Speedup computing cluster health

server/src/main/java/org/elasticsearch/cluster/health/ClusterStateHealth.java

@@ -10,7 +10,7 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.routing.IndexRoutingTable;
-import org.elasticsearch.cluster.routing.ShardRouting;
+import org.elasticsearch.cluster.routing.RoutingNodes;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
@@ -20,7 +20,6 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
@@ -104,13 +103,9 @@ public ClusterStateHealth(final ClusterState clusterState, final String[] concre
         if (computeStatus.equals(ClusterHealthStatus.GREEN)) {
             this.activeShardsPercent = 100;
         } else {
-            List<ShardRouting> shardRoutings = clusterState.getRoutingTable().allShards();
-            int activeShardCount = 0;
-            int totalShardCount = 0;
-            for (ShardRouting shardRouting : shardRoutings) {
-                if (shardRouting.active()) activeShardCount++;
-                totalShardCount++;
-            }
+            RoutingNodes routingNodes = clusterState.getRoutingNodes();
+            int activeShardCount = routingNodes.getActiveShardCount();
+            int totalShardCount = routingNodes.getTotalShardCount();
             this.activeShardsPercent = (((double) activeShardCount) / totalShardCount) * 100;
         }
     }

server/src/main/java/org/elasticsearch/cluster/routing/RoutingNodes.java

@@ -72,6 +72,10 @@ public class RoutingNodes implements Iterable<RoutingNode> {
 
     private int relocatingShards = 0;
 
+    private int activeShardCount = 0;
+
+    private int totalShardCount = 0;
+
     private final Map<String, Set<String>> attributeValuesByAttribute = new HashMap<>();
     private final Map<String, Recoveries> recoveriesPerNode = new HashMap<>();
 
@@ -95,6 +99,7 @@ public RoutingNodes(ClusterState clusterState, boolean readOnly) {
             for (IndexShardRoutingTable indexShard : indexRoutingTable) {
                 assert indexShard.primary != null;
                 for (ShardRouting shard : indexShard) {
+                    totalShardCount++;
                     // to get all the shards belonging to an index, including the replicas,
                     // we define a replica set and keep track of it. A replica set is identified
                     // by the ShardId, as this is common for primary and replicas.
@@ -107,6 +112,9 @@ public RoutingNodes(ClusterState clusterState, boolean readOnly) {
                             throw new IllegalArgumentException("Cannot have two different shards with same shard id on same node");
                         }
                         assignedShardsAdd(shard);
+                        if (shard.active()) {
+                            activeShardCount++;
+                        }
                         if (shard.relocating()) {
                             relocatingShards++;
                             // LinkedHashMap to preserve order.
@@ -273,6 +281,14 @@ public int getRelocatingShardCount() {
         return relocatingShards;
     }
 
+    public int getActiveShardCount() {
+        return activeShardCount;
+    }
+
+    public int getTotalShardCount() {
+        return totalShardCount;
+    }
+
     /**
      * Returns all shards that are not in the state UNASSIGNED with the same shard
      * ID as the given shard.