[automatic failover] Replace EchoStrategy with PingStrategy (#4313)

* - replace EchoStrategy with PingStrategy

* - fix doc

Author: atakavci

.github/wordlist.txt

@@ -23,7 +23,6 @@ CRDB
 Dockerfile
 EVAL
 EVALSHA
-EchoStrategy
 FTCreateParams
 FTSearchParams
 Failback
@@ -71,6 +70,7 @@ OpenCensus
 OpenTelemetry
 OpenTracing
 Otel
+PingStrategy
 POJO
 POJOs
 PoolConfig

docs/failover.md

@@ -159,18 +159,18 @@ The health check system operates independently of your application traffic, runn
 
 #### Available Health Check Types
 
-##### 1. EchoStrategy (Default)
+##### 1. PingStrategy (Default)
 
-The `EchoStrategy` is the default health check implementation that uses Redis's `ECHO` command to verify both connectivity and write capability.
+The `PingStrategy` is the default health check implementation that uses Redis's `PING` command to verify both connectivity and write capability.
 
 **Use Cases:**
 - General-purpose health checking for most Redis deployments
 - Verifying both read and write operations
 - Simple connectivity validation
 
 **How it works:**
-- Sends `ECHO "HealthCheck"` command to the Redis server
-- Expects exact response `"HealthCheck"` to consider the server healthy
+- Sends `PING` command to the Redis server
+- Expects exact response `"PONG"` to consider the server healthy
 - Any exception or unexpected response marks the server as unhealthy
 
 ##### 2. LagAwareStrategy [PREVIEW] (Redis Enterprise)

src/main/java/redis/clients/jedis/MultiDbConfig.java

@@ -11,7 +11,7 @@
 import redis.clients.jedis.exceptions.JedisConnectionException;
 import redis.clients.jedis.exceptions.JedisValidationException;
 import redis.clients.jedis.mcf.ConnectionFailoverException;
-import redis.clients.jedis.mcf.EchoStrategy;
+import redis.clients.jedis.mcf.PingStrategy;
 import redis.clients.jedis.mcf.HealthCheckStrategy;
 
 /**
@@ -71,7 +71,7 @@
  * </p>
  * @see redis.clients.jedis.mcf.MultiDbConnectionProvider
  * @see redis.clients.jedis.mcf.HealthCheckStrategy
- * @see redis.clients.jedis.mcf.EchoStrategy
+ * @see redis.clients.jedis.mcf.PingStrategy
  * @see redis.clients.jedis.mcf.LagAwareStrategy
  * @since 7.0
  */
@@ -90,13 +90,13 @@ public final class MultiDbConfig {
    * <strong>Common Implementations:</strong>
    * </p>
    * <ul>
-   * <li>{@link redis.clients.jedis.mcf.EchoStrategy#DEFAULT} - Uses Redis ECHO command for health
+   * <li>{@link redis.clients.jedis.mcf.PingStrategy#DEFAULT} - Uses Redis PING command for health
    * checks</li>
    * <li>Custom implementations for specific monitoring requirements</li>
    * <li>Redis Enterprise implementations using REST API monitoring</li>
    * </ul>
    * @see redis.clients.jedis.mcf.HealthCheckStrategy
-   * @see redis.clients.jedis.mcf.EchoStrategy
+   * @see redis.clients.jedis.mcf.PingStrategy
    * @see redis.clients.jedis.mcf.LagAwareStrategy
    */
   public static interface StrategySupplier {
@@ -839,15 +839,15 @@ public static class DatabaseConfig {
 
     /**
      * Strategy supplier for creating health check instances for this database. Default is
-     * EchoStrategy.DEFAULT.
+     * PingStrategy.DEFAULT.
      */
     private StrategySupplier healthCheckStrategySupplier;
 
     /**
      * Constructs a DatabaseConfig with basic endpoint and client configuration.
      * <p>
      * This constructor creates a database configuration with default settings: weight of 1.0f and
-     * EchoStrategy for health checks. Use the {@link Builder} for more advanced configuration
+     * PingStrategy for health checks. Use the {@link Builder} for more advanced configuration
      * options.
      * </p>
      * @param endpoint the Redis endpoint (host and port)
@@ -863,7 +863,7 @@ public DatabaseConfig(Endpoint endpoint, JedisClientConfig clientConfig) {
      * Constructs a DatabaseConfig with endpoint, client, and connection pool configuration.
      * <p>
      * This constructor allows specification of connection pool settings in addition to basic
-     * endpoint configuration. Default weight of 1.0f and EchoStrategy for health checks are used.
+     * endpoint configuration. Default weight of 1.0f and PingStrategy for health checks are used.
      * </p>
      * @param endpoint the Redis endpoint (host and port)
      * @param clientConfig the Jedis client configuration
@@ -963,7 +963,7 @@ public StrategySupplier getHealthCheckStrategySupplier() {
      * </p>
      * <ul>
      * <li><strong>Weight:</strong> 1.0f (standard priority)</li>
-     * <li><strong>Health Check:</strong> {@link redis.clients.jedis.mcf.EchoStrategy#DEFAULT}</li>
+     * <li><strong>Health Check:</strong> {@link redis.clients.jedis.mcf.PingStrategy#DEFAULT}</li>
      * <li><strong>Connection Pool:</strong> null (uses default pooling)</li>
      * </ul>
      */
@@ -980,8 +980,8 @@ public static class Builder {
       /** Weight for database selection priority. Default: 1.0f */
       private float weight = 1.0f;
 
-      /** Health check strategy supplier. Default: EchoStrategy.DEFAULT */
-      private StrategySupplier healthCheckStrategySupplier = EchoStrategy.DEFAULT;
+      /** Health check strategy supplier. Default: PingStrategy.DEFAULT */
+      private StrategySupplier healthCheckStrategySupplier = PingStrategy.DEFAULT;
 
       /**
        * Constructs a new Builder with required endpoint and client configuration.
@@ -1089,7 +1089,7 @@ public Builder healthCheckStrategy(HealthCheckStrategy healthCheckStrategy) {
        * </ul>
        * <p>
        * When health checks are enabled (true) and no strategy supplier was previously set, the
-       * default {@link redis.clients.jedis.mcf.EchoStrategy#DEFAULT} will be used.
+       * default {@link redis.clients.jedis.mcf.PingStrategy#DEFAULT} will be used.
        * </p>
        * @param healthCheckEnabled true to enable health checks, false to disable
        * @return this builder instance for method chaining
@@ -1098,7 +1098,7 @@ public Builder healthCheckEnabled(boolean healthCheckEnabled) {
         if (!healthCheckEnabled) {
           this.healthCheckStrategySupplier = null;
         } else if (healthCheckStrategySupplier == null) {
-          this.healthCheckStrategySupplier = EchoStrategy.DEFAULT;
+          this.healthCheckStrategySupplier = PingStrategy.DEFAULT;
         }
         return this;
       }

src/main/java/redis/clients/jedis/mcf/EchoStrategy.java renamed to src/main/java/redis/clients/jedis/mcf/PingStrategy.java

@@ -10,17 +10,17 @@
 import redis.clients.jedis.UnifiedJedis;
 import redis.clients.jedis.MultiDbConfig.StrategySupplier;
 
-public class EchoStrategy implements HealthCheckStrategy {
+public class PingStrategy implements HealthCheckStrategy {
   private static final int MAX_HEALTH_CHECK_POOL_SIZE = 2;
 
   private final UnifiedJedis jedis;
   private final HealthCheckStrategy.Config config;
 
-  public EchoStrategy(HostAndPort hostAndPort, JedisClientConfig jedisClientConfig) {
+  public PingStrategy(HostAndPort hostAndPort, JedisClientConfig jedisClientConfig) {
     this(hostAndPort, jedisClientConfig, HealthCheckStrategy.Config.create());
   }
 
-  public EchoStrategy(HostAndPort hostAndPort, JedisClientConfig jedisClientConfig,
+  public PingStrategy(HostAndPort hostAndPort, JedisClientConfig jedisClientConfig,
       HealthCheckStrategy.Config config) {
     GenericObjectPoolConfig<Connection> poolConfig = new GenericObjectPoolConfig<>();
     poolConfig.setMaxTotal(MAX_HEALTH_CHECK_POOL_SIZE);
@@ -55,15 +55,14 @@ public int getDelayInBetweenProbes() {
 
   @Override
   public HealthStatus doHealthCheck(Endpoint endpoint) {
-    return "HealthCheck".equals(jedis.echo("HealthCheck")) ? HealthStatus.HEALTHY
-        : HealthStatus.UNHEALTHY;
+    return "PONG".equals(jedis.ping()) ? HealthStatus.HEALTHY : HealthStatus.UNHEALTHY;
   }
 
   @Override
   public void close() {
     jedis.close();
   }
 
-  public static final StrategySupplier DEFAULT = EchoStrategy::new;
+  public static final StrategySupplier DEFAULT = PingStrategy::new;
 
 }

src/test/java/redis/clients/jedis/mcf/DefaultValuesTest.java

@@ -33,8 +33,8 @@ void testDefaultValuesInConfig() {
     // check healthchecks enabled
     assertNotNull(databaseConfig.getHealthCheckStrategySupplier());
 
-    // check default healthcheck strategy is echo
-    assertEquals(EchoStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
+    // check default healthcheck strategy is PingStrategy
+    assertEquals(PingStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
 
     // check number of probes
     assertEquals(3,

src/test/java/redis/clients/jedis/mcf/HealthCheckIntegrationTest.java

@@ -42,9 +42,9 @@ public void testDisableHealthCheck() {
 
   @Test
   public void testDefaultStrategySupplier() {
-    // Create a default strategy supplier that creates EchoStrategy instances
+    // Create a default strategy supplier that creates PingStrategy instances
     MultiDbConfig.StrategySupplier defaultSupplier = (hostAndPort, jedisClientConfig) -> {
-      return new EchoStrategy(hostAndPort, jedisClientConfig);
+      return new PingStrategy(hostAndPort, jedisClientConfig);
     };
     MultiDbConnectionProvider customProvider = getMCCF(defaultSupplier);
     try (UnifiedJedis customClient = new UnifiedJedis(customProvider)) {
@@ -113,8 +113,8 @@ public void testProbingLogic_RealHealthCheckWithProbes() throws InterruptedExcep
         }
         // Third attempt succeeds - do actual health check
         try (UnifiedJedis jedis = new UnifiedJedis(hostAndPort, jedisClientConfig)) {
-          String result = jedis.echo("HealthCheck");
-          return "HealthCheck".equals(result) ? HealthStatus.HEALTHY : HealthStatus.UNHEALTHY;
+          String result = jedis.ping();
+          return "PONG".equals(result) ? HealthStatus.HEALTHY : HealthStatus.UNHEALTHY;
         } catch (Exception e) {
           return HealthStatus.UNHEALTHY;
         }

src/test/java/redis/clients/jedis/mcf/HealthCheckTest.java

@@ -321,11 +321,11 @@ void testHealthStatusManagerClose() {
     verify(closeableStrategy).close();
   }
 
-  // ========== EchoStrategy Tests ==========
+  // ========== PingStrategy Tests ==========
 
   @Test
-  void testEchoStrategyCustomIntervalTimeout() {
-    try (EchoStrategy strategy = new EchoStrategy(testEndpoint, testConfig,
+  void testPingStrategyCustomIntervalTimeout() {
+    try (PingStrategy strategy = new PingStrategy(testEndpoint, testConfig,
         HealthCheckStrategy.Config.builder().interval(2000).timeout(1500).delayInBetweenProbes(50)
             .numProbes(11).policy(BuiltIn.ANY_SUCCESS).build())) {
       assertEquals(2000, strategy.getInterval());
@@ -337,11 +337,11 @@ void testEchoStrategyCustomIntervalTimeout() {
   }
 
   @Test
-  void testEchoStrategyDefaultSupplier() {
-    MultiDbConfig.StrategySupplier supplier = EchoStrategy.DEFAULT;
+  void testPingStrategyDefaultSupplier() {
+    MultiDbConfig.StrategySupplier supplier = PingStrategy.DEFAULT;
     HealthCheckStrategy strategy = supplier.get(testEndpoint, testConfig);
 
-    assertInstanceOf(EchoStrategy.class, strategy);
+    assertInstanceOf(PingStrategy.class, strategy);
   }
 
   // ========== Failover configuration Tests ==========
@@ -368,7 +368,7 @@ void testDefaultValues() {
         .builder(testEndpoint, testConfig).build();
 
     assertEquals(1.0f, databaseConfig.getWeight()); // Default weight
-    assertEquals(EchoStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier()); // Default
+    assertEquals(PingStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier()); // Default
                                                                                          // is null
                                                                                          // (no
                                                                                          // health
@@ -410,26 +410,26 @@ void testDatabaseConfigWithStrategySupplier() {
   }
 
   @Test
-  void testDatabaseConfigWithEchoStrategy() {
-    MultiDbConfig.StrategySupplier echoSupplier = (hostAndPort, jedisClientConfig) -> {
-      return new EchoStrategy(hostAndPort, jedisClientConfig);
+  void testDatabaseConfigWithPingStrategy() {
+    MultiDbConfig.StrategySupplier pingSupplier = (hostAndPort, jedisClientConfig) -> {
+      return new PingStrategy(hostAndPort, jedisClientConfig);
     };
 
     MultiDbConfig.DatabaseConfig databaseConfig = MultiDbConfig.DatabaseConfig
-        .builder(testEndpoint, testConfig).healthCheckStrategySupplier(echoSupplier).build();
+        .builder(testEndpoint, testConfig).healthCheckStrategySupplier(pingSupplier).build();
 
     MultiDbConfig.StrategySupplier supplier = databaseConfig.getHealthCheckStrategySupplier();
     assertNotNull(supplier);
-    assertInstanceOf(EchoStrategy.class, supplier.get(testEndpoint, testConfig));
+    assertInstanceOf(PingStrategy.class, supplier.get(testEndpoint, testConfig));
   }
 
   @Test
   void testDatabaseConfigWithDefaultHealthCheck() {
     MultiDbConfig.DatabaseConfig databaseConfig = MultiDbConfig.DatabaseConfig
-        .builder(testEndpoint, testConfig).build(); // Should use default EchoStrategy
+        .builder(testEndpoint, testConfig).build(); // Should use default PingStrategy
 
     assertNotNull(databaseConfig.getHealthCheckStrategySupplier());
-    assertEquals(EchoStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
+    assertEquals(PingStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
   }
 
   @Test
@@ -446,7 +446,7 @@ void testDatabaseConfigHealthCheckEnabledExplicitly() {
         .builder(testEndpoint, testConfig).healthCheckEnabled(true).build();
 
     assertNotNull(databaseConfig.getHealthCheckStrategySupplier());
-    assertEquals(EchoStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
+    assertEquals(PingStrategy.DEFAULT, databaseConfig.getHealthCheckStrategySupplier());
   }
 
   // ========== Integration Tests ==========
@@ -516,10 +516,10 @@ void testStrategySupplierPolymorphism() {
     // Test that the polymorphic design works correctly
     MultiDbConfig.StrategySupplier supplier = (hostAndPort, jedisClientConfig) -> {
       if (jedisClientConfig != null) {
-        return new EchoStrategy(hostAndPort, jedisClientConfig,
+        return new PingStrategy(hostAndPort, jedisClientConfig,
             HealthCheckStrategy.Config.builder().interval(500).timeout(250).numProbes(1).build());
       } else {
-        return new EchoStrategy(hostAndPort, DefaultJedisClientConfig.builder().build());
+        return new PingStrategy(hostAndPort, DefaultJedisClientConfig.builder().build());
       }
     };
 

src/test/java/redis/clients/jedis/mcf/MultiDbConnectionProviderInitializationTest.java

@@ -56,7 +56,7 @@ void testInitializationWithMixedHealthCheckConfiguration() {
           .build();
 
       DatabaseConfig db2 = DatabaseConfig.builder(endpoint2, clientConfig).weight(2.0f)
-          .healthCheckStrategySupplier(EchoStrategy.DEFAULT) // With
+          .healthCheckStrategySupplier(PingStrategy.DEFAULT) // With
                                                              // health
                                                              // check
           .build();

src/test/java/redis/clients/jedis/mcf/EchoStrategyIntegrationTest.java renamed to src/test/java/redis/clients/jedis/mcf/PingStrategyIntegrationTest.java

@@ -20,7 +20,7 @@
 import static org.junit.jupiter.api.Assertions.*;
 
 @Tag("failover")
-public class EchoStrategyIntegrationTest {
+public class PingStrategyIntegrationTest {
 
   private static final EndpointConfig endpoint = HostAndPorts.getRedisEndpoint("redis-failover-1");
   private static final HostAndPort proxyHostAndPort = endpoint.getHostAndPort();
@@ -55,10 +55,10 @@ public void resetProxy() throws IOException {
   }
 
   @Test
-  public void testEchoStrategyRecoversAfterDisconnect() throws Exception {
+  public void testPingStrategyRecoversAfterDisconnect() throws Exception {
     JedisClientConfig config = DefaultJedisClientConfig.builder().socketTimeoutMillis(1000)
         .connectionTimeoutMillis(1000).build();
-    try (EchoStrategy strategy = new EchoStrategy(proxyHostAndPort, config,
+    try (PingStrategy strategy = new PingStrategy(proxyHostAndPort, config,
         HealthCheckStrategy.Config.create())) {
 
       // Initial health check should work
@@ -81,11 +81,11 @@ public void testEchoStrategyRecoversAfterDisconnect() throws Exception {
   }
 
   @Test
-  public void testEchoStrategyWithConnectionTimeout() throws Exception {
+  public void testPingStrategyWithConnectionTimeout() throws Exception {
     JedisClientConfig config = DefaultJedisClientConfig.builder().socketTimeoutMillis(100)
         .connectionTimeoutMillis(100).build();
 
-    try (EchoStrategy strategy = new EchoStrategy(proxyHostAndPort, config,
+    try (PingStrategy strategy = new PingStrategy(proxyHostAndPort, config,
         HealthCheckStrategy.Config.builder().interval(1000).timeout(500).numProbes(1).build())) {
 
       // Initial health check should work
@@ -110,7 +110,7 @@ public void testEchoStrategyWithConnectionTimeout() throws Exception {
   @Test
   public void testConnectionDropDuringHealthCheck() throws Exception {
     JedisClientConfig config = DefaultJedisClientConfig.builder().socketTimeoutMillis(2000).build();
-    try (EchoStrategy strategy = new EchoStrategy(proxyHostAndPort, config,
+    try (PingStrategy strategy = new PingStrategy(proxyHostAndPort, config,
         HealthCheckStrategy.Config.create())) {
 
       // Initial health check