interpreting server_mode field (to support Valkey 8+ cluster) (#3050)

* interpreting server_mode field (to support Valkey 8+ cluster)

* add valkey server_mode unit test

* release notes

---------

Co-authored-by: mgravell <marc.gravell@gmail.com>

Author: wipiano

docs/ReleaseNotes.md

@@ -8,7 +8,7 @@ Current package versions:
 
 ## Unreleased
 
-- (none)
+- Detect server-mode correctly on Valkey 8+ instances ([#3050 by @wipiano](https://github.com/StackExchange/StackExchange.Redis/pull/3050))
 
 ## 2.12.14
 

src/StackExchange.Redis/AutoConfigureInfoField.cs

@@ -37,6 +37,9 @@ internal enum AutoConfigureInfoField
 
     [AsciiHash("valkey_version")]
     ValkeyVersion,
+
+    [AsciiHash("server_mode")]
+    ServerMode,
 }
 
 /// <summary>

src/StackExchange.Redis/ResultProcessor.cs

@@ -920,6 +920,7 @@ protected override bool SetResultCore(PhysicalConnection connection, Message mes
                                             }
                                             break;
                                         case AutoConfigureInfoField.RedisMode:
+                                        case AutoConfigureInfoField.ServerMode:
                                             if (ServerTypeMetadata.TryParse(valSpan, out var serverType))
                                             {
                                                 server.ServerType = serverType;

src/StackExchange.Redis/VectorSetAddMessage.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Threading;
 
 namespace StackExchange.Redis;
 

tests/StackExchange.Redis.Tests/AutoConfigureInfoFieldUnitTests.cs

@@ -14,6 +14,7 @@ public class AutoConfigureInfoFieldUnitTests
     [InlineData("run_id", (int)AutoConfigureInfoField.RunId)]
     [InlineData("garnet_version", (int)AutoConfigureInfoField.GarnetVersion)]
     [InlineData("valkey_version", (int)AutoConfigureInfoField.ValkeyVersion)]
+    [InlineData("server_mode", (int)AutoConfigureInfoField.ServerMode)]
     public void TryParse_CharSpan_KnownFields(string value, int expected)
     {
         Assert.True(AutoConfigureInfoFieldMetadata.TryParse(value.AsSpan(), out var actual));

tests/StackExchange.Redis.Tests/ValkeyUnitTests.cs

@@ -0,0 +1,37 @@
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace StackExchange.Redis.Tests;
+
+public class ValkeyUnitTests(ITestOutputHelper log)
+{
+    [Theory]
+    [InlineData(ServerType.Standalone)]
+    [InlineData(ServerType.Cluster)]
+    public async Task IdentifyValkeyCluster(ServerType type)
+    {
+        using InProcessValkeyLikeServer server = new(log) { ServerType = type };
+        await using var client = await server.ConnectAsync();
+        var serverApi = client.GetServer(server.DefaultEndPoint);
+        Assert.Equal(type, serverApi.ServerType);
+        Assert.Equal(ProductVariant.Valkey, serverApi.GetProductVariant(out var version));
+        Assert.Equal("8.1",  version);
+    }
+
+    private sealed class InProcessValkeyLikeServer(ITestOutputHelper log) : InProcessTestServer(log)
+    {
+        // see https://github.com/StackExchange/StackExchange.Redis/pull/3050
+        protected override string ServerModeKey => "server_mode";
+
+        protected override void Info(StringBuilder sb, string section)
+        {
+            base.Info(sb, section);
+            if (section is "Server")
+            {
+                sb.AppendLine("valkey_version:8.1")
+                    .AppendLine("server_name:valkey");
+            }
+        }
+    }
+}

toys/StackExchange.Redis.Server/RedisServer.cs

@@ -275,7 +275,7 @@ protected virtual TypedRedisValue Hello(RedisClient client, in RedisRequest requ
             span[6] = TypedRedisValue.BulkString("id");
             span[7] = TypedRedisValue.Integer(client.Id);
             span[8] = TypedRedisValue.BulkString("mode");
-            span[9] = TypedRedisValue.BulkString(ModeString);
+            span[9] = TypedRedisValue.BulkString(ServerModeValue);
             span[10] = TypedRedisValue.BulkString("role");
             span[11] = TypedRedisValue.BulkString("master");
             span[12] = TypedRedisValue.BulkString("modules");
@@ -1138,12 +1138,15 @@ public Version RedisVersion
         public DateTime StartTime { get; set; } = DateTime.UtcNow;
         public ServerType ServerType { get; set; } = ServerType.Standalone;
 
-        private string ModeString => ServerType switch
+        private string ServerModeValue => ServerType switch
         {
             ServerType.Cluster => "cluster",
             ServerType.Sentinel => "sentinel",
             _ => "standalone",
         };
+
+        protected virtual string ServerModeKey => "redis_mode";
+
         protected virtual void Info(StringBuilder sb, string section)
         {
             StringBuilder AddHeader()
@@ -1156,7 +1159,7 @@ StringBuilder AddHeader()
             {
                 case "Server":
                     AddHeader().Append("redis_version:").AppendLine(VersionString)
-                        .Append("redis_mode:").Append(ModeString).AppendLine()
+                        .Append(ServerModeKey).Append(':').Append(ServerModeValue).AppendLine()
                         .Append("os:").Append(Environment.OSVersion).AppendLine()
                         .Append("arch_bits:x").Append(IntPtr.Size * 8).AppendLine();
                     using (var process = Process.GetCurrentProcess())