Expose index health and status to the _stats API (#81954)

Resolves #80413

server/src/main/java/org/elasticsearch/action/admin/indices/stats/IndexStats.java

@@ -8,6 +8,10 @@
 
 package org.elasticsearch.action.admin.indices.stats;
 
+import org.elasticsearch.cluster.health.ClusterHealthStatus;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.core.Nullable;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -20,11 +24,23 @@ public class IndexStats implements Iterable<IndexShardStats> {
 
     private final String uuid;
 
+    private final ClusterHealthStatus health;
+
+    private final IndexMetadata.State state;
+
     private final ShardStats shards[];
 
-    public IndexStats(String index, String uuid, ShardStats[] shards) {
+    public IndexStats(
+        String index,
+        String uuid,
+        @Nullable ClusterHealthStatus health,
+        @Nullable IndexMetadata.State state,
+        ShardStats[] shards
+    ) {
         this.index = index;
         this.uuid = uuid;
+        this.health = health;
+        this.state = state;
         this.shards = shards;
     }
 
@@ -36,6 +52,14 @@ public String getUuid() {
         return uuid;
     }
 
+    public ClusterHealthStatus getHealth() {
+        return health;
+    }
+
+    public IndexMetadata.State getState() {
+        return state;
+    }
+
     public ShardStats[] getShards() {
         return this.shards;
     }
@@ -48,11 +72,7 @@ public Map<Integer, IndexShardStats> getIndexShards() {
         }
         Map<Integer, List<ShardStats>> tmpIndexShards = new HashMap<>();
         for (ShardStats shard : shards) {
-            List<ShardStats> lst = tmpIndexShards.get(shard.getShardRouting().id());
-            if (lst == null) {
-                lst = new ArrayList<>();
-                tmpIndexShards.put(shard.getShardRouting().id(), lst);
-            }
+            List<ShardStats> lst = tmpIndexShards.computeIfAbsent(shard.getShardRouting().id(), ignored -> new ArrayList<>());
             lst.add(shard);
         }
         indexShards = new HashMap<>();
@@ -106,11 +126,15 @@ public CommonStats getPrimaries() {
     public static class IndexStatsBuilder {
         private final String indexName;
         private final String uuid;
+        private final ClusterHealthStatus health;
+        private final IndexMetadata.State state;
         private final List<ShardStats> shards = new ArrayList<>();
 
-        public IndexStatsBuilder(String indexName, String uuid) {
+        public IndexStatsBuilder(String indexName, String uuid, @Nullable ClusterHealthStatus health, @Nullable IndexMetadata.State state) {
             this.indexName = indexName;
             this.uuid = uuid;
+            this.health = health;
+            this.state = state;
         }
 
         public IndexStatsBuilder add(ShardStats shardStats) {
@@ -119,7 +143,7 @@ public IndexStatsBuilder add(ShardStats shardStats) {
         }
 
         public IndexStats build() {
-            return new IndexStats(indexName, uuid, shards.toArray(new ShardStats[shards.size()]));
+            return new IndexStats(indexName, uuid, health, state, shards.toArray(new ShardStats[shards.size()]));
         }
     }
 }

server/src/main/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsResponse.java

@@ -8,9 +8,14 @@
 
 package org.elasticsearch.action.admin.indices.stats;
 
+import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.indices.stats.IndexStats.IndexStatsBuilder;
 import org.elasticsearch.action.support.DefaultShardOperationFailedException;
 import org.elasticsearch.action.support.broadcast.BroadcastResponse;
+import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.health.ClusterHealthStatus;
+import org.elasticsearch.cluster.health.ClusterIndexHealth;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -21,31 +26,62 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import static java.util.Collections.unmodifiableMap;
 
 public class IndicesStatsResponse extends BroadcastResponse {
 
-    private ShardStats[] shards;
+    private final Map<String, ClusterHealthStatus> indexHealthMap;
+
+    private final Map<String, IndexMetadata.State> indexStateMap;
+
+    private final ShardStats[] shards;
 
     private Map<ShardRouting, ShardStats> shardStatsMap;
 
     IndicesStatsResponse(StreamInput in) throws IOException {
         super(in);
-        shards = in.readArray(ShardStats::new, (size) -> new ShardStats[size]);
+        shards = in.readArray(ShardStats::new, ShardStats[]::new);
+        if (in.getVersion().onOrAfter(Version.V_8_1_0)) {
+            indexHealthMap = in.readMap(StreamInput::readString, ClusterHealthStatus::readFrom);
+            indexStateMap = in.readMap(StreamInput::readString, IndexMetadata.State::readFrom);
+        } else {
+            indexHealthMap = Map.of();
+            indexStateMap = Map.of();
+        }
     }
 
     IndicesStatsResponse(
         ShardStats[] shards,
         int totalShards,
         int successfulShards,
         int failedShards,
-        List<DefaultShardOperationFailedException> shardFailures
+        List<DefaultShardOperationFailedException> shardFailures,
+        ClusterState clusterState
     ) {
         super(totalShards, successfulShards, failedShards, shardFailures);
         this.shards = shards;
+        Objects.requireNonNull(clusterState);
+        Objects.requireNonNull(shards);
+        Map<String, ClusterHealthStatus> indexHealthModifiableMap = new HashMap<>();
+        Map<String, IndexMetadata.State> indexStateModifiableMap = new HashMap<>();
+        for (ShardStats shard : shards) {
+            Index index = shard.getShardRouting().index();
+            IndexMetadata indexMetadata = clusterState.getMetadata().index(index);
+            if (indexMetadata != null) {
+                indexHealthModifiableMap.computeIfAbsent(
+                    index.getName(),
+                    ignored -> new ClusterIndexHealth(indexMetadata, clusterState.routingTable().index(index)).getStatus()
+                );
+                indexStateModifiableMap.computeIfAbsent(index.getName(), ignored -> indexMetadata.getState());
+            }
+        }
+        indexHealthMap = unmodifiableMap(indexHealthModifiableMap);
+        indexStateMap = unmodifiableMap(indexStateModifiableMap);
     }
 
     public Map<ShardRouting, ShardStats> asMap() {
@@ -83,7 +119,7 @@ public Map<String, IndexStats> getIndices() {
             Index index = shard.getShardRouting().index();
             IndexStatsBuilder indexStatsBuilder = indexToIndexStatsBuilder.computeIfAbsent(
                 index.getName(),
-                k -> new IndexStatsBuilder(k, index.getUUID())
+                k -> new IndexStatsBuilder(k, index.getUUID(), indexHealthMap.get(index.getName()), indexStateMap.get(index.getName()))
             );
             indexStatsBuilder.add(shard);
         }
@@ -128,6 +164,10 @@ public CommonStats getPrimaries() {
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
         out.writeArray(shards);
+        if (out.getVersion().onOrAfter(Version.V_8_1_0)) {
+            out.writeMap(indexHealthMap, StreamOutput::writeString, (o, s) -> s.writeTo(o));
+            out.writeMap(indexStateMap, StreamOutput::writeString, (o, s) -> s.writeTo(o));
+        }
     }
 
     @Override
@@ -157,6 +197,12 @@ protected void addCustomXContentFields(XContentBuilder builder, Params params) t
             for (IndexStats indexStats : getIndices().values()) {
                 builder.startObject(indexStats.getIndex());
                 builder.field("uuid", indexStats.getUuid());
+                if (indexStats.getHealth() != null) {
+                    builder.field("health", indexStats.getHealth().toString().toLowerCase(Locale.ROOT));
+                }
+                if (indexStats.getState() != null) {
+                    builder.field("status", indexStats.getState().toString().toLowerCase(Locale.ROOT));
+                }
                 builder.startObject("primaries");
                 indexStats.getPrimaries().toXContent(builder, params);
                 builder.endObject();

server/src/main/java/org/elasticsearch/action/admin/indices/stats/TransportIndicesStatsAction.java

@@ -99,7 +99,8 @@ protected IndicesStatsResponse newResponse(
             totalShards,
             successfulShards,
             failedShards,
-            shardFailures
+            shardFailures,
+            clusterState
         );
     }
 

server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetadata.java

@@ -122,7 +122,7 @@ public class IndexMetadata implements Diffable<IndexMetadata>, ToXContentFragmen
         EnumSet.of(ClusterBlockLevel.WRITE)
     );
 
-    public enum State {
+    public enum State implements Writeable {
         OPEN((byte) 0),
         CLOSE((byte) 1);
 
@@ -145,6 +145,15 @@ public static State fromId(byte id) {
             throw new IllegalStateException("No state match for id [" + id + "]");
         }
 
+        public static State readFrom(StreamInput in) throws IOException {
+            byte id = in.readByte();
+            return switch (id) {
+                case 0 -> OPEN;
+                case 1 -> CLOSE;
+                default -> throw new IllegalStateException("No state match for id [" + id + "]");
+            };
+        }
+
         public static State fromString(String state) {
             if ("open".equals(state)) {
                 return OPEN;
@@ -153,6 +162,11 @@ public static State fromString(String state) {
             }
             throw new IllegalStateException("No state match for [" + state + "]");
         }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            out.writeByte(id);
+        }
     }
 
     static Setting<Integer> buildNumberOfShardsSetting() {

server/src/test/java/org/elasticsearch/action/admin/indices/rollover/TransportRolloverActionTests.java

@@ -422,7 +422,8 @@ public static IndicesStatsResponse randomIndicesStatsResponse(final IndexMetadat
             shardStats.size(),
             shardStats.size(),
             0,
-            emptyList()
+            emptyList(),
+            ClusterState.EMPTY_STATE
         );
     }
 }

server/src/test/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsResponseTests.java

@@ -8,6 +8,7 @@
 
 package org.elasticsearch.action.admin.indices.stats;
 
+import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.cluster.routing.ShardRoutingState;
 import org.elasticsearch.cluster.routing.TestShardRouting;
@@ -35,7 +36,7 @@
 public class IndicesStatsResponseTests extends ESTestCase {
 
     public void testInvalidLevel() {
-        final IndicesStatsResponse response = new IndicesStatsResponse(null, 0, 0, 0, null);
+        final IndicesStatsResponse response = new IndicesStatsResponse(new ShardStats[0], 0, 0, 0, null, ClusterState.EMPTY_STATE);
         final String level = randomAlphaOfLength(16);
         final ToXContent.Params params = new ToXContent.MapParams(Collections.singletonMap("level", level));
         final IllegalArgumentException e = expectThrows(
@@ -81,7 +82,8 @@ public void testGetIndices() {
             0,
             0,
             0,
-            null
+            null,
+            ClusterState.EMPTY_STATE
         );
         Map<String, IndexStats> indexStats = indicesStatsResponse.getIndices();
 

server/src/test/java/org/elasticsearch/action/admin/indices/stats/IndicesStatsTests.java

@@ -9,9 +9,14 @@
 package org.elasticsearch.action.admin.indices.stats;
 
 import org.elasticsearch.action.ActionFuture;
+import org.elasticsearch.action.admin.indices.close.CloseIndexRequest;
 import org.elasticsearch.action.index.IndexResponse;
 import org.elasticsearch.action.support.DefaultShardOperationFailedException;
+import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.action.support.WriteRequest.RefreshPolicy;
+import org.elasticsearch.cluster.ClusterState;
+import org.elasticsearch.cluster.health.ClusterHealthStatus;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.IndexModule;
@@ -23,6 +28,7 @@
 import org.elasticsearch.xcontent.XContentFactory;
 
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
@@ -143,6 +149,41 @@ public void testUuidOnRootStatsIndices() {
         assertEquals(uuid, rsp.getIndex("test").getUuid());
     }
 
+    public void testIndexHealth() {
+        String greenIndex = "green-index";
+        createIndex(greenIndex);
+        String yellowIndex = "yellow-index";
+        createIndex(yellowIndex, Settings.builder().put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1).build());
+
+        IndicesStatsResponse rsp = client().admin().indices().prepareStats().all().get();
+
+        IndexStats greenIndexStats = rsp.getIndex(greenIndex);
+        assertEquals(ClusterHealthStatus.GREEN, greenIndexStats.getHealth());
+
+        IndexStats yellowIndexStats = rsp.getIndex(yellowIndex);
+        assertEquals(ClusterHealthStatus.YELLOW, yellowIndexStats.getHealth());
+    }
+
+    public void testIndexState() throws ExecutionException, InterruptedException {
+        String openIndex = "open-index";
+        createIndex(openIndex);
+        String closeIndex = "close-index";
+        createIndex(closeIndex);
+
+        client().admin().indices().close(new CloseIndexRequest(closeIndex)).get();
+
+        IndicesStatsResponse rsp = client().admin()
+            .indices()
+            .prepareStats()
+            .setIndicesOptions(IndicesOptions.STRICT_EXPAND_OPEN_CLOSED)
+            .get();
+        IndexStats openIndexStats = rsp.getIndex(openIndex);
+        assertEquals(IndexMetadata.State.OPEN, openIndexStats.getState());
+
+        IndexStats closeIndexStats = rsp.getIndex(closeIndex);
+        assertEquals(IndexMetadata.State.CLOSE, closeIndexStats.getState());
+    }
+
     /**
      * Gives access to package private IndicesStatsResponse constructor for test purpose.
      **/
@@ -151,8 +192,9 @@ public static IndicesStatsResponse newIndicesStatsResponse(
         int totalShards,
         int successfulShards,
         int failedShards,
-        List<DefaultShardOperationFailedException> shardFailures
+        List<DefaultShardOperationFailedException> shardFailures,
+        ClusterState clusterState
     ) {
-        return new IndicesStatsResponse(shards, totalShards, successfulShards, failedShards, shardFailures);
+        return new IndicesStatsResponse(shards, totalShards, successfulShards, failedShards, shardFailures, clusterState);
     }
 }

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/WaitForNoFollowersStepTests.java

@@ -14,6 +14,7 @@
 import org.elasticsearch.action.admin.indices.stats.IndicesStatsRequest;
 import org.elasticsearch.action.admin.indices.stats.IndicesStatsResponse;
 import org.elasticsearch.action.admin.indices.stats.ShardStats;
+import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.common.Strings;
@@ -147,7 +148,7 @@ public void testNoShardStats() {
         ShardStats sStats = new ShardStats(null, mockShardPath(), null, null, null, null);
         ShardStats[] shardStats = new ShardStats[1];
         shardStats[0] = sStats;
-        mockIndexStatsCall(indexName, new IndexStats(indexName, "uuid", shardStats));
+        mockIndexStatsCall(indexName, new IndexStats(indexName, "uuid", ClusterHealthStatus.GREEN, IndexMetadata.State.OPEN, shardStats));
 
         final SetOnce<Boolean> conditionMetHolder = new SetOnce<>();
         final SetOnce<ToXContentObject> stepInfoHolder = new SetOnce<>();
@@ -233,7 +234,7 @@ private IndexStats randomIndexStats(boolean isLeaderIndex, int numOfShards) {
         for (int i = 0; i < numOfShards; i++) {
             shardStats[i] = randomShardStats(isLeaderIndex);
         }
-        return new IndexStats(randomAlphaOfLength(5), randomAlphaOfLength(10), shardStats);
+        return new IndexStats(randomAlphaOfLength(5), randomAlphaOfLength(10), null, null, shardStats);
     }
 
     private ShardStats randomShardStats(boolean isLeaderIndex) {

x-pack/plugin/monitoring/src/test/java/org/elasticsearch/xpack/monitoring/collector/indices/IndicesStatsMonitoringDocTests.java

@@ -51,6 +51,8 @@ public void setUp() throws Exception {
             new IndexStats(
                 "index-0",
                 "dcvO5uZATE-EhIKc3tk9Bg",
+                null,
+                null,
                 new ShardStats[] {
                     // Primaries
                     new ShardStats(mockShardRouting(true), mockShardPath(), mockCommonStats(), null, null, null),