fix: exclude shutting down silos from placement

src/Orleans.Core/Core/GrainInterfaceTypeToGrainTypeResolver.cs

@@ -205,56 +205,62 @@ private static Cache BuildCache(ClusterManifest clusterManifest)
 
             foreach (var manifest in clusterManifest.AllGrainManifests)
             {
-                foreach (var grainType in manifest.Grains)
+                AddManifest(result, manifest);
+            }
+
+            return new Cache(clusterManifest.Version, result);
+        }
+
+        private static void AddManifest(Dictionary<GrainInterfaceType, CacheEntry> result, GrainManifest manifest)
+        {
+            foreach (var grainType in manifest.Grains)
+            {
+                var id = grainType.Key;
+                grainType.Value.Properties.TryGetValue(WellKnownGrainTypeProperties.TypeName, out var typeName);
+                grainType.Value.Properties.TryGetValue(WellKnownGrainTypeProperties.FullTypeName, out var fullTypeName);
+                foreach (var property in grainType.Value.Properties)
                 {
-                    var id = grainType.Key;
-                    grainType.Value.Properties.TryGetValue(WellKnownGrainTypeProperties.TypeName, out var typeName);
-                    grainType.Value.Properties.TryGetValue(WellKnownGrainTypeProperties.FullTypeName, out var fullTypeName);
-                    foreach (var property in grainType.Value.Properties)
+                    if (!property.Key.StartsWith(WellKnownGrainTypeProperties.ImplementedInterfacePrefix, StringComparison.Ordinal)) continue;
+                    var implemented = GrainInterfaceType.Create(property.Value);
+                    string interfaceTypeName;
+                    if (manifest.Interfaces.TryGetValue(implemented, out var interfaceProperties))
                     {
-                        if (!property.Key.StartsWith(WellKnownGrainTypeProperties.ImplementedInterfacePrefix, StringComparison.Ordinal)) continue;
-                        var implemented = GrainInterfaceType.Create(property.Value);
-                        string interfaceTypeName;
-                        if (manifest.Interfaces.TryGetValue(implemented, out var interfaceProperties))
-                        {
-                            interfaceProperties.Properties.TryGetValue(WellKnownGrainInterfaceProperties.TypeName, out interfaceTypeName);
-                        }
-                        else
-                        {
-                            interfaceTypeName = null;
-                        }
+                        interfaceProperties.Properties.TryGetValue(WellKnownGrainInterfaceProperties.TypeName, out interfaceTypeName);
+                    }
+                    else
+                    {
+                        interfaceTypeName = null;
+                    }
 
-                        // Try to work out the best primary implementation
-                        result.TryGetValue(implemented, out var entry);
+                    // Try to work out the best primary implementation
+                    result.TryGetValue(implemented, out var entry);
 
-                        var implementations = entry.Implementations ?? new List<(string Prefix, GrainType GrainType)>();
-                        if (!implementations.Contains((fullTypeName, id))) implementations.Add((fullTypeName, id));
+                    var implementations = entry.Implementations ?? new List<(string Prefix, GrainType GrainType)>();
+                    if (!implementations.Contains((fullTypeName, id))) implementations.Add((fullTypeName, id));
 
-                        GrainType primaryImplementation;
-                        if (!entry.PrimaryImplementation.IsDefault)
-                        {
-                            primaryImplementation = entry.PrimaryImplementation;
-                        }
-                        else if (interfaceProperties?.Properties is { } props && props.TryGetValue(WellKnownGrainInterfaceProperties.DefaultGrainType, out var defaultTypeString))
-                        {
-                            // A specified default grain type trumps others.
-                            primaryImplementation = GrainType.Create(defaultTypeString);
-                        }
-                        else if (string.Equals(interfaceTypeName?[1..], typeName, StringComparison.Ordinal))
-                        {
-                            // Otherwise, a substring match on the interface name, dropping the 'I', is used.
-                            primaryImplementation = id;
-                        }
-                        else
-                        {
-                            primaryImplementation = default;
-                        }
-                        result[implemented] = new CacheEntry(primaryImplementation, implementations);
+                    GrainType primaryImplementation;
+                    if (!entry.PrimaryImplementation.IsDefault)
+                    {
+                        primaryImplementation = entry.PrimaryImplementation;
+                    }
+                    else if (interfaceProperties?.Properties is { } props && props.TryGetValue(WellKnownGrainInterfaceProperties.DefaultGrainType, out var defaultTypeString))
+                    {
+                        // A specified default grain type trumps others.
+                        primaryImplementation = GrainType.Create(defaultTypeString);
+                    }
+                    else if (string.Equals(interfaceTypeName?[1..], typeName, StringComparison.Ordinal))
+                    {
+                        // Otherwise, a substring match on the interface name, dropping the 'I', is used.
+                        primaryImplementation = id;
                     }
+                    else
+                    {
+                        primaryImplementation = default;
+                    }
+
+                    result[implemented] = new CacheEntry(primaryImplementation, implementations);
                 }
             }
-
-            return new Cache(clusterManifest.Version, result);
         }
 
         /// <summary>

src/Orleans.Core/Manifest/GrainBindings.cs

@@ -134,6 +134,13 @@ private static Cache BuildCache(ClusterManifest clusterManifest)
 
             var bindings = new Dictionary<string, Dictionary<string, string>>();
             foreach (var manifest in clusterManifest.AllGrainManifests)
+            {
+                AddManifest(manifest);
+            }
+
+            return new Cache(clusterManifest.Version, result.ToImmutableDictionary());
+
+            void AddManifest(GrainManifest manifest)
             {
                 foreach (var grainType in manifest.Grains)
                 {
@@ -163,8 +170,6 @@ private static Cache BuildCache(ClusterManifest clusterManifest)
                 }
             }
 
-            return new Cache(clusterManifest.Version, result.ToImmutableDictionary());
-
             bool TryExtractBindingProperty(KeyValuePair<string, string> property, out (string Index, string Key, string Value) result)
             {
                 if (!property.Key.StartsWith(BindingPrefix, StringComparison.Ordinal)

src/Orleans.Core/Placement/IPlacementContext.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Collections.Immutable;
 
 namespace Orleans.Runtime.Placement
 {
@@ -14,7 +15,7 @@ public interface IPlacementContext
         /// A description of the grain being placed as well as contextual information about the request which is triggering placement.
         /// </param>
         /// <returns>The collection of silos which are compatible with the provided placement target.</returns>
-        SiloAddress[] GetCompatibleSilos(PlacementTarget target);
+        ImmutableArray<SiloAddress> GetCompatibleSilos(PlacementTarget target);
 
         /// <summary>
         /// Gets the collection of silos which are compatible with the provided placement target, along with the versions of the grain interface which each server supports.

src/Orleans.Core/Placement/IPlacementDirector.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Threading.Tasks;
 
@@ -31,7 +32,7 @@ Task<SiloAddress> OnAddActivation(
         /// <param name="requestContextData">The request context data.</param>
         /// <param name="compatibleSilos">The compatible silos.</param>
         /// <returns>The placement hint, if present and valid, or <see landword="null"/> otherwise.</returns>
-        public static SiloAddress GetPlacementHint(Dictionary<string, object> requestContextData, SiloAddress[] compatibleSilos)
+        public static SiloAddress GetPlacementHint(Dictionary<string, object> requestContextData, ImmutableArray<SiloAddress> compatibleSilos)
         {
             if (requestContextData is { Count: > 0 } data
                 && data.TryGetValue(PlacementHintKey, out var value)