Cleanup Redundant Futures in Recovery Code (#48805)

Follow up to #48110 cleaning up the redundant future
uses that were left over from that change.

Author: original-brownbear

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -54,6 +54,7 @@
 import org.elasticsearch.cluster.routing.RecoverySource.SnapshotRecoverySource;
 import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.common.Booleans;
+import org.elasticsearch.common.CheckedConsumer;
 import org.elasticsearch.common.CheckedFunction;
 import org.elasticsearch.common.CheckedRunnable;
 import org.elasticsearch.common.Nullable;
@@ -1787,34 +1788,38 @@ public ShardPath shardPath() {
         return path;
     }
 
-    public boolean recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdateConsumer,
-                                                List<IndexShard> localShards) throws IOException {
+    public void recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdateConsumer, List<IndexShard> localShards,
+                                       ActionListener<Boolean> listener) throws IOException {
         assert shardRouting.primary() : "recover from local shards only makes sense if the shard is a primary shard";
         assert recoveryState.getRecoverySource().getType() == RecoverySource.Type.LOCAL_SHARDS : "invalid recovery type: " +
             recoveryState.getRecoverySource();
         final List<LocalShardSnapshot> snapshots = new ArrayList<>();
+        final ActionListener<Boolean> recoveryListener = ActionListener.runBefore(listener, () -> IOUtils.close(snapshots));
+        boolean success = false;
         try {
             for (IndexShard shard : localShards) {
                 snapshots.add(new LocalShardSnapshot(shard));
             }
-
             // we are the first primary, recover from the gateway
             // if its post api allocation, the index should exists
             assert shardRouting.primary() : "recover from local shards only makes sense if the shard is a primary shard";
             StoreRecovery storeRecovery = new StoreRecovery(shardId, logger);
-            return storeRecovery.recoverFromLocalShards(mappingUpdateConsumer, this, snapshots);
+            storeRecovery.recoverFromLocalShards(mappingUpdateConsumer, this, snapshots, recoveryListener);
+            success = true;
         } finally {
-            IOUtils.close(snapshots);
+            if (success == false) {
+                IOUtils.close(snapshots);
+            }
         }
     }
 
-    public boolean recoverFromStore() {
+    public void recoverFromStore(ActionListener<Boolean> listener) {
         // we are the first primary, recover from the gateway
         // if its post api allocation, the index should exists
         assert shardRouting.primary() : "recover from store only makes sense if the shard is a primary shard";
         assert shardRouting.initializing() : "can only start recovery on initializing shard";
         StoreRecovery storeRecovery = new StoreRecovery(shardId, logger);
-        return storeRecovery.recoverFromStore(this);
+        storeRecovery.recoverFromStore(this, listener);
     }
 
     public void restoreFromRepository(Repository repository, ActionListener<Boolean> listener) {
@@ -2484,17 +2489,7 @@ public void startRecovery(RecoveryState recoveryState, PeerRecoveryTargetService
         switch (recoveryState.getRecoverySource().getType()) {
             case EMPTY_STORE:
             case EXISTING_STORE:
-                markAsRecovering("from store", recoveryState); // mark the shard as recovering on the cluster state thread
-                threadPool.generic().execute(() -> {
-                    try {
-                        if (recoverFromStore()) {
-                            recoveryListener.onRecoveryDone(recoveryState);
-                        }
-                    } catch (Exception e) {
-                        recoveryListener.onRecoveryFailure(recoveryState,
-                            new RecoveryFailedException(recoveryState, null, e), true);
-                    }
-                });
+                executeRecovery("from store", recoveryState, recoveryListener, this::recoverFromStore);
                 break;
             case PEER:
                 try {
@@ -2507,17 +2502,9 @@ public void startRecovery(RecoveryState recoveryState, PeerRecoveryTargetService
                 }
                 break;
             case SNAPSHOT:
-                markAsRecovering("from snapshot", recoveryState); // mark the shard as recovering on the cluster state thread
-                SnapshotRecoverySource recoverySource = (SnapshotRecoverySource) recoveryState.getRecoverySource();
-                threadPool.generic().execute(
-                    ActionRunnable.<Boolean>wrap(ActionListener.wrap(r -> {
-                            if (r) {
-                                recoveryListener.onRecoveryDone(recoveryState);
-                            }
-                        },
-                        e -> recoveryListener.onRecoveryFailure(recoveryState, new RecoveryFailedException(recoveryState, null, e), true)),
-                        restoreListener -> restoreFromRepository(
-                            repositoriesService.repository(recoverySource.snapshot().getRepository()), restoreListener)));
+                final String repo = ((SnapshotRecoverySource) recoveryState.getRecoverySource()).snapshot().getRepository();
+                executeRecovery("from snapshot",
+                    recoveryState, recoveryListener, l -> restoreFromRepository(repositoriesService.repository(repo), l));
                 break;
             case LOCAL_SHARDS:
                 final IndexMetaData indexMetaData = indexSettings().getIndexMetaData();
@@ -2542,18 +2529,9 @@ public void startRecovery(RecoveryState recoveryState, PeerRecoveryTargetService
 
                 if (numShards == startedShards.size()) {
                     assert requiredShards.isEmpty() == false;
-                    markAsRecovering("from local shards", recoveryState); // mark the shard as recovering on the cluster state thread
-                    threadPool.generic().execute(() -> {
-                        try {
-                            if (recoverFromLocalShards(mappingUpdateConsumer, startedShards.stream()
-                                .filter((s) -> requiredShards.contains(s.shardId())).collect(Collectors.toList()))) {
-                                recoveryListener.onRecoveryDone(recoveryState);
-                            }
-                        } catch (Exception e) {
-                            recoveryListener.onRecoveryFailure(recoveryState,
-                                new RecoveryFailedException(recoveryState, null, e), true);
-                        }
-                    });
+                    executeRecovery("from local shards", recoveryState, recoveryListener,
+                        l -> recoverFromLocalShards(mappingUpdateConsumer,
+                            startedShards.stream().filter((s) -> requiredShards.contains(s.shardId())).collect(Collectors.toList()), l));
                 } else {
                     final RuntimeException e;
                     if (numShards == -1) {
@@ -2571,6 +2549,17 @@ public void startRecovery(RecoveryState recoveryState, PeerRecoveryTargetService
         }
     }
 
+    private void executeRecovery(String reason, RecoveryState recoveryState, PeerRecoveryTargetService.RecoveryListener recoveryListener,
+                                 CheckedConsumer<ActionListener<Boolean>, Exception> action) {
+        markAsRecovering(reason, recoveryState); // mark the shard as recovering on the cluster state thread
+        threadPool.generic().execute(ActionRunnable.wrap(ActionListener.wrap(r -> {
+                if (r) {
+                    recoveryListener.onRecoveryDone(recoveryState);
+                }
+            },
+            e -> recoveryListener.onRecoveryFailure(recoveryState, new RecoveryFailedException(recoveryState, null, e), true)), action));
+    }
+
     /**
      * Returns whether the shard is a relocated primary, i.e. not in charge anymore of replicating changes (see {@link ReplicationTracker}).
      */

server/src/main/java/org/elasticsearch/index/shard/StoreRecovery.java

@@ -31,7 +31,6 @@
 import org.apache.lucene.store.IndexInput;
 import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.action.support.PlainActionFuture;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.metadata.MappingMetaData;
 import org.elasticsearch.cluster.routing.RecoverySource;
@@ -81,31 +80,27 @@ final class StoreRecovery {
      * exist on disk ie. has been previously allocated or if the shard is a brand new allocation without pre-existing index
      * files / transaction logs. This
      * @param indexShard the index shard instance to recovery the shard into
-     * @return  <code>true</code> if the shard has been recovered successfully, <code>false</code> if the recovery
-     * has been ignored due to a concurrent modification of if the clusters state has changed due to async updates.
+     * @param listener resolves to <code>true</code> if the shard has been recovered successfully, <code>false</code> if the recovery
+     *                 has been ignored due to a concurrent modification of if the clusters state has changed due to async updates.
      * @see Store
      */
-    boolean recoverFromStore(final IndexShard indexShard) {
+    void recoverFromStore(final IndexShard indexShard, ActionListener<Boolean> listener) {
         if (canRecover(indexShard)) {
             RecoverySource.Type recoveryType = indexShard.recoveryState().getRecoverySource().getType();
             assert recoveryType == RecoverySource.Type.EMPTY_STORE || recoveryType == RecoverySource.Type.EXISTING_STORE :
                 "expected store recovery type but was: " + recoveryType;
-            final PlainActionFuture<Boolean> future = PlainActionFuture.newFuture();
-            final ActionListener<Boolean> recoveryListener = recoveryListener(indexShard, future);
-            try {
+            ActionListener.completeWith(recoveryListener(indexShard, listener), () -> {
                 logger.debug("starting recovery from store ...");
                 internalRecoverFromStore(indexShard);
-                recoveryListener.onResponse(true);
-            } catch (Exception e) {
-                recoveryListener.onFailure(e);
-            }
-            return future.actionGet();
+                return true;
+            });
+        } else {
+            listener.onResponse(false);
         }
-        return false;
     }
 
-    boolean recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdateConsumer,
-                                        final IndexShard indexShard, final List<LocalShardSnapshot> shards) {
+    void recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdateConsumer, IndexShard indexShard,
+                                List<LocalShardSnapshot> shards, ActionListener<Boolean> listener) {
         if (canRecover(indexShard)) {
             RecoverySource.Type recoveryType = indexShard.recoveryState().getRecoverySource().getType();
             assert recoveryType == RecoverySource.Type.LOCAL_SHARDS: "expected local shards recovery type: " + recoveryType;
@@ -125,8 +120,7 @@ boolean recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdate
             Sort indexSort = indexShard.getIndexSort();
             final boolean hasNested = indexShard.mapperService().hasNested();
             final boolean isSplit = sourceMetaData.getNumberOfShards() < indexShard.indexSettings().getNumberOfShards();
-            final PlainActionFuture<Boolean> future = PlainActionFuture.newFuture();
-            ActionListener.completeWith(recoveryListener(indexShard, future), () -> {
+            ActionListener.completeWith(recoveryListener(indexShard, listener), () -> {
                 logger.debug("starting recovery from local shards {}", shards);
                 try {
                     final Directory directory = indexShard.store().directory(); // don't close this directory!!
@@ -146,10 +140,9 @@ boolean recoverFromLocalShards(BiConsumer<String, MappingMetaData> mappingUpdate
                     throw new IndexShardRecoveryException(indexShard.shardId(), "failed to recover from local shards", ex);
                 }
             });
-            assert future.isDone();
-            return future.actionGet();
+        } else {
+            listener.onResponse(false);
         }
-        return false;
     }
 
     void addIndices(final RecoveryState.Index indexRecoveryStats, final Directory target, final Sort indexSort, final Directory[] sources,

server/src/test/java/org/elasticsearch/index/shard/IndexShardIT.java

@@ -118,6 +118,7 @@
 import static org.elasticsearch.index.seqno.SequenceNumbers.NO_OPS_PERFORMED;
 import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_SEQ_NO;
 import static org.elasticsearch.index.shard.IndexShardTestCase.getTranslog;
+import static org.elasticsearch.index.shard.IndexShardTestCase.recoverFromStore;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailures;
@@ -641,7 +642,7 @@ public void testCircuitBreakerIncrementedByIndexShard() throws Exception {
     public static final IndexShard recoverShard(IndexShard newShard) throws IOException {
         DiscoveryNode localNode = new DiscoveryNode("foo", buildNewFakeTransportAddress(), emptyMap(), emptySet(), Version.CURRENT);
         newShard.markAsRecovering("store", new RecoveryState(newShard.routingEntry(), localNode, null));
-        assertTrue(newShard.recoverFromStore());
+        recoverFromStore(newShard);
         IndexShardTestCase.updateRoutingEntry(newShard, newShard.routingEntry().moveToStarted());
         return newShard;
     }