[ENGINE] Remove dirty flag and force boolean for refresh

Today we have a dirty flag indicating that a refresh must
be executed. We also allow users to bypass this by setting
a force=true boolean on the refresh request / command. All
these flags are unneeded since the SearcherManager has all
the information to do the right thing if it's dirty or not.

src/main/java/org/elasticsearch/action/admin/indices/refresh/RefreshRequest.java

@@ -37,7 +37,6 @@ import java.io.IOException;
  */
 public class RefreshRequest extends BroadcastOperationRequest<RefreshRequest> {
 
-    private boolean force = true;
 
     RefreshRequest() {
     }
@@ -54,26 +53,4 @@ public class RefreshRequest extends BroadcastOperationRequest<RefreshRequest> {
         super(indices);
     }
 
-    public boolean force() {
-        return force;
-    }
-
-    /**
-     * Forces calling refresh, overriding the check that dirty operations even happened. Defaults
-     * to true (note, still lightweight if no refresh is needed).
-     */
-    public RefreshRequest force(boolean force) {
-        this.force = force;
-        return this;
-    }
-
-    public void readFrom(StreamInput in) throws IOException {
-        super.readFrom(in);
-        force = in.readBoolean();
-    }
-
-    public void writeTo(StreamOutput out) throws IOException {
-        super.writeTo(out);
-        out.writeBoolean(force);
-    }
 }

src/main/java/org/elasticsearch/action/admin/indices/refresh/RefreshRequestBuilder.java

@@ -34,15 +34,6 @@ public class RefreshRequestBuilder extends BroadcastOperationRequestBuilder<Refr
         super(indicesClient, new RefreshRequest());
     }
 
-    /**
-     * Forces calling refresh, overriding the check that dirty operations even happened. Defaults
-     * to true (note, still lightweight if no refresh is needed).
-     */
-    public RefreshRequestBuilder setForce(boolean force) {
-        request.force(force);
-        return this;
-    }
-
     @Override
     protected void doExecute(ActionListener<RefreshResponse> listener) {
         client.refresh(request, listener);

src/main/java/org/elasticsearch/action/admin/indices/refresh/ShardRefreshRequest.java

@@ -31,29 +31,11 @@ import java.io.IOException;
  */
 class ShardRefreshRequest extends BroadcastShardOperationRequest {
 
-    private boolean force = true;
-
     ShardRefreshRequest() {
     }
 
     ShardRefreshRequest(ShardId shardId, RefreshRequest request) {
         super(shardId, request);
-        force = request.force();
-    }
-
-    public boolean force() {
-        return force;
     }
 
-    @Override
-    public void readFrom(StreamInput in) throws IOException {
-        super.readFrom(in);
-        force = in.readBoolean();
-    }
-
-    @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        super.writeTo(out);
-        out.writeBoolean(force);
-    }
 }

src/main/java/org/elasticsearch/action/admin/indices/refresh/TransportRefreshAction.java

@@ -107,8 +107,8 @@ public class TransportRefreshAction extends TransportBroadcastOperationAction<Re
     @Override
     protected ShardRefreshResponse shardOperation(ShardRefreshRequest request) throws ElasticsearchException {
         IndexShard indexShard = indicesService.indexServiceSafe(request.shardId().getIndex()).shardSafe(request.shardId().id());
-        indexShard.refresh("api", request.force());
-        logger.trace("{} refresh request executed, force: [{}]", indexShard.shardId(), request.force());
+        indexShard.refresh("api");
+        logger.trace("{} refresh request executed, force: [{}]", indexShard.shardId());
         return new ShardRefreshResponse(request.shardId());
     }
 

src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -355,7 +355,7 @@ public class TransportShardBulkAction extends TransportShardReplicationOperation
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_bulk", false);
+                indexShard.refresh("refresh_flag_bulk");
             } catch (Throwable e) {
                 // ignore
             }
@@ -620,7 +620,7 @@ public class TransportShardBulkAction extends TransportShardReplicationOperation
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_bulk", false);
+                indexShard.refresh("refresh_flag_bulk");
             } catch (Throwable e) {
                 // ignore
             }

src/main/java/org/elasticsearch/action/delete/TransportDeleteAction.java

@@ -182,7 +182,7 @@ public class TransportDeleteAction extends TransportShardReplicationOperationAct
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_delete", false);
+                indexShard.refresh("refresh_flag_delete");
             } catch (Exception e) {
                 // ignore
             }
@@ -202,7 +202,7 @@ public class TransportDeleteAction extends TransportShardReplicationOperationAct
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_delete", false);
+                indexShard.refresh("refresh_flag_delete");
             } catch (Exception e) {
                 // ignore
             }

src/main/java/org/elasticsearch/action/delete/TransportShardDeleteAction.java

@@ -92,7 +92,7 @@ public class TransportShardDeleteAction extends TransportShardReplicationOperati
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_delete", false);
+                indexShard.refresh("refresh_flag_delete");
             } catch (Exception e) {
                 // ignore
             }
@@ -117,7 +117,7 @@ public class TransportShardDeleteAction extends TransportShardReplicationOperati
 
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_delete", false);
+                indexShard.refresh("refresh_flag_delete");
             } catch (Exception e) {
                 // ignore
             }

src/main/java/org/elasticsearch/action/get/TransportGetAction.java

@@ -41,8 +41,6 @@ import org.elasticsearch.transport.TransportService;
  */
 public class TransportGetAction extends TransportShardSingleOperationAction<GetRequest, GetResponse> {
 
-    public static final boolean REFRESH_FORCE = false;
-
     private final IndicesService indicesService;
     private final boolean realtime;
 
@@ -90,7 +88,7 @@ public class TransportGetAction extends TransportShardSingleOperationAction<GetR
         IndexShard indexShard = indexService.shardSafe(shardId.id());
 
         if (request.refresh() && !request.realtime()) {
-            indexShard.refresh("refresh_flag_get", REFRESH_FORCE);
+            indexShard.refresh("refresh_flag_get");
         }
 
         GetResult result = indexShard.getService().get(request.type(), request.id(), request.fields(),

src/main/java/org/elasticsearch/action/get/TransportShardMultiGetAction.java

@@ -98,7 +98,7 @@ public class TransportShardMultiGetAction extends TransportShardSingleOperationA
         IndexShard indexShard = indexService.shardSafe(shardId.id());
 
         if (request.refresh() && !request.realtime()) {
-            indexShard.refresh("refresh_flag_mget", TransportGetAction.REFRESH_FORCE);
+            indexShard.refresh("refresh_flag_mget");
         }
 
         MultiGetShardResponse response = new MultiGetShardResponse();

src/main/java/org/elasticsearch/action/index/TransportIndexAction.java

@@ -205,7 +205,7 @@ public class TransportIndexAction extends TransportShardReplicationOperationActi
         }
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_index", false);
+                indexShard.refresh("refresh_flag_index");
             } catch (Throwable e) {
                 // ignore
             }
@@ -236,7 +236,7 @@ public class TransportIndexAction extends TransportShardReplicationOperationActi
         }
         if (request.refresh()) {
             try {
-                indexShard.refresh("refresh_flag_index", false);
+                indexShard.refresh("refresh_flag_index");
             } catch (Exception e) {
                 // ignore
             }

src/main/java/org/elasticsearch/index/engine/Engine.java

@@ -88,10 +88,9 @@ public interface Engine extends Closeable {
 
     /**
      * Refreshes the engine for new search operations to reflect the latest
-     * changes. Pass <tt>true</tt> if the refresh operation should include
-     * all the operations performed up to this call.
+     * changes.
      */
-    void refresh(String source, boolean force) throws EngineException;
+    void refresh(String source) throws EngineException;
 
     /**
      * Flushes the state of the engine, clearing memory.

src/main/java/org/elasticsearch/index/engine/internal/InternalEngine.java

@@ -111,9 +111,6 @@ public class InternalEngine implements Engine {
 
     private final AtomicBoolean isClosed = new AtomicBoolean(false);
     private volatile boolean closedOrFailed = false;
-    // flag indicating if a dirty operation has occurred since the last refresh
-    private volatile boolean dirty = false;
-
     private final AtomicBoolean optimizeMutex = new AtomicBoolean();
     // we use flushNeeded here, since if there are no changes, then the commit won't write
     // will not really happen, and then the commitUserData and the new translog will not be reflected
@@ -127,9 +124,6 @@ public class InternalEngine implements Engine {
     private final LiveVersionMap versionMap;
 
     private final Object[] dirtyLocks;
-
-    private final Object refreshMutex = new Object();
-
     private volatile Throwable failedEngine = null;
     private final Lock failEngineLock = new ReentrantLock();
     private final FailedEngineListener failedEngineListener;
@@ -350,7 +344,6 @@ public class InternalEngine implements Engine {
                     innerCreate(create, writer);
                 }
             }
-            dirty = true;
             flushNeeded = true;
         } catch (OutOfMemoryError | IllegalStateException | IOException t) {
             maybeFailEngine(t, "create");
@@ -458,7 +451,6 @@ public class InternalEngine implements Engine {
                     innerIndex(index, writer);
                 }
             }
-            dirty = true;
             flushNeeded = true;
         } catch (OutOfMemoryError | IllegalStateException | IOException t) {
             maybeFailEngine(t, "index");
@@ -482,7 +474,7 @@ public class InternalEngine implements Engine {
                 engineConfig.getThreadPool().executor(ThreadPool.Names.REFRESH).execute(new Runnable() {
                     public void run() {
                         try {
-                            refresh("version_table_full", false);
+                            refresh("version_table_full");
                         } catch (EngineClosedException ex) {
                             // ignore
                         }
@@ -551,7 +543,6 @@ public class InternalEngine implements Engine {
         try (InternalLock _ = readLock.acquire()) {
             final IndexWriter indexWriter = currentIndexWriter();
             innerDelete(delete, indexWriter);
-            dirty = true;
             flushNeeded = true;
         } catch (OutOfMemoryError | IllegalStateException | IOException t) {
             maybeFailEngine(t, "delete");
@@ -631,7 +622,6 @@ public class InternalEngine implements Engine {
 
             indexWriter.deleteDocuments(query);
             translog.add(new Translog.DeleteByQuery(delete));
-            dirty = true;
             flushNeeded = true;
         } catch (Throwable t) {
             maybeFailEngine(t, "delete_by_query");
@@ -640,7 +630,7 @@ public class InternalEngine implements Engine {
 
         // TODO: This is heavy, since we refresh, but we must do this because we don't know which documents were in fact deleted (i.e., our
         // versionMap isn't updated), so we must force a cutover to a new reader to "see" the deletions:
-        refresh("delete_by_query", true);
+        refresh("delete_by_query");
     }
 
     @Override
@@ -692,9 +682,7 @@ public class InternalEngine implements Engine {
               the store is closed so we need to make sure we increment it here
              */
             try {
-                // we are either dirty due to a document added or due to a
-                // finished merge - either way we should refresh
-                return dirty || !searcherManager.isSearcherCurrent();
+                return !searcherManager.isSearcherCurrent();
             } catch (IOException e) {
                 logger.error("failed to access searcher manager", e);
                 failEngine("failed to access searcher manager", e);
@@ -707,23 +695,12 @@ public class InternalEngine implements Engine {
     }
 
     @Override
-    public void refresh(String source, boolean force) throws EngineException {
+    public void refresh(String source) throws EngineException {
         // we obtain a read lock here, since we don't want a flush to happen while we are refreshing
         // since it flushes the index as well (though, in terms of concurrency, we are allowed to do it)
         try (InternalLock _ = readLock.acquire()) {
             ensureOpen();
-            // maybeRefresh will only allow one refresh to execute, and the rest will "pass through",
-            // but, we want to make sure not to loose ant refresh calls, if one is taking time
-            synchronized (refreshMutex) {
-                if (refreshNeeded() || force) {
-                    // we set dirty to false, even though the refresh hasn't happened yet
-                    // as the refresh only holds for data indexed before it. Any data indexed during
-                    // the refresh will not be part of it and will set the dirty flag back to true
-                    dirty = false;
-                    boolean refreshed = searcherManager.maybeRefresh();
-                    assert refreshed : "failed to refresh even though refreshMutex was acquired";
-                }
-            }
+            searcherManager.maybeRefreshBlocking();
         } catch (AlreadyClosedException e) {
             ensureOpen();
         } catch (EngineClosedException e) {
@@ -762,8 +739,6 @@ public class InternalEngine implements Engine {
                     if (onGoingRecoveries.get() > 0) {
                         throw new FlushNotAllowedEngineException(shardId, "Recovery is in progress, flush is not allowed");
                     }
-                    // disable refreshing, not dirty
-                    dirty = false;
                     try {
                         { // commit and close the current writer - we write the current tanslog ID just in case
                             final long translogId = translog.currentId();
@@ -813,7 +788,7 @@ public class InternalEngine implements Engine {
                             indexWriter.setCommitData(Collections.singletonMap(Translog.TRANSLOG_ID_KEY, Long.toString(translogId)));
                             indexWriter.commit();
                             // we need to refresh in order to clear older version values
-                            refresh("version_table_flush", true);
+                            refresh("version_table_flush");
                             // we need to move transient to current only after we refresh
                             // so items added to current will still be around for realtime get
                             // when tans overrides it

src/main/java/org/elasticsearch/index/gateway/IndexShardGatewayService.java

@@ -143,7 +143,7 @@ public class IndexShardGatewayService extends AbstractIndexShardComponent implem
                         indexShard.postRecovery("post recovery from gateway");
                     }
                     // refresh the shard
-                    indexShard.refresh("post_gateway", true);
+                    indexShard.refresh("post_gateway");
 
                     recoveryState.getTimer().time(System.currentTimeMillis() - recoveryState.getTimer().startTime());
                     recoveryState.setStage(RecoveryState.Stage.DONE);

src/main/java/org/elasticsearch/index/percolator/PercolatorQueriesRegistry.java

@@ -275,7 +275,7 @@ public class PercolatorQueriesRegistry extends AbstractIndexShardComponent imple
         }
 
         private int loadQueries(IndexShard shard) {
-            shard.refresh("percolator_load_queries", true);
+            shard.refresh("percolator_load_queries");
             // Maybe add a mode load? This isn't really a write. We need write b/c state=post_recovery
             try (Engine.Searcher searcher = shard.acquireSearcher("percolator_load_queries", true)) {
                 Query query = new ConstantScoreQuery(

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

@@ -226,10 +226,6 @@ public class IndexShard extends AbstractIndexShardComponent {
         return this.store;
     }
 
-    public Engine engine() {
-        return engineSafe();
-    }
-
     public Translog translog() {
         return translog;
     }
@@ -315,7 +311,7 @@ public class IndexShard extends AbstractIndexShardComponent {
             if (newRouting.state() == ShardRoutingState.STARTED || newRouting.state() == ShardRoutingState.RELOCATING) {
                 // we want to refresh *before* we move to internal STARTED state
                 try {
-                    engineSafe().refresh("cluster_state_started", true);
+                    engine().refresh("cluster_state_started");
                 } catch (Throwable t) {
                     logger.debug("failed to refresh due to move to cluster wide started", t);
                 }
@@ -410,7 +406,7 @@ public class IndexShard extends AbstractIndexShardComponent {
             if (logger.isTraceEnabled()) {
                 logger.trace("index [{}][{}]{}", create.type(), create.id(), create.docs());
             }
-            engineSafe().create(create);
+            engine().create(create);
             create.endTime(System.nanoTime());
         } catch (Throwable ex) {
             indexingService.postCreate(create, ex);
@@ -434,7 +430,7 @@ public class IndexShard extends AbstractIndexShardComponent {
             if (logger.isTraceEnabled()) {
                 logger.trace("index [{}][{}]{}", index.type(), index.id(), index.docs());
             }
-            engineSafe().index(index);
+            engine().index(index);
             index.endTime(System.nanoTime());
         } catch (Throwable ex) {
             indexingService.postIndex(index, ex);
@@ -457,7 +453,7 @@ public class IndexShard extends AbstractIndexShardComponent {
             if (logger.isTraceEnabled()) {
                 logger.trace("delete [{}]", delete.uid().text());
             }
-            engineSafe().delete(delete);
+            engine().delete(delete);
             delete.endTime(System.nanoTime());
         } catch (Throwable ex) {
             indexingService.postDelete(delete, ex);
@@ -485,23 +481,23 @@ public class IndexShard extends AbstractIndexShardComponent {
             logger.trace("delete_by_query [{}]", deleteByQuery.query());
         }
         deleteByQuery = indexingService.preDeleteByQuery(deleteByQuery);
-        engineSafe().delete(deleteByQuery);
+        engine().delete(deleteByQuery);
         deleteByQuery.endTime(System.nanoTime());
         indexingService.postDeleteByQuery(deleteByQuery);
     }
 
     public Engine.GetResult get(Engine.Get get) throws ElasticsearchException {
         readAllowed();
-        return engineSafe().get(get);
+        return engine().get(get);
     }
 
-    public void refresh(String source, boolean force) throws ElasticsearchException {
+    public void refresh(String source) throws ElasticsearchException {
         verifyNotClosed();
         if (logger.isTraceEnabled()) {
-            logger.trace("refresh with soruce: {} force: {}", source, force);
+            logger.trace("refresh with soruce: {}", source);
         }
         long time = System.nanoTime();
-        engineSafe().refresh(source, force);
+        engine().refresh(source);
         refreshMetric.inc(System.nanoTime() - time);
     }
 
@@ -549,7 +545,7 @@ public class IndexShard extends AbstractIndexShardComponent {
     }
 
     public SegmentsStats segmentStats() {
-        SegmentsStats segmentsStats = engineSafe().segmentsStats();
+        SegmentsStats segmentsStats = engine().segmentsStats();
         segmentsStats.addBitsetMemoryInBytes(shardBitsetFilterCache.getMemorySizeInBytes());
         return segmentsStats;
     }
@@ -611,7 +607,7 @@ public class IndexShard extends AbstractIndexShardComponent {
             logger.trace("flush with {}", request);
         }
         long time = System.nanoTime();
-        engineSafe().flush(request.full() ? Engine.FlushType.NEW_WRITER : Engine.FlushType.COMMIT_TRANSLOG, request.force(), request.waitIfOngoing());
+        engine().flush(request.full() ? Engine.FlushType.NEW_WRITER : Engine.FlushType.COMMIT_TRANSLOG, request.force(), request.waitIfOngoing());
         flushMetric.inc(System.nanoTime() - time);
     }
 
@@ -620,7 +616,7 @@ public class IndexShard extends AbstractIndexShardComponent {
         if (logger.isTraceEnabled()) {
             logger.trace("optimize with {}", optimize);
         }
-        engineSafe().forceMerge(optimize.flush(), optimize.waitForMerge(), optimize
+        engine().forceMerge(optimize.flush(), optimize.waitForMerge(), optimize
                 .maxNumSegments(), optimize.onlyExpungeDeletes(), optimize.upgrade());
     }
 
@@ -628,7 +624,7 @@ public class IndexShard extends AbstractIndexShardComponent {
         IndexShardState state = this.state; // one time volatile read
         // we allow snapshot on closed index shard, since we want to do one after we close the shard and before we close the engine
         if (state == IndexShardState.STARTED || state == IndexShardState.RELOCATED || state == IndexShardState.CLOSED) {
-            return engineSafe().snapshotIndex();
+            return engine().snapshotIndex();
         } else {
             throw new IllegalIndexShardStateException(shardId, state, "snapshot is not allowed");
         }
@@ -636,12 +632,12 @@ public class IndexShard extends AbstractIndexShardComponent {
 
     public void recover(Engine.RecoveryHandler recoveryHandler) throws EngineException {
         verifyStarted();
-        engineSafe().recover(recoveryHandler);
+        engine().recover(recoveryHandler);
     }
 
     public void failShard(String reason, Throwable e) {
         // fail the engine. This will cause this shard to also be removed from the node's index service.
-        engineSafe().failEngine(reason, e);
+        engine().failEngine(reason, e);
     }
 
     public Engine.Searcher acquireSearcher(String source) {
@@ -650,7 +646,7 @@ public class IndexShard extends AbstractIndexShardComponent {
 
     public Engine.Searcher acquireSearcher(String source, boolean searcherForWriteOperation) {
         readAllowed(searcherForWriteOperation);
-        return engineSafe().acquireSearcher(source);
+        return engine().acquireSearcher(source);
     }
 
     public void close(String reason) throws IOException {
@@ -740,11 +736,11 @@ public class IndexShard extends AbstractIndexShardComponent {
 
     public void performRecoveryFinalization(boolean withFlush) throws ElasticsearchException {
         if (withFlush) {
-            engineSafe().flush(Engine.FlushType.COMMIT_TRANSLOG, false, false);
+            engine().flush(Engine.FlushType.COMMIT_TRANSLOG, false, false);
         }
         // clear unreferenced files
         translog.clearUnreferenced();
-        engineSafe().refresh("recovery_finalization", true);
+        engine().refresh("recovery_finalization");
         synchronized (mutex) {
             changeState(IndexShardState.POST_RECOVERY, "post recovery");
         }
@@ -770,7 +766,7 @@ public class IndexShard extends AbstractIndexShardComponent {
                             source(create.source()).type(create.type()).id(create.id())
                                     .routing(create.routing()).parent(create.parent()).timestamp(create.timestamp()).ttl(create.ttl()),
                             create.version(), create.versionType().versionTypeForReplicationAndRecovery(), Engine.Operation.Origin.RECOVERY, true, false);
-                    engineSafe().create(engineCreate);
+                    engine().create(engineCreate);
                     indexOperation = engineCreate;
                     break;
                 case SAVE:
@@ -778,18 +774,18 @@ public class IndexShard extends AbstractIndexShardComponent {
                     Engine.Index engineIndex = prepareIndex(source(index.source()).type(index.type()).id(index.id())
                                     .routing(index.routing()).parent(index.parent()).timestamp(index.timestamp()).ttl(index.ttl()),
                             index.version(), index.versionType().versionTypeForReplicationAndRecovery(), Engine.Operation.Origin.RECOVERY, true);
-                    engineSafe().index(engineIndex);
+                    engine().index(engineIndex);
                     indexOperation = engineIndex;
                     break;
                 case DELETE:
                     Translog.Delete delete = (Translog.Delete) operation;
                     Uid uid = Uid.createUid(delete.uid().text());
-                    engineSafe().delete(new Engine.Delete(uid.type(), uid.id(), delete.uid(), delete.version(),
+                    engine().delete(new Engine.Delete(uid.type(), uid.id(), delete.uid(), delete.version(),
                             delete.versionType().versionTypeForReplicationAndRecovery(), Engine.Operation.Origin.RECOVERY, System.nanoTime(), false));
                     break;
                 case DELETE_BY_QUERY:
                     Translog.DeleteByQuery deleteByQuery = (Translog.DeleteByQuery) operation;
-                    engineSafe().delete(prepareDeleteByQuery(deleteByQuery.source(), deleteByQuery.filteringAliases(), Engine.Operation.Origin.RECOVERY, deleteByQuery.types()));
+                    engine().delete(prepareDeleteByQuery(deleteByQuery.source(), deleteByQuery.filteringAliases(), Engine.Operation.Origin.RECOVERY, deleteByQuery.types()));
                     break;
                 default:
                     throw new ElasticsearchIllegalStateException("No operation defined for [" + operation + "]");
@@ -905,13 +901,13 @@ public class IndexShard extends AbstractIndexShardComponent {
     }
 
     public void updateBufferSize(ByteSizeValue shardIndexingBufferSize, ByteSizeValue shardTranslogBufferSize) {
-        Engine engine = engineSafe();
+        Engine engine = engine();
         engine.updateIndexingBufferSize(shardIndexingBufferSize);
         translog().updateBuffer(shardTranslogBufferSize);
     }
 
     public void markAsInactive() {
-        Engine engine = engineSafe();
+        Engine engine = engine();
         engine.updateIndexingBufferSize(EngineConfig.INACTIVE_SHARD_INDEXING_BUFFER);
         translog().updateBuffer(Translog.INACTIVE_SHARD_TRANSLOG_BUFFER);
     }
@@ -954,8 +950,8 @@ public class IndexShard extends AbstractIndexShardComponent {
                 @Override
                 public void run() {
                     try {
-                        if (engineSafe().refreshNeeded()) {
-                            refresh("schedule", false);
+                        if (engine().refreshNeeded()) {
+                            refresh("schedule");
                         }
                     } catch (EngineClosedException e) {
                         // we are being closed, ignore
@@ -1036,7 +1032,7 @@ public class IndexShard extends AbstractIndexShardComponent {
         }
     }
 
-    private Engine engineSafe() {
+    public Engine engine() {
         Engine engine = this.currentEngineReference.get();
         if (engine == null) {
             throw new EngineClosedException(shardId);
@@ -1059,7 +1055,7 @@ public class IndexShard extends AbstractIndexShardComponent {
                     }
                 }
             } finally {
-                // close the engine all bets are off... don't use engineSafe() here it can throw an exception
+                // close the engine all bets are off... don't use engine() here it can throw an exception
                 IOUtils.closeWhileHandlingException(currentEngineReference.get());
             }
         }

src/main/java/org/elasticsearch/rest/action/admin/indices/refresh/RestRefreshAction.java

@@ -54,7 +54,6 @@ public class RestRefreshAction extends BaseRestHandler {
     public void handleRequest(final RestRequest request, final RestChannel channel, final Client client) {
         RefreshRequest refreshRequest = new RefreshRequest(Strings.splitStringByCommaToArray(request.param("index")));
         refreshRequest.listenerThreaded(false);
-        refreshRequest.force(request.paramAsBoolean("force", refreshRequest.force()));
         refreshRequest.indicesOptions(IndicesOptions.fromRequest(request, refreshRequest.indicesOptions()));
         client.admin().indices().refresh(refreshRequest, new RestBuilderListener<RefreshResponse>(channel) {
             @Override

src/test/java/org/elasticsearch/index/engine/internal/InternalEngineTests.java

@@ -265,7 +265,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
 
         ParsedDocument doc2 = testParsedDocument("2", "2", "test", null, -1, -1, testDocumentWithTextField(), B_2, false);
         engine.create(new Engine.Create(null, analyzer, newUid("2"), doc2));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(false);
         assertThat(segments.size(), equalTo(1));
@@ -298,7 +298,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
 
         ParsedDocument doc3 = testParsedDocument("3", "3", "test", null, -1, -1, testDocumentWithTextField(), B_3, false);
         engine.create(new Engine.Create(null, analyzer, newUid("3"), doc3));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(false);
         assertThat(segments.size(), equalTo(2));
@@ -324,7 +324,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
 
 
         engine.delete(new Engine.Delete("test", "1", newUid("1")));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(false);
         assertThat(segments.size(), equalTo(2));
@@ -345,7 +345,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         engineSettingsService.refreshSettings(ImmutableSettings.builder().put(EngineConfig.INDEX_COMPOUND_ON_FLUSH, true).build());
         ParsedDocument doc4 = testParsedDocument("4", "4", "test", null, -1, -1, testDocumentWithTextField(), B_3, false);
         engine.create(new Engine.Create(null, analyzer, newUid("4"), doc4));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(false);
         assertThat(segments.size(), equalTo(3));
@@ -376,7 +376,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, -1, -1, testDocumentWithTextField(), B_1, false);
         engine.create(new Engine.Create(null, analyzer, newUid("1"), doc));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(true);
         assertThat(segments.size(), equalTo(1));
@@ -384,10 +384,10 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         
         ParsedDocument doc2 = testParsedDocument("2", "2", "test", null, -1, -1, testDocumentWithTextField(), B_2, false);
         engine.create(new Engine.Create(null, analyzer, newUid("2"), doc2));
-        engine.refresh("test", false);
+        engine.refresh("test");
         ParsedDocument doc3 = testParsedDocument("3", "3", "test", null, -1, -1, testDocumentWithTextField(), B_3, false);
         engine.create(new Engine.Create(null, analyzer, newUid("3"), doc3));
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         segments = engine.segments(true);
         assertThat(segments.size(), equalTo(3));
@@ -528,7 +528,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         assertThat(getResult.exists(), equalTo(false));
         getResult.release();
         // refresh and it should be there
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         // now its there...
         searchResult = engine.acquireSearcher("test");
@@ -564,7 +564,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         getResult.release();
 
         // refresh and it should be updated
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         searchResult = engine.acquireSearcher("test");
         MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(1));
@@ -588,7 +588,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         getResult.release();
 
         // refresh and it should be deleted
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         searchResult = engine.acquireSearcher("test");
         MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(0));
@@ -610,7 +610,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         searchResult.close();
 
         // refresh and it should be there
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         // now its there...
         searchResult = engine.acquireSearcher("test");
@@ -644,7 +644,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         searchResult.close();
 
         // refresh and it should be updated
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         searchResult = engine.acquireSearcher("test");
         MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(1));
@@ -672,7 +672,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         searchResult.close();
 
         // refresh and it should be there
-        engine.refresh("test", false);
+        engine.refresh("test");
 
         // now its there...
         searchResult = engine.acquireSearcher("test");
@@ -682,7 +682,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
 
         // delete, refresh and do a new search, it should not be there
         engine.delete(new Engine.Delete("test", "1", newUid("1")));
-        engine.refresh("test", false);
+        engine.refresh("test");
         Engine.Searcher updateSearchResult = engine.acquireSearcher("test");
         MatcherAssert.assertThat(updateSearchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(0));
         updateSearchResult.close();
@@ -735,7 +735,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
 
             ParsedDocument doc2 = testParsedDocument("2", "2", "test", null, -1, -1, testDocumentWithTextField(), B_2, false);
             engine.create(new Engine.Create(null, analyzer, newUid("2"), doc2));
-            engine.refresh("foo", false);
+            engine.refresh("foo");
 
             searchResult = engine.acquireSearcher("test");
             MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(new TermQuery(new Term("value", "test")), 2));
@@ -1407,7 +1407,7 @@ public class InternalEngineTests extends ElasticsearchLuceneTestCase {
         Thread.sleep(1000);
 
         if (randomBoolean()) {
-            engine.refresh("test", false);
+            engine.refresh("test");
         }
 
         // Delete non-existent document