diff --git a/src/csharp/Grpc.Examples/MathGrpc.cs b/src/csharp/Grpc.Examples/MathGrpc.cs
index 4ed4144..e29b108 100644
--- a/src/csharp/Grpc.Examples/MathGrpc.cs
+++ b/src/csharp/Grpc.Examples/MathGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: math/math.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: math/math.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
diff --git a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
index 3e8eb34..24a7259 100644
--- a/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
+++ b/src/csharp/Grpc.HealthCheck/HealthGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: grpc/health/v1/health.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: grpc/health/v1/health.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
diff --git a/src/csharp/Grpc.IntegrationTesting/Control.cs b/src/csharp/Grpc.IntegrationTesting/Control.cs
index b15da8b..8e5da7b 100644
--- a/src/csharp/Grpc.IntegrationTesting/Control.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Control.cs
@@ -522,10 +522,16 @@
       }
       switch (other.LoadCase) {
         case LoadOneofCase.ClosedLoop:
-          ClosedLoop = other.ClosedLoop;
+          if (ClosedLoop == null) {
+            ClosedLoop = new global::Grpc.Testing.ClosedLoopParams();
+          }
+          ClosedLoop.MergeFrom(other.ClosedLoop);
           break;
         case LoadOneofCase.Poisson:
-          Poisson = other.Poisson;
+          if (Poisson == null) {
+            Poisson = new global::Grpc.Testing.PoissonParams();
+          }
+          Poisson.MergeFrom(other.Poisson);
           break;
       }
 
@@ -1901,10 +1907,16 @@
       }
       switch (other.ArgtypeCase) {
         case ArgtypeOneofCase.Setup:
-          Setup = other.Setup;
+          if (Setup == null) {
+            Setup = new global::Grpc.Testing.ClientConfig();
+          }
+          Setup.MergeFrom(other.Setup);
           break;
         case ArgtypeOneofCase.Mark:
-          Mark = other.Mark;
+          if (Mark == null) {
+            Mark = new global::Grpc.Testing.Mark();
+          }
+          Mark.MergeFrom(other.Mark);
           break;
       }
 
@@ -2508,10 +2520,16 @@
       }
       switch (other.ArgtypeCase) {
         case ArgtypeOneofCase.Setup:
-          Setup = other.Setup;
+          if (Setup == null) {
+            Setup = new global::Grpc.Testing.ServerConfig();
+          }
+          Setup.MergeFrom(other.Setup);
           break;
         case ArgtypeOneofCase.Mark:
-          Mark = other.Mark;
+          if (Mark == null) {
+            Mark = new global::Grpc.Testing.Mark();
+          }
+          Mark.MergeFrom(other.Mark);
           break;
       }
 
diff --git a/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs b/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs
new file mode 100644
index 0000000..380294e
--- /dev/null
+++ b/src/csharp/Grpc.IntegrationTesting/CoreStats/Stats.cs
@@ -0,0 +1,623 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: grpc/core/stats.proto
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace Grpc.Core {
+
+  /// <summary>Holder for reflection information generated from grpc/core/stats.proto</summary>
+  public static partial class StatsReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for grpc/core/stats.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static StatsReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "ChVncnBjL2NvcmUvc3RhdHMucHJvdG8SCWdycGMuY29yZSImCgZCdWNrZXQS",
+            "DQoFc3RhcnQYASABKAESDQoFY291bnQYAiABKAQiLwoJSGlzdG9ncmFtEiIK",
+            "B2J1Y2tldHMYASADKAsyES5ncnBjLmNvcmUuQnVja2V0IlsKBk1ldHJpYxIM",
+            "CgRuYW1lGAEgASgJEg8KBWNvdW50GAogASgESAASKQoJaGlzdG9ncmFtGAsg",
+            "ASgLMhQuZ3JwYy5jb3JlLkhpc3RvZ3JhbUgAQgcKBXZhbHVlIisKBVN0YXRz",
+            "EiIKB21ldHJpY3MYASADKAsyES5ncnBjLmNvcmUuTWV0cmljYgZwcm90bzM="));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { },
+          new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Core.Bucket), global::Grpc.Core.Bucket.Parser, new[]{ "Start", "Count" }, null, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Core.Histogram), global::Grpc.Core.Histogram.Parser, new[]{ "Buckets" }, null, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Core.Metric), global::Grpc.Core.Metric.Parser, new[]{ "Name", "Count", "Histogram" }, new[]{ "Value" }, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Core.Stats), global::Grpc.Core.Stats.Parser, new[]{ "Metrics" }, null, null, null)
+          }));
+    }
+    #endregion
+
+  }
+  #region Messages
+  public sealed partial class Bucket : pb::IMessage<Bucket> {
+    private static readonly pb::MessageParser<Bucket> _parser = new pb::MessageParser<Bucket>(() => new Bucket());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<Bucket> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Grpc.Core.StatsReflection.Descriptor.MessageTypes[0]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Bucket() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Bucket(Bucket other) : this() {
+      start_ = other.start_;
+      count_ = other.count_;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Bucket Clone() {
+      return new Bucket(this);
+    }
+
+    /// <summary>Field number for the "start" field.</summary>
+    public const int StartFieldNumber = 1;
+    private double start_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public double Start {
+      get { return start_; }
+      set {
+        start_ = value;
+      }
+    }
+
+    /// <summary>Field number for the "count" field.</summary>
+    public const int CountFieldNumber = 2;
+    private ulong count_;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public ulong Count {
+      get { return count_; }
+      set {
+        count_ = value;
+      }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as Bucket);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(Bucket other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if (Start != other.Start) return false;
+      if (Count != other.Count) return false;
+      return true;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      if (Start != 0D) hash ^= Start.GetHashCode();
+      if (Count != 0UL) hash ^= Count.GetHashCode();
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+      if (Start != 0D) {
+        output.WriteRawTag(9);
+        output.WriteDouble(Start);
+      }
+      if (Count != 0UL) {
+        output.WriteRawTag(16);
+        output.WriteUInt64(Count);
+      }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      if (Start != 0D) {
+        size += 1 + 8;
+      }
+      if (Count != 0UL) {
+        size += 1 + pb::CodedOutputStream.ComputeUInt64Size(Count);
+      }
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(Bucket other) {
+      if (other == null) {
+        return;
+      }
+      if (other.Start != 0D) {
+        Start = other.Start;
+      }
+      if (other.Count != 0UL) {
+        Count = other.Count;
+      }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 9: {
+            Start = input.ReadDouble();
+            break;
+          }
+          case 16: {
+            Count = input.ReadUInt64();
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
+  public sealed partial class Histogram : pb::IMessage<Histogram> {
+    private static readonly pb::MessageParser<Histogram> _parser = new pb::MessageParser<Histogram>(() => new Histogram());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<Histogram> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Grpc.Core.StatsReflection.Descriptor.MessageTypes[1]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Histogram() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Histogram(Histogram other) : this() {
+      buckets_ = other.buckets_.Clone();
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Histogram Clone() {
+      return new Histogram(this);
+    }
+
+    /// <summary>Field number for the "buckets" field.</summary>
+    public const int BucketsFieldNumber = 1;
+    private static readonly pb::FieldCodec<global::Grpc.Core.Bucket> _repeated_buckets_codec
+        = pb::FieldCodec.ForMessage(10, global::Grpc.Core.Bucket.Parser);
+    private readonly pbc::RepeatedField<global::Grpc.Core.Bucket> buckets_ = new pbc::RepeatedField<global::Grpc.Core.Bucket>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public pbc::RepeatedField<global::Grpc.Core.Bucket> Buckets {
+      get { return buckets_; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as Histogram);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(Histogram other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if(!buckets_.Equals(other.buckets_)) return false;
+      return true;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      hash ^= buckets_.GetHashCode();
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+      buckets_.WriteTo(output, _repeated_buckets_codec);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      size += buckets_.CalculateSize(_repeated_buckets_codec);
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(Histogram other) {
+      if (other == null) {
+        return;
+      }
+      buckets_.Add(other.buckets_);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            buckets_.AddEntriesFrom(input, _repeated_buckets_codec);
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
+  public sealed partial class Metric : pb::IMessage<Metric> {
+    private static readonly pb::MessageParser<Metric> _parser = new pb::MessageParser<Metric>(() => new Metric());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<Metric> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Grpc.Core.StatsReflection.Descriptor.MessageTypes[2]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Metric() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Metric(Metric other) : this() {
+      name_ = other.name_;
+      switch (other.ValueCase) {
+        case ValueOneofCase.Count:
+          Count = other.Count;
+          break;
+        case ValueOneofCase.Histogram:
+          Histogram = other.Histogram.Clone();
+          break;
+      }
+
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Metric Clone() {
+      return new Metric(this);
+    }
+
+    /// <summary>Field number for the "name" field.</summary>
+    public const int NameFieldNumber = 1;
+    private string name_ = "";
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public string Name {
+      get { return name_; }
+      set {
+        name_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    /// <summary>Field number for the "count" field.</summary>
+    public const int CountFieldNumber = 10;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public ulong Count {
+      get { return valueCase_ == ValueOneofCase.Count ? (ulong) value_ : 0UL; }
+      set {
+        value_ = value;
+        valueCase_ = ValueOneofCase.Count;
+      }
+    }
+
+    /// <summary>Field number for the "histogram" field.</summary>
+    public const int HistogramFieldNumber = 11;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public global::Grpc.Core.Histogram Histogram {
+      get { return valueCase_ == ValueOneofCase.Histogram ? (global::Grpc.Core.Histogram) value_ : null; }
+      set {
+        value_ = value;
+        valueCase_ = value == null ? ValueOneofCase.None : ValueOneofCase.Histogram;
+      }
+    }
+
+    private object value_;
+    /// <summary>Enum of possible cases for the "value" oneof.</summary>
+    public enum ValueOneofCase {
+      None = 0,
+      Count = 10,
+      Histogram = 11,
+    }
+    private ValueOneofCase valueCase_ = ValueOneofCase.None;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public ValueOneofCase ValueCase {
+      get { return valueCase_; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void ClearValue() {
+      valueCase_ = ValueOneofCase.None;
+      value_ = null;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as Metric);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(Metric other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if (Name != other.Name) return false;
+      if (Count != other.Count) return false;
+      if (!object.Equals(Histogram, other.Histogram)) return false;
+      if (ValueCase != other.ValueCase) return false;
+      return true;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (valueCase_ == ValueOneofCase.Count) hash ^= Count.GetHashCode();
+      if (valueCase_ == ValueOneofCase.Histogram) hash ^= Histogram.GetHashCode();
+      hash ^= (int) valueCase_;
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+      if (Name.Length != 0) {
+        output.WriteRawTag(10);
+        output.WriteString(Name);
+      }
+      if (valueCase_ == ValueOneofCase.Count) {
+        output.WriteRawTag(80);
+        output.WriteUInt64(Count);
+      }
+      if (valueCase_ == ValueOneofCase.Histogram) {
+        output.WriteRawTag(90);
+        output.WriteMessage(Histogram);
+      }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      if (Name.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
+      }
+      if (valueCase_ == ValueOneofCase.Count) {
+        size += 1 + pb::CodedOutputStream.ComputeUInt64Size(Count);
+      }
+      if (valueCase_ == ValueOneofCase.Histogram) {
+        size += 1 + pb::CodedOutputStream.ComputeMessageSize(Histogram);
+      }
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(Metric other) {
+      if (other == null) {
+        return;
+      }
+      if (other.Name.Length != 0) {
+        Name = other.Name;
+      }
+      switch (other.ValueCase) {
+        case ValueOneofCase.Count:
+          Count = other.Count;
+          break;
+        case ValueOneofCase.Histogram:
+          if (Histogram == null) {
+            Histogram = new global::Grpc.Core.Histogram();
+          }
+          Histogram.MergeFrom(other.Histogram);
+          break;
+      }
+
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            Name = input.ReadString();
+            break;
+          }
+          case 80: {
+            Count = input.ReadUInt64();
+            break;
+          }
+          case 90: {
+            global::Grpc.Core.Histogram subBuilder = new global::Grpc.Core.Histogram();
+            if (valueCase_ == ValueOneofCase.Histogram) {
+              subBuilder.MergeFrom(Histogram);
+            }
+            input.ReadMessage(subBuilder);
+            Histogram = subBuilder;
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
+  public sealed partial class Stats : pb::IMessage<Stats> {
+    private static readonly pb::MessageParser<Stats> _parser = new pb::MessageParser<Stats>(() => new Stats());
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<Stats> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Grpc.Core.StatsReflection.Descriptor.MessageTypes[3]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Stats() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Stats(Stats other) : this() {
+      metrics_ = other.metrics_.Clone();
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public Stats Clone() {
+      return new Stats(this);
+    }
+
+    /// <summary>Field number for the "metrics" field.</summary>
+    public const int MetricsFieldNumber = 1;
+    private static readonly pb::FieldCodec<global::Grpc.Core.Metric> _repeated_metrics_codec
+        = pb::FieldCodec.ForMessage(10, global::Grpc.Core.Metric.Parser);
+    private readonly pbc::RepeatedField<global::Grpc.Core.Metric> metrics_ = new pbc::RepeatedField<global::Grpc.Core.Metric>();
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public pbc::RepeatedField<global::Grpc.Core.Metric> Metrics {
+      get { return metrics_; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as Stats);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(Stats other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if(!metrics_.Equals(other.metrics_)) return false;
+      return true;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      hash ^= metrics_.GetHashCode();
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+      metrics_.WriteTo(output, _repeated_metrics_codec);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      size += metrics_.CalculateSize(_repeated_metrics_codec);
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(Stats other) {
+      if (other == null) {
+        return;
+      }
+      metrics_.Add(other.metrics_);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            metrics_.AddEntriesFrom(input, _repeated_metrics_codec);
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
+  #endregion
+
+}
+
+#endregion Designer generated code
diff --git a/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs b/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
index b2fe73a..9581ade 100644
--- a/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
+++ b/src/csharp/Grpc.IntegrationTesting/EchoMessages.cs
@@ -26,7 +26,7 @@
             "DGdycGMudGVzdGluZyIyCglEZWJ1Z0luZm8SFQoNc3RhY2tfZW50cmllcxgB",
             "IAMoCRIOCgZkZXRhaWwYAiABKAkiUAoLRXJyb3JTdGF0dXMSDAoEY29kZRgB",
             "IAEoBRIVCg1lcnJvcl9tZXNzYWdlGAIgASgJEhwKFGJpbmFyeV9lcnJvcl9k",
-            "ZXRhaWxzGAMgASgJIskDCg1SZXF1ZXN0UGFyYW1zEhUKDWVjaG9fZGVhZGxp",
+            "ZXRhaWxzGAMgASgJIuIDCg1SZXF1ZXN0UGFyYW1zEhUKDWVjaG9fZGVhZGxp",
             "bmUYASABKAgSHgoWY2xpZW50X2NhbmNlbF9hZnRlcl91cxgCIAEoBRIeChZz",
             "ZXJ2ZXJfY2FuY2VsX2FmdGVyX3VzGAMgASgFEhUKDWVjaG9fbWV0YWRhdGEY",
             "BCABKAgSGgoSY2hlY2tfYXV0aF9jb250ZXh0GAUgASgIEh8KF3Jlc3BvbnNl",
@@ -36,18 +36,19 @@
             "X3R5cGUYCiABKAkSKwoKZGVidWdfaW5mbxgLIAEoCzIXLmdycGMudGVzdGlu",
             "Zy5EZWJ1Z0luZm8SEgoKc2VydmVyX2RpZRgMIAEoCBIcChRiaW5hcnlfZXJy",
             "b3JfZGV0YWlscxgNIAEoCRIxCg5leHBlY3RlZF9lcnJvchgOIAEoCzIZLmdy",
-            "cGMudGVzdGluZy5FcnJvclN0YXR1cyJKCgtFY2hvUmVxdWVzdBIPCgdtZXNz",
-            "YWdlGAEgASgJEioKBXBhcmFtGAIgASgLMhsuZ3JwYy50ZXN0aW5nLlJlcXVl",
-            "c3RQYXJhbXMiRgoOUmVzcG9uc2VQYXJhbXMSGAoQcmVxdWVzdF9kZWFkbGlu",
-            "ZRgBIAEoAxIMCgRob3N0GAIgASgJEgwKBHBlZXIYAyABKAkiTAoMRWNob1Jl",
-            "c3BvbnNlEg8KB21lc3NhZ2UYASABKAkSKwoFcGFyYW0YAiABKAsyHC5ncnBj",
-            "LnRlc3RpbmcuUmVzcG9uc2VQYXJhbXNiBnByb3RvMw=="));
+            "cGMudGVzdGluZy5FcnJvclN0YXR1cxIXCg9zZXJ2ZXJfc2xlZXBfdXMYDyAB",
+            "KAUiSgoLRWNob1JlcXVlc3QSDwoHbWVzc2FnZRgBIAEoCRIqCgVwYXJhbRgC",
+            "IAEoCzIbLmdycGMudGVzdGluZy5SZXF1ZXN0UGFyYW1zIkYKDlJlc3BvbnNl",
+            "UGFyYW1zEhgKEHJlcXVlc3RfZGVhZGxpbmUYASABKAMSDAoEaG9zdBgCIAEo",
+            "CRIMCgRwZWVyGAMgASgJIkwKDEVjaG9SZXNwb25zZRIPCgdtZXNzYWdlGAEg",
+            "ASgJEisKBXBhcmFtGAIgASgLMhwuZ3JwYy50ZXN0aW5nLlJlc3BvbnNlUGFy",
+            "YW1zYgZwcm90bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.DebugInfo), global::Grpc.Testing.DebugInfo.Parser, new[]{ "StackEntries", "Detail" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ErrorStatus), global::Grpc.Testing.ErrorStatus.Parser, new[]{ "Code", "ErrorMessage", "BinaryErrorDetails" }, null, null, null),
-            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.RequestParams), global::Grpc.Testing.RequestParams.Parser, new[]{ "EchoDeadline", "ClientCancelAfterUs", "ServerCancelAfterUs", "EchoMetadata", "CheckAuthContext", "ResponseMessageLength", "EchoPeer", "ExpectedClientIdentity", "SkipCancelledCheck", "ExpectedTransportSecurityType", "DebugInfo", "ServerDie", "BinaryErrorDetails", "ExpectedError" }, null, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.RequestParams), global::Grpc.Testing.RequestParams.Parser, new[]{ "EchoDeadline", "ClientCancelAfterUs", "ServerCancelAfterUs", "EchoMetadata", "CheckAuthContext", "ResponseMessageLength", "EchoPeer", "ExpectedClientIdentity", "SkipCancelledCheck", "ExpectedTransportSecurityType", "DebugInfo", "ServerDie", "BinaryErrorDetails", "ExpectedError", "ServerSleepUs" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.EchoRequest), global::Grpc.Testing.EchoRequest.Parser, new[]{ "Message", "Param" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ResponseParams), global::Grpc.Testing.ResponseParams.Parser, new[]{ "RequestDeadline", "Host", "Peer" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.EchoResponse), global::Grpc.Testing.EchoResponse.Parser, new[]{ "Message", "Param" }, null, null, null)
@@ -411,6 +412,7 @@
       serverDie_ = other.serverDie_;
       binaryErrorDetails_ = other.binaryErrorDetails_;
       ExpectedError = other.expectedError_ != null ? other.ExpectedError.Clone() : null;
+      serverSleepUs_ = other.serverSleepUs_;
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -578,6 +580,20 @@
       }
     }
 
+    /// <summary>Field number for the "server_sleep_us" field.</summary>
+    public const int ServerSleepUsFieldNumber = 15;
+    private int serverSleepUs_;
+    /// <summary>
+    /// Amount to sleep when invoking server
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int ServerSleepUs {
+      get { return serverSleepUs_; }
+      set {
+        serverSleepUs_ = value;
+      }
+    }
+
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as RequestParams);
@@ -605,6 +621,7 @@
       if (ServerDie != other.ServerDie) return false;
       if (BinaryErrorDetails != other.BinaryErrorDetails) return false;
       if (!object.Equals(ExpectedError, other.ExpectedError)) return false;
+      if (ServerSleepUs != other.ServerSleepUs) return false;
       return true;
     }
 
@@ -625,6 +642,7 @@
       if (ServerDie != false) hash ^= ServerDie.GetHashCode();
       if (BinaryErrorDetails.Length != 0) hash ^= BinaryErrorDetails.GetHashCode();
       if (expectedError_ != null) hash ^= ExpectedError.GetHashCode();
+      if (ServerSleepUs != 0) hash ^= ServerSleepUs.GetHashCode();
       return hash;
     }
 
@@ -691,6 +709,10 @@
         output.WriteRawTag(114);
         output.WriteMessage(ExpectedError);
       }
+      if (ServerSleepUs != 0) {
+        output.WriteRawTag(120);
+        output.WriteInt32(ServerSleepUs);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -738,6 +760,9 @@
       if (expectedError_ != null) {
         size += 1 + pb::CodedOutputStream.ComputeMessageSize(ExpectedError);
       }
+      if (ServerSleepUs != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeInt32Size(ServerSleepUs);
+      }
       return size;
     }
 
@@ -794,6 +819,9 @@
         }
         ExpectedError.MergeFrom(other.ExpectedError);
       }
+      if (other.ServerSleepUs != 0) {
+        ServerSleepUs = other.ServerSleepUs;
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -866,6 +894,10 @@
             input.ReadMessage(expectedError_);
             break;
           }
+          case 120: {
+            ServerSleepUs = input.ReadInt32();
+            break;
+          }
         }
       }
     }
diff --git a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
index 9a664f3..f71d6d1 100644
--- a/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/MetricsGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/metrics.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/metrics.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015-2016 gRPC authors.
 //
diff --git a/src/csharp/Grpc.IntegrationTesting/Payloads.cs b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
index f918b95..fca8cda 100644
--- a/src/csharp/Grpc.IntegrationTesting/Payloads.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Payloads.cs
@@ -596,13 +596,22 @@
       }
       switch (other.PayloadCase) {
         case PayloadOneofCase.BytebufParams:
-          BytebufParams = other.BytebufParams;
+          if (BytebufParams == null) {
+            BytebufParams = new global::Grpc.Testing.ByteBufferParams();
+          }
+          BytebufParams.MergeFrom(other.BytebufParams);
           break;
         case PayloadOneofCase.SimpleParams:
-          SimpleParams = other.SimpleParams;
+          if (SimpleParams == null) {
+            SimpleParams = new global::Grpc.Testing.SimpleProtoParams();
+          }
+          SimpleParams.MergeFrom(other.SimpleParams);
           break;
         case PayloadOneofCase.ComplexParams:
-          ComplexParams = other.ComplexParams;
+          if (ComplexParams == null) {
+            ComplexParams = new global::Grpc.Testing.ComplexProtoParams();
+          }
+          ComplexParams.MergeFrom(other.ComplexParams);
           break;
       }
 
diff --git a/src/csharp/Grpc.IntegrationTesting/Services.cs b/src/csharp/Grpc.IntegrationTesting/Services.cs
index 7a0845d..4b76170 100644
--- a/src/csharp/Grpc.IntegrationTesting/Services.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Services.cs
@@ -24,28 +24,27 @@
           string.Concat(
             "CiVzcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL3NlcnZpY2VzLnByb3RvEgxncnBj",
             "LnRlc3RpbmcaJXNyYy9wcm90by9ncnBjL3Rlc3RpbmcvbWVzc2FnZXMucHJv",
-            "dG8aJHNyYy9wcm90by9ncnBjL3Rlc3RpbmcvY29udHJvbC5wcm90bxoic3Jj",
-            "L3Byb3RvL2dycGMvdGVzdGluZy9zdGF0cy5wcm90bzKmAwoQQmVuY2htYXJr",
-            "U2VydmljZRJGCglVbmFyeUNhbGwSGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVx",
-            "dWVzdBocLmdycGMudGVzdGluZy5TaW1wbGVSZXNwb25zZRJOCg1TdHJlYW1p",
-            "bmdDYWxsEhsuZ3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3QaHC5ncnBjLnRl",
-            "c3RpbmcuU2ltcGxlUmVzcG9uc2UoATABElIKE1N0cmVhbWluZ0Zyb21DbGll",
-            "bnQSGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdycGMudGVzdGlu",
-            "Zy5TaW1wbGVSZXNwb25zZSgBElIKE1N0cmVhbWluZ0Zyb21TZXJ2ZXISGy5n",
-            "cnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdycGMudGVzdGluZy5TaW1w",
-            "bGVSZXNwb25zZTABElIKEVN0cmVhbWluZ0JvdGhXYXlzEhsuZ3JwYy50ZXN0",
-            "aW5nLlNpbXBsZVJlcXVlc3QaHC5ncnBjLnRlc3RpbmcuU2ltcGxlUmVzcG9u",
-            "c2UoATABMpcCCg1Xb3JrZXJTZXJ2aWNlEkUKCVJ1blNlcnZlchIYLmdycGMu",
-            "dGVzdGluZy5TZXJ2ZXJBcmdzGhouZ3JwYy50ZXN0aW5nLlNlcnZlclN0YXR1",
-            "cygBMAESRQoJUnVuQ2xpZW50EhguZ3JwYy50ZXN0aW5nLkNsaWVudEFyZ3Ma",
-            "Gi5ncnBjLnRlc3RpbmcuQ2xpZW50U3RhdHVzKAEwARJCCglDb3JlQ291bnQS",
-            "GS5ncnBjLnRlc3RpbmcuQ29yZVJlcXVlc3QaGi5ncnBjLnRlc3RpbmcuQ29y",
-            "ZVJlc3BvbnNlEjQKClF1aXRXb3JrZXISEi5ncnBjLnRlc3RpbmcuVm9pZBoS",
-            "LmdycGMudGVzdGluZy5Wb2lkMl4KGFJlcG9ydFFwc1NjZW5hcmlvU2Vydmlj",
-            "ZRJCCg5SZXBvcnRTY2VuYXJpbxIcLmdycGMudGVzdGluZy5TY2VuYXJpb1Jl",
-            "c3VsdBoSLmdycGMudGVzdGluZy5Wb2lkYgZwcm90bzM="));
+            "dG8aJHNyYy9wcm90by9ncnBjL3Rlc3RpbmcvY29udHJvbC5wcm90bzKmAwoQ",
+            "QmVuY2htYXJrU2VydmljZRJGCglVbmFyeUNhbGwSGy5ncnBjLnRlc3Rpbmcu",
+            "U2ltcGxlUmVxdWVzdBocLmdycGMudGVzdGluZy5TaW1wbGVSZXNwb25zZRJO",
+            "Cg1TdHJlYW1pbmdDYWxsEhsuZ3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3Qa",
+            "HC5ncnBjLnRlc3RpbmcuU2ltcGxlUmVzcG9uc2UoATABElIKE1N0cmVhbWlu",
+            "Z0Zyb21DbGllbnQSGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdy",
+            "cGMudGVzdGluZy5TaW1wbGVSZXNwb25zZSgBElIKE1N0cmVhbWluZ0Zyb21T",
+            "ZXJ2ZXISGy5ncnBjLnRlc3RpbmcuU2ltcGxlUmVxdWVzdBocLmdycGMudGVz",
+            "dGluZy5TaW1wbGVSZXNwb25zZTABElIKEVN0cmVhbWluZ0JvdGhXYXlzEhsu",
+            "Z3JwYy50ZXN0aW5nLlNpbXBsZVJlcXVlc3QaHC5ncnBjLnRlc3RpbmcuU2lt",
+            "cGxlUmVzcG9uc2UoATABMpcCCg1Xb3JrZXJTZXJ2aWNlEkUKCVJ1blNlcnZl",
+            "chIYLmdycGMudGVzdGluZy5TZXJ2ZXJBcmdzGhouZ3JwYy50ZXN0aW5nLlNl",
+            "cnZlclN0YXR1cygBMAESRQoJUnVuQ2xpZW50EhguZ3JwYy50ZXN0aW5nLkNs",
+            "aWVudEFyZ3MaGi5ncnBjLnRlc3RpbmcuQ2xpZW50U3RhdHVzKAEwARJCCglD",
+            "b3JlQ291bnQSGS5ncnBjLnRlc3RpbmcuQ29yZVJlcXVlc3QaGi5ncnBjLnRl",
+            "c3RpbmcuQ29yZVJlc3BvbnNlEjQKClF1aXRXb3JrZXISEi5ncnBjLnRlc3Rp",
+            "bmcuVm9pZBoSLmdycGMudGVzdGluZy5Wb2lkMl4KGFJlcG9ydFFwc1NjZW5h",
+            "cmlvU2VydmljZRJCCg5SZXBvcnRTY2VuYXJpbxIcLmdycGMudGVzdGluZy5T",
+            "Y2VuYXJpb1Jlc3VsdBoSLmdycGMudGVzdGluZy5Wb2lkYgZwcm90bzM="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
-          new pbr::FileDescriptor[] { global::Grpc.Testing.MessagesReflection.Descriptor, global::Grpc.Testing.ControlReflection.Descriptor, global::Grpc.Testing.StatsReflection.Descriptor, },
+          new pbr::FileDescriptor[] { global::Grpc.Testing.MessagesReflection.Descriptor, global::Grpc.Testing.ControlReflection.Descriptor, },
           new pbr::GeneratedClrTypeInfo(null, null));
     }
     #endregion
diff --git a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
index bfae4ee..d2e4f2e 100644
--- a/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/ServicesGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/services.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/services.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015 gRPC authors.
 //
diff --git a/src/csharp/Grpc.IntegrationTesting/Stats.cs b/src/csharp/Grpc.IntegrationTesting/Stats.cs
index 23b56df..e082ae7 100644
--- a/src/csharp/Grpc.IntegrationTesting/Stats.cs
+++ b/src/csharp/Grpc.IntegrationTesting/Stats.cs
@@ -23,28 +23,30 @@
       byte[] descriptorData = global::System.Convert.FromBase64String(
           string.Concat(
             "CiJzcmMvcHJvdG8vZ3JwYy90ZXN0aW5nL3N0YXRzLnByb3RvEgxncnBjLnRl",
-            "c3RpbmcikQEKC1NlcnZlclN0YXRzEhQKDHRpbWVfZWxhcHNlZBgBIAEoARIR",
-            "Cgl0aW1lX3VzZXIYAiABKAESEwoLdGltZV9zeXN0ZW0YAyABKAESFgoOdG90",
-            "YWxfY3B1X3RpbWUYBCABKAQSFQoNaWRsZV9jcHVfdGltZRgFIAEoBBIVCg1j",
-            "cV9wb2xsX2NvdW50GAYgASgEIjsKD0hpc3RvZ3JhbVBhcmFtcxISCgpyZXNv",
-            "bHV0aW9uGAEgASgBEhQKDG1heF9wb3NzaWJsZRgCIAEoASJ3Cg1IaXN0b2dy",
-            "YW1EYXRhEg4KBmJ1Y2tldBgBIAMoDRIQCghtaW5fc2VlbhgCIAEoARIQCght",
-            "YXhfc2VlbhgDIAEoARILCgNzdW0YBCABKAESFgoOc3VtX29mX3NxdWFyZXMY",
-            "BSABKAESDQoFY291bnQYBiABKAEiOAoSUmVxdWVzdFJlc3VsdENvdW50EhMK",
-            "C3N0YXR1c19jb2RlGAEgASgFEg0KBWNvdW50GAIgASgDIs0BCgtDbGllbnRT",
-            "dGF0cxIuCglsYXRlbmNpZXMYASABKAsyGy5ncnBjLnRlc3RpbmcuSGlzdG9n",
-            "cmFtRGF0YRIUCgx0aW1lX2VsYXBzZWQYAiABKAESEQoJdGltZV91c2VyGAMg",
-            "ASgBEhMKC3RpbWVfc3lzdGVtGAQgASgBEjkKD3JlcXVlc3RfcmVzdWx0cxgF",
-            "IAMoCzIgLmdycGMudGVzdGluZy5SZXF1ZXN0UmVzdWx0Q291bnQSFQoNY3Ff",
-            "cG9sbF9jb3VudBgGIAEoBGIGcHJvdG8z"));
+            "c3RpbmcaH3NyYy9wcm90by9ncnBjL2NvcmUvc3RhdHMucHJvdG8itwEKC1Nl",
+            "cnZlclN0YXRzEhQKDHRpbWVfZWxhcHNlZBgBIAEoARIRCgl0aW1lX3VzZXIY",
+            "AiABKAESEwoLdGltZV9zeXN0ZW0YAyABKAESFgoOdG90YWxfY3B1X3RpbWUY",
+            "BCABKAQSFQoNaWRsZV9jcHVfdGltZRgFIAEoBBIVCg1jcV9wb2xsX2NvdW50",
+            "GAYgASgEEiQKCmNvcmVfc3RhdHMYByABKAsyEC5ncnBjLmNvcmUuU3RhdHMi",
+            "OwoPSGlzdG9ncmFtUGFyYW1zEhIKCnJlc29sdXRpb24YASABKAESFAoMbWF4",
+            "X3Bvc3NpYmxlGAIgASgBIncKDUhpc3RvZ3JhbURhdGESDgoGYnVja2V0GAEg",
+            "AygNEhAKCG1pbl9zZWVuGAIgASgBEhAKCG1heF9zZWVuGAMgASgBEgsKA3N1",
+            "bRgEIAEoARIWCg5zdW1fb2Zfc3F1YXJlcxgFIAEoARINCgVjb3VudBgGIAEo",
+            "ASI4ChJSZXF1ZXN0UmVzdWx0Q291bnQSEwoLc3RhdHVzX2NvZGUYASABKAUS",
+            "DQoFY291bnQYAiABKAMi8wEKC0NsaWVudFN0YXRzEi4KCWxhdGVuY2llcxgB",
+            "IAEoCzIbLmdycGMudGVzdGluZy5IaXN0b2dyYW1EYXRhEhQKDHRpbWVfZWxh",
+            "cHNlZBgCIAEoARIRCgl0aW1lX3VzZXIYAyABKAESEwoLdGltZV9zeXN0ZW0Y",
+            "BCABKAESOQoPcmVxdWVzdF9yZXN1bHRzGAUgAygLMiAuZ3JwYy50ZXN0aW5n",
+            "LlJlcXVlc3RSZXN1bHRDb3VudBIVCg1jcV9wb2xsX2NvdW50GAYgASgEEiQK",
+            "CmNvcmVfc3RhdHMYByABKAsyEC5ncnBjLmNvcmUuU3RhdHNiBnByb3RvMw=="));
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
-          new pbr::FileDescriptor[] { },
+          new pbr::FileDescriptor[] { global::Grpc.Core.StatsReflection.Descriptor, },
           new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
-            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ServerStats), global::Grpc.Testing.ServerStats.Parser, new[]{ "TimeElapsed", "TimeUser", "TimeSystem", "TotalCpuTime", "IdleCpuTime", "CqPollCount" }, null, null, null),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ServerStats), global::Grpc.Testing.ServerStats.Parser, new[]{ "TimeElapsed", "TimeUser", "TimeSystem", "TotalCpuTime", "IdleCpuTime", "CqPollCount", "CoreStats" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.HistogramParams), global::Grpc.Testing.HistogramParams.Parser, new[]{ "Resolution", "MaxPossible" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.HistogramData), global::Grpc.Testing.HistogramData.Parser, new[]{ "Bucket", "MinSeen", "MaxSeen", "Sum", "SumOfSquares", "Count" }, null, null, null),
             new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.RequestResultCount), global::Grpc.Testing.RequestResultCount.Parser, new[]{ "StatusCode", "Count" }, null, null, null),
-            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ClientStats), global::Grpc.Testing.ClientStats.Parser, new[]{ "Latencies", "TimeElapsed", "TimeUser", "TimeSystem", "RequestResults", "CqPollCount" }, null, null, null)
+            new pbr::GeneratedClrTypeInfo(typeof(global::Grpc.Testing.ClientStats), global::Grpc.Testing.ClientStats.Parser, new[]{ "Latencies", "TimeElapsed", "TimeUser", "TimeSystem", "RequestResults", "CqPollCount", "CoreStats" }, null, null, null)
           }));
     }
     #endregion
@@ -81,6 +83,7 @@
       totalCpuTime_ = other.totalCpuTime_;
       idleCpuTime_ = other.idleCpuTime_;
       cqPollCount_ = other.cqPollCount_;
+      CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -173,6 +176,20 @@
       }
     }
 
+    /// <summary>Field number for the "core_stats" field.</summary>
+    public const int CoreStatsFieldNumber = 7;
+    private global::Grpc.Core.Stats coreStats_;
+    /// <summary>
+    /// Core library stats
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public global::Grpc.Core.Stats CoreStats {
+      get { return coreStats_; }
+      set {
+        coreStats_ = value;
+      }
+    }
+
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ServerStats);
@@ -192,6 +209,7 @@
       if (TotalCpuTime != other.TotalCpuTime) return false;
       if (IdleCpuTime != other.IdleCpuTime) return false;
       if (CqPollCount != other.CqPollCount) return false;
+      if (!object.Equals(CoreStats, other.CoreStats)) return false;
       return true;
     }
 
@@ -204,6 +222,7 @@
       if (TotalCpuTime != 0UL) hash ^= TotalCpuTime.GetHashCode();
       if (IdleCpuTime != 0UL) hash ^= IdleCpuTime.GetHashCode();
       if (CqPollCount != 0UL) hash ^= CqPollCount.GetHashCode();
+      if (coreStats_ != null) hash ^= CoreStats.GetHashCode();
       return hash;
     }
 
@@ -238,6 +257,10 @@
         output.WriteRawTag(48);
         output.WriteUInt64(CqPollCount);
       }
+      if (coreStats_ != null) {
+        output.WriteRawTag(58);
+        output.WriteMessage(CoreStats);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -261,6 +284,9 @@
       if (CqPollCount != 0UL) {
         size += 1 + pb::CodedOutputStream.ComputeUInt64Size(CqPollCount);
       }
+      if (coreStats_ != null) {
+        size += 1 + pb::CodedOutputStream.ComputeMessageSize(CoreStats);
+      }
       return size;
     }
 
@@ -287,6 +313,12 @@
       if (other.CqPollCount != 0UL) {
         CqPollCount = other.CqPollCount;
       }
+      if (other.coreStats_ != null) {
+        if (coreStats_ == null) {
+          coreStats_ = new global::Grpc.Core.Stats();
+        }
+        CoreStats.MergeFrom(other.CoreStats);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -321,6 +353,13 @@
             CqPollCount = input.ReadUInt64();
             break;
           }
+          case 58: {
+            if (coreStats_ == null) {
+              coreStats_ = new global::Grpc.Core.Stats();
+            }
+            input.ReadMessage(coreStats_);
+            break;
+          }
         }
       }
     }
@@ -909,6 +948,7 @@
       timeSystem_ = other.timeSystem_;
       requestResults_ = other.requestResults_.Clone();
       cqPollCount_ = other.cqPollCount_;
+      CoreStats = other.coreStats_ != null ? other.CoreStats.Clone() : null;
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -993,6 +1033,20 @@
       }
     }
 
+    /// <summary>Field number for the "core_stats" field.</summary>
+    public const int CoreStatsFieldNumber = 7;
+    private global::Grpc.Core.Stats coreStats_;
+    /// <summary>
+    /// Core library stats
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public global::Grpc.Core.Stats CoreStats {
+      get { return coreStats_; }
+      set {
+        coreStats_ = value;
+      }
+    }
+
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public override bool Equals(object other) {
       return Equals(other as ClientStats);
@@ -1012,6 +1066,7 @@
       if (TimeSystem != other.TimeSystem) return false;
       if(!requestResults_.Equals(other.requestResults_)) return false;
       if (CqPollCount != other.CqPollCount) return false;
+      if (!object.Equals(CoreStats, other.CoreStats)) return false;
       return true;
     }
 
@@ -1024,6 +1079,7 @@
       if (TimeSystem != 0D) hash ^= TimeSystem.GetHashCode();
       hash ^= requestResults_.GetHashCode();
       if (CqPollCount != 0UL) hash ^= CqPollCount.GetHashCode();
+      if (coreStats_ != null) hash ^= CoreStats.GetHashCode();
       return hash;
     }
 
@@ -1055,6 +1111,10 @@
         output.WriteRawTag(48);
         output.WriteUInt64(CqPollCount);
       }
+      if (coreStats_ != null) {
+        output.WriteRawTag(58);
+        output.WriteMessage(CoreStats);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1076,6 +1136,9 @@
       if (CqPollCount != 0UL) {
         size += 1 + pb::CodedOutputStream.ComputeUInt64Size(CqPollCount);
       }
+      if (coreStats_ != null) {
+        size += 1 + pb::CodedOutputStream.ComputeMessageSize(CoreStats);
+      }
       return size;
     }
 
@@ -1103,6 +1166,12 @@
       if (other.CqPollCount != 0UL) {
         CqPollCount = other.CqPollCount;
       }
+      if (other.coreStats_ != null) {
+        if (coreStats_ == null) {
+          coreStats_ = new global::Grpc.Core.Stats();
+        }
+        CoreStats.MergeFrom(other.CoreStats);
+      }
     }
 
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -1140,6 +1209,13 @@
             CqPollCount = input.ReadUInt64();
             break;
           }
+          case 58: {
+            if (coreStats_ == null) {
+              coreStats_ = new global::Grpc.Core.Stats();
+            }
+            input.ReadMessage(coreStats_);
+            break;
+          }
         }
       }
     }
diff --git a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
index b419dd1..c0d147c 100644
--- a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: src/proto/grpc/testing/test.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: src/proto/grpc/testing/test.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2015-2016 gRPC authors.
 //
diff --git a/src/csharp/Grpc.Reflection/Reflection.cs b/src/csharp/Grpc.Reflection/Reflection.cs
index 86e9aac..60090e5 100644
--- a/src/csharp/Grpc.Reflection/Reflection.cs
+++ b/src/csharp/Grpc.Reflection/Reflection.cs
@@ -345,7 +345,10 @@
           FileContainingSymbol = other.FileContainingSymbol;
           break;
         case MessageRequestOneofCase.FileContainingExtension:
-          FileContainingExtension = other.FileContainingExtension;
+          if (FileContainingExtension == null) {
+            FileContainingExtension = new global::Grpc.Reflection.V1Alpha.ExtensionRequest();
+          }
+          FileContainingExtension.MergeFrom(other.FileContainingExtension);
           break;
         case MessageRequestOneofCase.AllExtensionNumbersOfType:
           AllExtensionNumbersOfType = other.AllExtensionNumbersOfType;
@@ -816,16 +819,28 @@
       }
       switch (other.MessageResponseCase) {
         case MessageResponseOneofCase.FileDescriptorResponse:
-          FileDescriptorResponse = other.FileDescriptorResponse;
+          if (FileDescriptorResponse == null) {
+            FileDescriptorResponse = new global::Grpc.Reflection.V1Alpha.FileDescriptorResponse();
+          }
+          FileDescriptorResponse.MergeFrom(other.FileDescriptorResponse);
           break;
         case MessageResponseOneofCase.AllExtensionNumbersResponse:
-          AllExtensionNumbersResponse = other.AllExtensionNumbersResponse;
+          if (AllExtensionNumbersResponse == null) {
+            AllExtensionNumbersResponse = new global::Grpc.Reflection.V1Alpha.ExtensionNumberResponse();
+          }
+          AllExtensionNumbersResponse.MergeFrom(other.AllExtensionNumbersResponse);
           break;
         case MessageResponseOneofCase.ListServicesResponse:
-          ListServicesResponse = other.ListServicesResponse;
+          if (ListServicesResponse == null) {
+            ListServicesResponse = new global::Grpc.Reflection.V1Alpha.ListServiceResponse();
+          }
+          ListServicesResponse.MergeFrom(other.ListServicesResponse);
           break;
         case MessageResponseOneofCase.ErrorResponse:
-          ErrorResponse = other.ErrorResponse;
+          if (ErrorResponse == null) {
+            ErrorResponse = new global::Grpc.Reflection.V1Alpha.ErrorResponse();
+          }
+          ErrorResponse.MergeFrom(other.ErrorResponse);
           break;
       }
 
diff --git a/src/csharp/Grpc.Reflection/ReflectionGrpc.cs b/src/csharp/Grpc.Reflection/ReflectionGrpc.cs
index 5843957..0195186 100644
--- a/src/csharp/Grpc.Reflection/ReflectionGrpc.cs
+++ b/src/csharp/Grpc.Reflection/ReflectionGrpc.cs
@@ -1,5 +1,7 @@
-// Generated by the protocol buffer compiler.  DO NOT EDIT!
-// source: grpc/reflection/v1alpha/reflection.proto
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: grpc/reflection/v1alpha/reflection.proto
+// </auto-generated>
 // Original file comments:
 // Copyright 2016 gRPC authors.
 //