Send the CLIENT SETINFO command in a fire-and-forget way

src/main/java/io/lettuce/core/RedisHandshake.java

@@ -38,6 +38,8 @@
 import io.lettuce.core.protocol.ConnectionInitializer;
 import io.lettuce.core.protocol.ProtocolVersion;
 import io.netty.channel.Channel;
+import io.netty.util.internal.logging.InternalLogger;
+import io.netty.util.internal.logging.InternalLoggerFactory;
 
 /**
  * Redis RESP2/RESP3 handshake using the configured {@link ProtocolVersion} and other options for connection initialization and
@@ -49,7 +51,7 @@
  */
 class RedisHandshake implements ConnectionInitializer {
 
-    private static final RedisVersion CLIENT_SET_INFO_SINCE = RedisVersion.of("7.2");
+    private static final InternalLogger LOG = InternalLoggerFactory.getInstance(RedisHandshake.class);
 
     private final RedisCommandBuilder<String, String> commandBuilder = new RedisCommandBuilder<>(StringCodec.UTF8);
 
@@ -99,8 +101,21 @@ public CompletionStage<Void> initialize(Channel channel) {
                     new RedisConnectionException("Protocol version" + this.requestedProtocolVersion + " not supported"));
         }
 
-        return handshake.thenCompose(
-                ignore -> applyPostHandshake(channel, connectionState.getRedisVersion(), getNegotiatedProtocolVersion()));
+        // post-handshake commands, whose execution failures would cause the connection to be considered
+        // unsuccessfully established
+        CompletableFuture<Void> postHandshake = applyPostHandshake(channel);
+
+        // post-handshake commands, executed in a 'fire and forget' manner, to avoid having to react to different
+        // implementations or versions of the server runtime, and whose execution result (whether a success or a
+        // failure ) should not alter the outcome of the connection attempt
+        CompletableFuture<Void> connectionMetadata = applyConnectionMetadata(channel).handle((result, error) -> {
+            if (error != null) {
+                LOG.debug("Error applying connection metadata", error);
+            }
+            return null;
+        });
+
+        return handshake.thenCompose(ignore -> postHandshake).thenCompose(ignore -> connectionMetadata);
     }
 
     private CompletionStage<?> tryHandshakeResp3(Channel channel) {
@@ -237,41 +252,44 @@ private AsyncCommand<String, String, Map<String, Object>> dispatchHello(Channel
         return dispatch(channel, this.commandBuilder.hello(3, null, null, connectionState.getClientName()));
     }
 
-    private CompletableFuture<Void> applyPostHandshake(Channel channel, String redisVersion,
-            ProtocolVersion negotiatedProtocolVersion) {
+    private CompletableFuture<Void> applyPostHandshake(Channel channel) {
 
         List<AsyncCommand<?, ?, ?>> postHandshake = new ArrayList<>();
 
-        ConnectionMetadata metadata = connectionState.getConnectionMetadata();
+        if (connectionState.getDb() > 0) {
+            postHandshake.add(new AsyncCommand<>(this.commandBuilder.select(connectionState.getDb())));
+        }
 
-        if (metadata.getClientName() != null && negotiatedProtocolVersion == ProtocolVersion.RESP2) {
-            postHandshake.add(new AsyncCommand<>(this.commandBuilder.clientSetname(connectionState.getClientName())));
+        if (connectionState.isReadOnly()) {
+            postHandshake.add(new AsyncCommand<>(this.commandBuilder.readOnly()));
         }
 
-        if (negotiatedProtocolVersion == ProtocolVersion.RESP3) {
+        if (postHandshake.isEmpty()) {
+            return CompletableFuture.completedFuture(null);
+        }
 
-            RedisVersion currentVersion = RedisVersion.of(redisVersion);
+        return dispatch(channel, postHandshake);
+    }
 
-            if (currentVersion.isGreaterThanOrEqualTo(CLIENT_SET_INFO_SINCE)) {
+    private CompletableFuture<Void> applyConnectionMetadata(Channel channel) {
 
-                if (LettuceStrings.isNotEmpty(metadata.getLibraryName())) {
-                    postHandshake
-                            .add(new AsyncCommand<>(this.commandBuilder.clientSetinfo("lib-name", metadata.getLibraryName())));
-                }
+        List<AsyncCommand<?, ?, ?>> postHandshake = new ArrayList<>();
 
-                if (LettuceStrings.isNotEmpty(metadata.getLibraryVersion())) {
-                    postHandshake.add(
-                            new AsyncCommand<>(this.commandBuilder.clientSetinfo("lib-ver", metadata.getLibraryVersion())));
-                }
-            }
+        ConnectionMetadata metadata = connectionState.getConnectionMetadata();
+        ProtocolVersion negotiatedProtocolVersion = getNegotiatedProtocolVersion();
+
+        if (metadata.getClientName() != null && negotiatedProtocolVersion == ProtocolVersion.RESP2) {
+            postHandshake.add(new AsyncCommand<>(this.commandBuilder.clientSetname(connectionState.getClientName())));
         }
 
-        if (connectionState.getDb() > 0) {
-            postHandshake.add(new AsyncCommand<>(this.commandBuilder.select(connectionState.getDb())));
+        if (LettuceStrings.isNotEmpty(metadata.getLibraryName())) {
+            postHandshake.add(
+                    new AsyncCommand<>(this.commandBuilder.clientSetinfo("lib-name", metadata.getLibraryName())));
         }
 
-        if (connectionState.isReadOnly()) {
-            postHandshake.add(new AsyncCommand<>(this.commandBuilder.readOnly()));
+        if (LettuceStrings.isNotEmpty(metadata.getLibraryVersion())) {
+            postHandshake.add(
+                    new AsyncCommand<>(this.commandBuilder.clientSetinfo("lib-ver", metadata.getLibraryVersion())));
         }
 
         if (postHandshake.isEmpty()) {

src/test/java/io/lettuce/core/RedisHandshakeUnitTests.java

@@ -3,7 +3,9 @@
 import static org.assertj.core.api.Assertions.*;
 
 import java.nio.ByteBuffer;
+import java.util.List;
 import java.util.Map;
+import java.util.concurrent.CompletionStage;
 
 import org.junit.jupiter.api.Test;
 
@@ -19,6 +21,8 @@
  */
 class RedisHandshakeUnitTests {
 
+    public static final String ERR_UNKNOWN_COMMAND = "ERR unknown command 'CLIENT', with args beginning with: 'SETINFO' 'lib-name' 'Lettuce'";
+
     @Test
     void handshakeWithResp3ShouldPass() {
 
@@ -71,6 +75,34 @@ void handshakeWithDiscoveryShouldDowngrade() {
         assertThat(state.getNegotiatedProtocolVersion()).isEqualTo(ProtocolVersion.RESP2);
     }
 
+    @Test
+    void handshakeFireAndForgetPostHandshake() {
+
+        EmbeddedChannel channel = new EmbeddedChannel(true, false);
+
+        ConnectionMetadata connectionMetdata = new ConnectionMetadata();
+        connectionMetdata.setLibraryName("library-name");
+        connectionMetdata.setLibraryVersion("library-version");
+
+        ConnectionState state = new ConnectionState();
+        state.setCredentialsProvider(new StaticCredentialsProvider(null, null));
+        state.apply(connectionMetdata);
+        RedisHandshake handshake = new RedisHandshake(null, false, state);
+        CompletionStage<Void> handshakeInit = handshake.initialize(channel);
+
+        AsyncCommand<String, String, Map<String, String>> hello = channel.readOutbound();
+        helloResponse(hello.getOutput());
+        hello.complete();
+
+        List<AsyncCommand<String, String, Map<String, String>>> postHandshake = channel.readOutbound();
+        postHandshake.get(0).getOutput().setError(ERR_UNKNOWN_COMMAND);
+        postHandshake.get(0).completeExceptionally(new RedisException(ERR_UNKNOWN_COMMAND));
+        postHandshake.get(0).complete();
+
+        assertThat(postHandshake.size()).isEqualTo(2);
+        assertThat(handshakeInit.toCompletableFuture().isCompletedExceptionally()).isFalse();
+    }
+
     @Test
     void shouldParseVersionWithCharacters() {