClusterConf_3_3()
             while (true)
             {
                 var hosts = clientA.GetHosts();
-                var killedone = hosts.Where(kvp => kvp.Key.Endpoint.Port == portA1).FirstOrDefault();
+                var killedone = hosts.Where(kvp => kvp.Key.Endpoint.Port == portsA[1]).FirstOrDefault();
                 Assert.True(killedone.Value != SiloStatus.None);
                 if (killedone.Value == SiloStatus.Dead)
                     break;
@@ -240,9 +236,9 @@ public async Task TestMultiClusterConf_3_3()
 
             AssertSameList(clientA.GetMultiClusterGateways(), clientB.GetMultiClusterGateways());
             activegateways = clientA.GetMultiClusterGateways().Where(g => g.Status == GatewayStatus.Active).ToList();
-            Assert.Equal(string.Join(",", portA0, portA2),
+            Assert.Equal(string.Join(",", portsA[0], portsA[2]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterA).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
-            Assert.Equal(string.Join(",", portB0, portB2),
+            Assert.Equal(string.Join(",", portsB[0], portsB[2]),
                             string.Join(",", activegateways.Where(g => g.ClusterId == clusterB).Select(g => g.SiloAddress.Endpoint.Port).OrderBy(x => x)));
         }
     }
diff --git a/test/TesterInternal/GeoClusterTests/MultiClusterRegistrationTests.cs b/test/TesterInternal/GeoClusterTests/MultiClusterRegistrationTests.cs
index e624e0d9df..a86bd4acbe 100644
--- a/test/TesterInternal/GeoClusterTests/MultiClusterRegistrationTests.cs
+++ b/test/TesterInternal/GeoClusterTests/MultiClusterRegistrationTests.cs
@@ -6,7 +6,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using Tester;
 using TestExtensions;
 using TestGrainInterfaces;
 using Tests.GeoClusterTests;
@@ -92,12 +91,12 @@ public async Task FourClusterBattery()
                 await t;
         }
 
-        public Task StartClustersAndClients(params int[] silos)
+        public Task StartClustersAndClients(params short[] silos)
         {
             return StartClustersAndClients(null, null, silos);
         }
 
-        public Task StartClustersAndClients(Action<ClusterConfiguration> config_customizer, Action<ClientConfiguration> clientconfig_customizer, params int[] silos)
+        public Task StartClustersAndClients(Action<ClusterConfiguration> config_customizer, Action<ClientConfiguration> clientconfig_customizer, params short[] silos)
         {
             WriteLog("Creating clusters and clients...");
             var stopwatch = new System.Diagnostics.Stopwatch();
@@ -493,7 +492,7 @@ await RunWithTimeout("BlockedDeact", 10 * 1000, async () =>
                 AssertEqual(1, val, gref);
                 var newid = Clients[1][0].GetRuntimeId(x);
                 WriteLog("{2} sees Grain {0} at {1}", gref, newid, ClusterNames[1]);
-                Assert.True(Clusters[ClusterNames[1]].Silos[0].SiloAddress.ToString() == newid);
+                Assert.True(Clusters[ClusterNames[1]].Silos.First().SiloAddress.ToString() == newid);
             });
         }
     }
diff --git a/test/TesterInternal/GeoClusterTests/TestingClusterHost.cs b/test/TesterInternal/GeoClusterTests/TestingClusterHost.cs
index 1fdb7ba8a5..ab712cec92 100644
--- a/test/TesterInternal/GeoClusterTests/TestingClusterHost.cs
+++ b/test/TesterInternal/GeoClusterTests/TestingClusterHost.cs
@@ -1,12 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Net;
-using System.Reflection;
 using System.Threading.Tasks;
 using Orleans;
-using Orleans.Runtime;
 using Orleans.Runtime.Configuration;
 using Orleans.TestingHost;
 using Tester;
@@ -22,28 +19,23 @@ namespace Tests.GeoClusterTests
     /// </summary>
     public class TestingClusterHost : IDisposable
     {
+        public readonly Dictionary<string, ClusterInfo> Clusters = new Dictionary<string, ClusterInfo>();
 
-        protected readonly Dictionary<string, ClusterInfo> Clusters;
-        private TestingSiloHost siloHost;
-
-
-        public TestingSiloOptions siloOptions { get; set; }
         protected ITestOutputHelper output;
 
-        private TimeSpan gossipStabilizationTime;
+        private TimeSpan gossipStabilizationTime = TimeSpan.FromSeconds(10);
 
         public TestingClusterHost(ITestOutputHelper output = null)
         {
             this.output = output;
-            Clusters = new Dictionary<string, ClusterInfo>();
             TestUtils.CheckForAzureStorage();
         }
-      
 
-        protected struct ClusterInfo
+        public struct ClusterInfo
         {
-            public List<SiloHandle> Silos;  // currently active silos
+            public TestCluster Cluster;
             public int SequenceNumber; // we number created clusters in order of creation
+            public IEnumerable<SiloHandle> Silos => Cluster.GetActiveSilos();
         }
 
         public void WriteLog(string format, params object[] args)
@@ -127,7 +119,9 @@ public async Task WaitForMultiClusterGossipToStabilizeAsync(bool account_for_los
 
         public Task WaitForLivenessToStabilizeAsync()
         {
-            return this.siloHost.WaitForLivenessToStabilizeAsync();
+            return this.Clusters.Any() 
+                ? this.Clusters.First().Value.Cluster.WaitForLivenessToStabilizeAsync()
+                : Task.Delay(gossipStabilizationTime);
         }
 
         private static TimeSpan GetGossipStabilizationTime(GlobalConfiguration global)
@@ -139,18 +133,12 @@ private static TimeSpan GetGossipStabilizationTime(GlobalConfiguration global)
             return stabilizationTime;
         }
 
-        public void StopSilo(SiloHandle instance)
-        {
-            siloHost.StopSilo(instance);
-        }
-        public void KillSilo(SiloHandle instance)
-        {
-            siloHost.KillSilo(instance);
-        }
-
         public void StopAllSilos()
         {
-            siloHost.StopAllSilos();
+            foreach (var cluster in Clusters.Values)
+            {
+                cluster.Cluster.StopAllSilos();
+            }
         }
 
         public ParallelOptions paralleloptions = new ParallelOptions() { MaxDegreeOfParallelism = 4 };
@@ -170,7 +158,7 @@ private static int GetProxyBase(int clusternumber)
 
         #region Cluster Creation
 
-        public void NewGeoCluster(Guid globalServiceId, string clusterId, int numSilos, Action<ClusterConfiguration> customizer = null)
+        public void NewGeoCluster(Guid globalServiceId, string clusterId, short numSilos, Action<ClusterConfiguration> customizer = null)
         {
             Action<ClusterConfiguration> extendedcustomizer = config =>
                 {
@@ -194,61 +182,40 @@ public void NewGeoCluster(Guid globalServiceId, string clusterId, int numSilos,
         }
 
 
-        public void NewCluster(string clusterId, int numSilos, Action<ClusterConfiguration> customizer = null)
+        public void NewCluster(string clusterId, short numSilos, Action<ClusterConfiguration> customizer = null)
         {
+            TestCluster testCluster;
             lock (Clusters)
             {
                 var myCount = Clusters.Count;
 
                 WriteLog("Starting Cluster {0}  ({1})...", myCount, clusterId);
 
-                if (myCount == 0)
+                var options = new TestClusterOptions(initialSilosCount: numSilos)
                 {
-                    TestingSiloHost.StopAllSilosIfRunning();
-                    this.siloHost = TestingSiloHost.CreateUninitialized();
-                }
-
-                var silohandles = new SiloHandle[numSilos];
-
-                var options = new TestingSiloOptions
-                {
-                    StartClient = false,
-                    AdjustConfig = customizer,
-                    BasePort = GetPortBase(myCount),
-                    ProxyBasePort = GetProxyBase(myCount)
+                    BaseSiloPort = GetPortBase(myCount),
+                    BaseGatewayPort = GetProxyBase(myCount)
                 };
-                silohandles[0] = TestingSiloHost.StartOrleansSilo(this.siloHost, Silo.SiloType.Primary, options, 0);
+                options.ClusterConfiguration.AddMemoryStorageProvider("Default");
+                options.ClusterConfiguration.AddMemoryStorageProvider("MemoryStore");
 
-                Parallel.For(1, numSilos, paralleloptions, i =>
-                {
-                    silohandles[i] = TestingSiloHost.StartOrleansSilo(this.siloHost, Silo.SiloType.Secondary, options, i);
-                });
+                customizer?.Invoke(options.ClusterConfiguration);
+                testCluster = new TestCluster(options.ClusterConfiguration, null);
+                testCluster.Deploy();
 
                 Clusters[clusterId] = new ClusterInfo
                 {
-                    Silos = silohandles.ToList(),
+                    Cluster = testCluster,
                     SequenceNumber = myCount
                 };
 
                 if (myCount == 0)
-                    gossipStabilizationTime = GetGossipStabilizationTime(this.siloHost.Globals);
+                    gossipStabilizationTime = GetGossipStabilizationTime(options.ClusterConfiguration.Globals);
 
-                WriteLog("Cluster {0} started. [{1}]", clusterId, string.Join(" ", silohandles.Select(s => s.ToString())));
+                WriteLog("Cluster {0} started. [{1}]", clusterId, string.Join(" ", testCluster.GetActiveSilos().Select(s => s.ToString())));
             }
         }
 
-        public void AddSiloToCluster(string clusterId, string siloName, Action<ClusterConfiguration> customizer = null)
-        {
-            var clusterinfo = Clusters[clusterId];
-
-            var options = new TestingSiloOptions
-            {
-                StartClient = false,
-                AdjustConfig = customizer
-            };
-
-            var silo = TestingSiloHost.StartOrleansSilo(this.siloHost, Silo.SiloType.Secondary, options, clusterinfo.Silos.Count);
-        }
         public virtual void Dispose()
         {
             StopAllClientsAndClusters();
@@ -289,8 +256,7 @@ public void StopAllClusters()
                 Parallel.ForEach(Clusters.Keys, paralleloptions, key =>
                 {
                     var info = Clusters[key];
-                    Parallel.For(1, info.Silos.Count, i => siloHost.StopSilo(info.Silos[i]));
-                    siloHost.StopSilo(info.Silos[0]);
+                    info.Cluster.StopAllSilos();
                 });
                 Clusters.Clear();
             }
@@ -362,7 +328,7 @@ public T NewClient<T>(
             var name = string.Format("Client-{0}-{1}", clusterId, clientNumber);
 
             // clients are assigned to silos round-robin
-            var gatewayport = ci.Silos[clientNumber % ci.Silos.Count].NodeConfiguration.ProxyGatewayEndpoint.Port;
+            var gatewayport = ci.Silos.ElementAt(clientNumber).ProxyAddress.Endpoint.Port;
 
             WriteLog("Starting {0} connected to {1}", name, gatewayport);
             
@@ -438,7 +404,7 @@ public void SetProtocolMessageFilterForTesting(string origincluster, Func<ILogCo
         private SiloHandle GetActiveSiloInClusterByName(string clusterId, string siloName)
         {
             if (Clusters[clusterId].Silos == null) return null;
-            return Clusters[clusterId].Silos.Find(s => s.Name == siloName);
+            return Clusters[clusterId].Cluster.GetActiveSilos().FirstOrDefault(s => s.Name == siloName);
         }
     }
 }
\ No newline at end of file
diff --git a/vNext/test/TesterInternal/TesterInternal.csproj b/vNext/test/TesterInternal/TesterInternal.csproj
index baeb1bdc35..f6a3aeabfd 100644
--- a/vNext/test/TesterInternal/TesterInternal.csproj
+++ b/vNext/test/TesterInternal/TesterInternal.csproj
@@ -51,7 +51,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="..\..\..\test\TesterInternal\**\*.cs" Exclude="..\..\..\test\TesterInternal\obj\**\*.cs;..\..\..\test\TesterInternal\bin\**\*.cs;..\..\..\test\TesterInternal\Properties\*.cs;..\..\..\test\TesterInternal\CounterControlProgTests.cs;..\..\..\test\TesterInternal\GeoClusterTests\*.cs;..\..\..\test\TesterInternal\HostedTestClusterBase.cs;..\..\..\test\TesterInternal\OrleansHostProgTests.cs" />
+    <Compile Include="..\..\..\test\TesterInternal\**\*.cs" Exclude="..\..\..\test\TesterInternal\obj\**\*.cs;..\..\..\test\TesterInternal\bin\**\*.cs;..\..\..\test\TesterInternal\Properties\*.cs;..\..\..\test\TesterInternal\CounterControlProgTests.cs;..\..\..\test\TesterInternal\GeoClusterTests\*.cs;..\..\..\test\TesterInternal\OrleansHostProgTests.cs" />
   </ItemGroup>
 
   <ItemGroup>