Enable TCP NoDelay by default #1462

Enabling NoDelay by default to avoid delayed TCP ACK's. Lettuce's flushing behavior is already optimized and the server is expected to respond without waiting for more data.
redis · Oct 16, 2020 · deca4c7 · deca4c7
1 parent d3d5054
commit deca4c7
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/src/main/java/io/lettuce/core/SocketOptions.java b/src/main/java/io/lettuce/core/SocketOptions.java
@@ -36,7 +36,7 @@ public class SocketOptions {
 
     public static final boolean DEFAULT_SO_KEEPALIVE = false;
 
-    public static final boolean DEFAULT_SO_NO_DELAY = false;
+    public static final boolean DEFAULT_SO_NO_DELAY = true;
 
     private final Duration connectTimeout;
 
@@ -148,10 +148,13 @@ public Builder keepAlive(boolean keepAlive) {
         }
 
         /**
-         * Sets whether to disable Nagle's algorithm. Defaults to {@code false} (Nagle enabled). See
+         * Sets whether to disable/enable Nagle's algorithm. Defaults to {@code true} (Nagle disabled). See
          * {@link #DEFAULT_SO_NO_DELAY}.
+         * <p>
+         * Disabling TCP NoDelay delays TCP {@code ACK} packets to await more data input before confirming the packet.
          *
-         * @param tcpNoDelay {@code true} to disable Nagle's algorithm, {@code false} to enable Nagle's algorithm.
+         * @param tcpNoDelay {@code false} to disable TCP NoDelay (enable Nagle's algorithm), {@code true} to enable TCP NoDelay
+         *        (disable Nagle's algorithm).
          * @return {@code this}
          * @see java.net.SocketOptions#TCP_NODELAY
          */

diff --git a/src/test/java/io/lettuce/core/SocketOptionsUnitTests.java b/src/test/java/io/lettuce/core/SocketOptionsUnitTests.java
@@ -37,11 +37,11 @@ void testNew() {
     @Test
     void testBuilder() {
 
-        SocketOptions sut = SocketOptions.builder().connectTimeout(1, TimeUnit.MINUTES).keepAlive(true).tcpNoDelay(true)
+        SocketOptions sut = SocketOptions.builder().connectTimeout(1, TimeUnit.MINUTES).keepAlive(true).tcpNoDelay(false)
                 .build();
 
         assertThat(sut.isKeepAlive()).isTrue();
-        assertThat(sut.isTcpNoDelay()).isTrue();
+        assertThat(sut.isTcpNoDelay()).isFalse();
         assertThat(sut.getConnectTimeout()).isEqualTo(Duration.ofMinutes(1));
     }
 
@@ -67,7 +67,7 @@ void testCopy() {
 
     void checkAssertions(SocketOptions sut) {
         assertThat(sut.isKeepAlive()).isFalse();
-        assertThat(sut.isTcpNoDelay()).isFalse();
+        assertThat(sut.isTcpNoDelay()).isTrue();
         assertThat(sut.getConnectTimeout()).isEqualTo(Duration.ofSeconds(10));
     }
 }