Add an option to ignore cluster init error (#3455)

src/main/java/redis/clients/jedis/providers/ClusterConnectionProvider.java

@@ -19,6 +19,8 @@
 
 public class ClusterConnectionProvider implements ConnectionProvider {
 
+  private static final String INIT_NO_ERROR_PROPERTY = "jedis.cluster.initNoError";
+
   protected final JedisClusterInfoCache cache;
 
   public ClusterConnectionProvider(Set<HostAndPort> clusterNodes, JedisClientConfig clientConfig) {
@@ -53,6 +55,9 @@ private void initializeSlotsCache(Set<HostAndPort> startNodes, JedisClientConfig
       }
     }
 
+    if (System.getProperty(INIT_NO_ERROR_PROPERTY) != null) {
+      return;
+    }
     JedisClusterOperationException uninitializedException
         = new JedisClusterOperationException("Could not initialize cluster slots cache.");
     uninitializedException.addSuppressed(firstException);

src/test/java/redis/clients/jedis/misc/ClusterInitErrorTest.java

@@ -0,0 +1,40 @@
+package redis.clients.jedis.misc;
+
+import java.util.Collections;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Test;
+import redis.clients.jedis.DefaultJedisClientConfig;
+import redis.clients.jedis.HostAndPorts;
+import redis.clients.jedis.JedisCluster;
+import redis.clients.jedis.exceptions.JedisClusterOperationException;
+
+public class ClusterInitErrorTest {
+
+  private static final String INIT_NO_ERROR_PROPERTY = "jedis.cluster.initNoError";
+
+  @After
+  public void cleanUp() {
+    System.getProperties().remove(INIT_NO_ERROR_PROPERTY);
+  }
+
+  @Test(expected = JedisClusterOperationException.class)
+  public void initError() {
+    Assert.assertNull(System.getProperty(INIT_NO_ERROR_PROPERTY));
+    try (JedisCluster cluster = new JedisCluster(
+        Collections.singleton(HostAndPorts.getRedisServers().get(0)),
+        DefaultJedisClientConfig.builder().password("foobared").build())) {
+      throw new IllegalStateException("should not reach here");
+    }
+  }
+
+  @Test
+  public void initNoError() {
+    System.setProperty(INIT_NO_ERROR_PROPERTY, "");
+    try (JedisCluster cluster = new JedisCluster(
+        Collections.singleton(HostAndPorts.getRedisServers().get(0)),
+        DefaultJedisClientConfig.builder().password("foobared").build())) {
+      Assert.assertThrows(JedisClusterOperationException.class, () -> cluster.get("foo"));
+    }
+  }
+}