- introduce forceActiveCluster by duration

- fix formatting

Author: atakavci

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

@@ -165,8 +165,8 @@ public MultiClusterClientConfig(ClusterConfig[] clusterConfigs) {
         if (clusterConfigs == null || clusterConfigs.length < 1) throw new JedisValidationException(
             "ClusterClientConfigs are required for MultiClusterPooledConnectionProvider");
         for (ClusterConfig clusterConfig : clusterConfigs) {
-            if (clusterConfig == null) throw new IllegalArgumentException(
-                "ClusterClientConfigs must not contain null elements");
+            if (clusterConfig == null)
+                throw new IllegalArgumentException("ClusterClientConfigs must not contain null elements");
         }
         this.clusterConfigs = clusterConfigs;
     }

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

@@ -378,7 +378,7 @@ private Cluster waitForInitialHealthyCluster() {
 
         log.info("Selecting initial cluster from {} configured clusters", sortedClusters.size());
 
-        // Select clusters in weight order
+        // Select cluster in weight order
         for (Map.Entry<Endpoint, Cluster> entry : sortedClusters) {
             Endpoint endpoint = entry.getKey();
             Cluster cluster = entry.getValue();
@@ -519,6 +519,21 @@ public void setActiveCluster(Endpoint endpoint) {
         setActiveCluster(cluster, true);
     }
 
+    public void forceActiveCluster(Endpoint endpoint, long forcedActiveDuration) {
+        Cluster cluster = multiClusterMap.get(endpoint);
+        cluster.clearGracePeriod();
+        if (!cluster.isHealthy()) {
+            throw new JedisValidationException("Provided endpoint: " + endpoint
+                + " is not healthy. Please consider a healthy endpoint from the configuration");
+        }
+        multiClusterMap.entrySet().stream().forEach(entry -> {
+            if (entry.getKey() != endpoint) {
+                entry.getValue().setGracePeriod(forcedActiveDuration);
+            }
+        });
+        setActiveCluster(endpoint);
+    }
+
     private boolean setActiveCluster(Cluster cluster, boolean validateConnection) {
         // Cluster cluster = clusterEntry.getValue();
         // Field-level synchronization is used to avoid the edge case in which
@@ -710,7 +725,17 @@ public boolean isInGracePeriod() {
          * Sets the grace period for this cluster
          */
         public void setGracePeriod() {
-            gracePeriodEndsAt = System.currentTimeMillis() + multiClusterClientConfig.getGracePeriod();
+            setGracePeriod(multiClusterClientConfig.getGracePeriod());
+        }
+
+        public void setGracePeriod(long gracePeriod) {
+            long endTime = System.currentTimeMillis() + gracePeriod;
+            if (endTime < gracePeriodEndsAt) return;
+            gracePeriodEndsAt = endTime;
+        }
+
+        public void clearGracePeriod() {
+            gracePeriodEndsAt = 0;
         }
 
         /**