Revert "Removed index level metadata election #17233"

This reverts commit 1264ee79b61690fc02a262c1a6680fab9e53235a.

core/src/main/java/org/elasticsearch/gateway/Gateway.java

@@ -19,6 +19,9 @@
 
 package org.elasticsearch.gateway;
 
+import com.carrotsearch.hppc.ObjectFloatHashMap;
+import com.carrotsearch.hppc.ObjectHashSet;
+import com.carrotsearch.hppc.cursors.ObjectCursor;
 import org.apache.lucene.util.IOUtils;
 import org.elasticsearch.action.FailedNodeException;
 import org.elasticsearch.cluster.ClusterChangedEvent;
@@ -31,11 +34,15 @@ import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.discovery.Discovery;
 import org.elasticsearch.env.NodeEnvironment;
+import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.NodeServicesProvider;
 import org.elasticsearch.indices.IndicesService;
 
+import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.function.Supplier;
 
 /**
@@ -84,6 +91,7 @@ public class Gateway extends AbstractComponent implements ClusterStateListener {
             }
         }
 
+        ObjectFloatHashMap<Index> indices = new ObjectFloatHashMap<>();
         MetaData electedGlobalState = null;
         int found = 0;
         for (TransportNodesListGatewayMetaState.NodeGatewayMetaState nodeState : nodesState) {
@@ -96,34 +104,65 @@ public class Gateway extends AbstractComponent implements ClusterStateListener {
             } else if (nodeState.metaData().version() > electedGlobalState.version()) {
                 electedGlobalState = nodeState.metaData();
             }
+            for (ObjectCursor<IndexMetaData> cursor : nodeState.metaData().indices().values()) {
+                indices.addTo(cursor.value.getIndex(), 1);
+            }
         }
         if (found < requiredAllocation) {
             listener.onFailure("found [" + found + "] metadata states, required [" + requiredAllocation + "]");
             return;
         }
-        // verify index metadata
-        MetaData.Builder metaDataBuilder = MetaData.builder(electedGlobalState);
-        for (IndexMetaData indexMetaData : electedGlobalState) {
-            try {
-                if (indexMetaData.getState() == IndexMetaData.State.OPEN) {
-                    // verify that we can actually create this index - if not we recover it as closed with lots of warn logs
-                    indicesService.verifyIndexMetadata(nodeServicesProvider, indexMetaData);
+        // update the global state, and clean the indices, we elect them in the next phase
+        MetaData.Builder metaDataBuilder = MetaData.builder(electedGlobalState).removeAllIndices();
+
+        assert !indices.containsKey(null);
+        final Object[] keys = indices.keys;
+        for (int i = 0; i < keys.length; i++) {
+            if (keys[i] != null) {
+                Index index = (Index) keys[i];
+                IndexMetaData electedIndexMetaData = null;
+                int indexMetaDataCount = 0;
+                for (TransportNodesListGatewayMetaState.NodeGatewayMetaState nodeState : nodesState) {
+                    if (nodeState.metaData() == null) {
+                        continue;
+                    }
+                    IndexMetaData indexMetaData = nodeState.metaData().index(index);
+                    if (indexMetaData == null) {
+                        continue;
+                    }
+                    if (electedIndexMetaData == null) {
+                        electedIndexMetaData = indexMetaData;
+                    } else if (indexMetaData.getVersion() > electedIndexMetaData.getVersion()) {
+                        electedIndexMetaData = indexMetaData;
+                    }
+                    indexMetaDataCount++;
+                }
+                if (electedIndexMetaData != null) {
+                    if (indexMetaDataCount < requiredAllocation) {
+                        logger.debug("[{}] found [{}], required [{}], not adding", index, indexMetaDataCount, requiredAllocation);
+                    } // TODO if this logging statement is correct then we are missing an else here
+                    try {
+                        if (electedIndexMetaData.getState() == IndexMetaData.State.OPEN) {
+                            // verify that we can actually create this index - if not we recover it as closed with lots of warn logs
+                            indicesService.verifyIndexMetadata(nodeServicesProvider, electedIndexMetaData);
+                        }
+                    } catch (Exception e) {
+                        logger.warn("recovering index {} failed - recovering as closed", e, electedIndexMetaData.getIndex());
+                        electedIndexMetaData = IndexMetaData.builder(electedIndexMetaData).state(IndexMetaData.State.CLOSE).build();
+                    }
+
+                    metaDataBuilder.put(electedIndexMetaData, false);
                 }
-            } catch (Exception e) {
-                logger.warn("recovering index {} failed - recovering as closed", e, indexMetaData.getIndex());
-                indexMetaData = IndexMetaData.builder(indexMetaData).state(IndexMetaData.State.CLOSE).build();
-                metaDataBuilder.put(indexMetaData, true);
             }
         }
         ClusterState.Builder builder = ClusterState.builder(clusterService.state().getClusterName());
         builder.metaData(metaDataBuilder);
         listener.onSuccess(builder.build());
     }
-
     public void reset() throws Exception {
         try {
             Path[] dataPaths = nodeEnv.nodeDataPaths();
-            logger.trace("removing node data paths: [{}]", (Object) dataPaths);
+            logger.trace("removing node data paths: [{}]", (Object)dataPaths);
             IOUtils.rm(dataPaths);
         } catch (Exception ex) {
             logger.debug("failed to delete shard locations", ex);