Track in-progress indexing operations (#65996)

Currently, our indexing pressure metrics only track the number of "bytes"
related to in-progress indexing requests. This commit introduces tracking of
the number of operations. Building out this metrics will add more information
for future monitoring and back-pressure.

server/src/main/java/org/elasticsearch/action/bulk/TransportBulkAction.java

@@ -159,9 +159,10 @@ public static IndexRequest getIndexWriteRequest(DocWriteRequest<?> docWriteReque
 
     @Override
     protected void doExecute(Task task, BulkRequest bulkRequest, ActionListener<BulkResponse> listener) {
+        final int indexingOps = bulkRequest.numberOfActions();
         final long indexingBytes = bulkRequest.ramBytesUsed();
         final boolean isOnlySystem = isOnlySystem(bulkRequest, clusterService.state().metadata().getIndicesLookup(), systemIndices);
-        final Releasable releasable = indexingPressure.markCoordinatingOperationStarted(indexingBytes, isOnlySystem);
+        final Releasable releasable = indexingPressure.markCoordinatingOperationStarted(indexingOps, indexingBytes, isOnlySystem);
         final ActionListener<BulkResponse> releasingListener = ActionListener.runBefore(listener, releasable::close);
         final String executorName = isOnlySystem ? Names.SYSTEM_WRITE : Names.WRITE;
         try {

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

@@ -155,6 +155,11 @@ protected long primaryOperationSize(BulkShardRequest request) {
         return request.ramBytesUsed();
     }
 
+    @Override
+    protected int primaryOperationCount(BulkShardRequest request) {
+        return request.items().length;
+    }
+
     public static void performOnPrimary(
         BulkShardRequest request,
         IndexShard primary,
@@ -439,6 +444,11 @@ protected long replicaOperationSize(BulkShardRequest request) {
         return request.ramBytesUsed();
     }
 
+    @Override
+    protected int replicaOperationCount(BulkShardRequest request) {
+        return request.items().length;
+    }
+
     public static Translog.Location performOnReplica(BulkShardRequest request, IndexShard replica) throws Exception {
         Translog.Location location = null;
         for (int i = 0; i < request.items().length; i++) {

server/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java

@@ -113,6 +113,11 @@ protected long primaryOperationSize(ResyncReplicationRequest request) {
         return Stream.of(request.getOperations()).mapToLong(Translog.Operation::estimateSize).sum();
     }
 
+    @Override
+    protected int primaryOperationCount(ResyncReplicationRequest request) {
+        return request.getOperations().length;
+    }
+
     public static ResyncReplicationRequest performOnPrimary(ResyncReplicationRequest request) {
         return request;
     }
@@ -131,6 +136,11 @@ protected long replicaOperationSize(ResyncReplicationRequest request) {
         return Stream.of(request.getOperations()).mapToLong(Translog.Operation::estimateSize).sum();
     }
 
+    @Override
+    protected int replicaOperationCount(ResyncReplicationRequest request) {
+        return request.getOperations().length;
+    }
+
     public static Translog.Location performOnReplica(ResyncReplicationRequest request, IndexShard replica) throws Exception {
         Translog.Location location = null;
         /*

server/src/main/java/org/elasticsearch/action/support/replication/TransportWriteAction.java

@@ -88,7 +88,7 @@ protected String executor(IndexShard shard) {
 
     @Override
     protected Releasable checkOperationLimits(Request request) {
-        return indexingPressure.markPrimaryOperationStarted(primaryOperationSize(request), force(request));
+        return indexingPressure.markPrimaryOperationStarted(primaryOperationCount(request), primaryOperationSize(request), force(request));
     }
 
     protected boolean force(ReplicatedWriteRequest<?> request) {
@@ -106,31 +106,41 @@ protected Releasable checkPrimaryLimits(Request request, boolean rerouteWasLocal
             // If this primary request was received from a local reroute initiated by the node client, we
             // must mark a new primary operation local to the coordinating node.
             if (localRerouteInitiatedByNodeClient) {
-                return indexingPressure.markPrimaryOperationLocalToCoordinatingNodeStarted(primaryOperationSize(request));
+                return indexingPressure.markPrimaryOperationLocalToCoordinatingNodeStarted(primaryOperationCount(request),
+                    primaryOperationSize(request));
             } else {
                 return () -> {};
             }
         } else {
             // If this primary request was received directly from the network, we must mark a new primary
             // operation. This happens if the write action skips the reroute step (ex: rsync) or during
             // primary delegation, after the primary relocation hand-off.
-            return indexingPressure.markPrimaryOperationStarted(primaryOperationSize(request), force(request));
+            return indexingPressure.markPrimaryOperationStarted(primaryOperationCount(request), primaryOperationSize(request),
+                force(request));
         }
     }
 
     protected long primaryOperationSize(Request request) {
         return 0;
     }
 
+    protected int primaryOperationCount(Request request) {
+        return 0;
+    }
+
     @Override
     protected Releasable checkReplicaLimits(ReplicaRequest request) {
-        return indexingPressure.markReplicaOperationStarted(replicaOperationSize(request), force(request));
+        return indexingPressure.markReplicaOperationStarted(replicaOperationCount(request), replicaOperationSize(request), force(request));
     }
 
     protected long replicaOperationSize(ReplicaRequest request) {
         return 0;
     }
 
+    protected int replicaOperationCount(ReplicaRequest request) {
+        return 0;
+    }
+
     /** Syncs operation result to the translog or throws a shard not available failure */
     protected static Location syncOperationResultOrThrow(final Engine.Result operationResult,
                                                          final Location currentLocation) throws Exception {

server/src/main/java/org/elasticsearch/index/IndexingPressure.java

@@ -38,11 +38,19 @@ public class IndexingPressure {
     private final AtomicLong currentPrimaryBytes = new AtomicLong(0);
     private final AtomicLong currentReplicaBytes = new AtomicLong(0);
 
+    private final AtomicLong currentCoordinatingOps = new AtomicLong(0);
+    private final AtomicLong currentPrimaryOps = new AtomicLong(0);
+    private final AtomicLong currentReplicaOps = new AtomicLong(0);
+
     private final AtomicLong totalCombinedCoordinatingAndPrimaryBytes = new AtomicLong(0);
     private final AtomicLong totalCoordinatingBytes = new AtomicLong(0);
     private final AtomicLong totalPrimaryBytes = new AtomicLong(0);
     private final AtomicLong totalReplicaBytes = new AtomicLong(0);
 
+    private final AtomicLong totalCoordinatingOps = new AtomicLong(0);
+    private final AtomicLong totalPrimaryOps = new AtomicLong(0);
+    private final AtomicLong totalReplicaOps = new AtomicLong(0);
+
     private final AtomicLong coordinatingRejections = new AtomicLong(0);
     private final AtomicLong primaryRejections = new AtomicLong(0);
     private final AtomicLong replicaRejections = new AtomicLong(0);
@@ -55,7 +63,7 @@ public IndexingPressure(Settings settings) {
         this.replicaLimits = (long) (this.primaryAndCoordinatingLimits * 1.5);
     }
 
-    public Releasable markCoordinatingOperationStarted(long bytes, boolean forceExecution) {
+    public Releasable markCoordinatingOperationStarted(int operations, long bytes, boolean forceExecution) {
         long combinedBytes = this.currentCombinedCoordinatingAndPrimaryBytes.addAndGet(bytes);
         long replicaWriteBytes = this.currentReplicaBytes.get();
         long totalBytes = combinedBytes + replicaWriteBytes;
@@ -72,21 +80,29 @@ public Releasable markCoordinatingOperationStarted(long bytes, boolean forceExec
                 "max_coordinating_and_primary_bytes=" + primaryAndCoordinatingLimits + "]", false);
         }
         currentCoordinatingBytes.getAndAdd(bytes);
+        currentCoordinatingOps.getAndAdd(operations);
         totalCombinedCoordinatingAndPrimaryBytes.getAndAdd(bytes);
         totalCoordinatingBytes.getAndAdd(bytes);
+        totalCoordinatingOps.getAndAdd(operations);
         return () -> {
             this.currentCombinedCoordinatingAndPrimaryBytes.getAndAdd(-bytes);
             this.currentCoordinatingBytes.getAndAdd(-bytes);
+            this.currentCoordinatingOps.getAndAdd(-operations);
         };
     }
 
-    public Releasable markPrimaryOperationLocalToCoordinatingNodeStarted(long bytes) {
+    public Releasable markPrimaryOperationLocalToCoordinatingNodeStarted(int operations, long bytes) {
         currentPrimaryBytes.getAndAdd(bytes);
+        currentPrimaryOps.getAndAdd(operations);
         totalPrimaryBytes.getAndAdd(bytes);
-        return () -> this.currentPrimaryBytes.getAndAdd(-bytes);
+        totalPrimaryOps.getAndAdd(operations);
+        return () -> {
+            this.currentPrimaryBytes.getAndAdd(-bytes);
+            this.currentPrimaryOps.getAndAdd(-operations);
+        };
     }
 
-    public Releasable markPrimaryOperationStarted(long bytes, boolean forceExecution) {
+    public Releasable markPrimaryOperationStarted(int operations, long bytes, boolean forceExecution) {
         long combinedBytes = this.currentCombinedCoordinatingAndPrimaryBytes.addAndGet(bytes);
         long replicaWriteBytes = this.currentReplicaBytes.get();
         long totalBytes = combinedBytes + replicaWriteBytes;
@@ -103,15 +119,18 @@ public Releasable markPrimaryOperationStarted(long bytes, boolean forceExecution
                 "max_coordinating_and_primary_bytes=" + primaryAndCoordinatingLimits + "]", false);
         }
         currentPrimaryBytes.getAndAdd(bytes);
+        currentPrimaryOps.getAndAdd(operations);
         totalCombinedCoordinatingAndPrimaryBytes.getAndAdd(bytes);
         totalPrimaryBytes.getAndAdd(bytes);
+        totalPrimaryOps.getAndAdd(operations);
         return () -> {
             this.currentCombinedCoordinatingAndPrimaryBytes.getAndAdd(-bytes);
             this.currentPrimaryBytes.getAndAdd(-bytes);
+            this.currentPrimaryOps.getAndAdd(-operations);
         };
     }
 
-    public Releasable markReplicaOperationStarted(long bytes, boolean forceExecution) {
+    public Releasable markReplicaOperationStarted(int operations, long bytes, boolean forceExecution) {
         long replicaWriteBytes = this.currentReplicaBytes.addAndGet(bytes);
         if (forceExecution == false && replicaWriteBytes > replicaLimits) {
             long replicaBytesWithoutOperation = replicaWriteBytes - bytes;
@@ -122,30 +141,20 @@ public Releasable markReplicaOperationStarted(long bytes, boolean forceExecution
                 "replica_operation_bytes=" + bytes + ", " +
                 "max_replica_bytes=" + replicaLimits + "]", false);
         }
+        currentReplicaOps.getAndAdd(operations);
         totalReplicaBytes.getAndAdd(bytes);
-        return () -> this.currentReplicaBytes.getAndAdd(-bytes);
-    }
-
-    public long getCurrentCombinedCoordinatingAndPrimaryBytes() {
-        return currentCombinedCoordinatingAndPrimaryBytes.get();
-    }
-
-    public long getCurrentCoordinatingBytes() {
-        return currentCoordinatingBytes.get();
-    }
-
-    public long getCurrentPrimaryBytes() {
-        return currentPrimaryBytes.get();
-    }
-
-    public long getCurrentReplicaBytes() {
-        return currentReplicaBytes.get();
+        totalReplicaOps.getAndAdd(operations);
+        return () -> {
+            this.currentReplicaBytes.getAndAdd(-bytes);
+            this.currentReplicaOps.getAndAdd(-operations);
+        };
     }
 
     public IndexingPressureStats stats() {
         return new IndexingPressureStats(totalCombinedCoordinatingAndPrimaryBytes.get(), totalCoordinatingBytes.get(),
             totalPrimaryBytes.get(), totalReplicaBytes.get(), currentCombinedCoordinatingAndPrimaryBytes.get(),
             currentCoordinatingBytes.get(), currentPrimaryBytes.get(), currentReplicaBytes.get(), coordinatingRejections.get(),
-            primaryRejections.get(), replicaRejections.get(), primaryAndCoordinatingLimits);
+            primaryRejections.get(), replicaRejections.get(), primaryAndCoordinatingLimits, totalCoordinatingOps.get(),
+            totalPrimaryOps.get(), totalReplicaOps.get(), currentCoordinatingOps.get(), currentPrimaryOps.get(), currentReplicaOps.get());
     }
 }

server/src/main/java/org/elasticsearch/index/stats/IndexingPressureStats.java

@@ -46,6 +46,14 @@ public class IndexingPressureStats implements Writeable, ToXContentFragment {
     private final long replicaRejections;
     private final long memoryLimit;
 
+    // These fields will be used for additional back-pressure and metrics in the future
+    private final long totalCoordinatingOps;
+    private final long totalPrimaryOps;
+    private final long totalReplicaOps;
+    private final long currentCoordinatingOps;
+    private final long currentPrimaryOps;
+    private final long currentReplicaOps;
+
     public IndexingPressureStats(StreamInput in) throws IOException {
         totalCombinedCoordinatingAndPrimaryBytes = in.readVLong();
         totalCoordinatingBytes = in.readVLong();
@@ -66,12 +74,21 @@ public IndexingPressureStats(StreamInput in) throws IOException {
         } else {
             memoryLimit = -1L;
         }
+
+        // These are not currently propagated across the network yet
+        this.totalCoordinatingOps = 0;
+        this.totalPrimaryOps = 0;
+        this.totalReplicaOps = 0;
+        this.currentCoordinatingOps = 0;
+        this.currentPrimaryOps = 0;
+        this.currentReplicaOps = 0;
     }
 
     public IndexingPressureStats(long totalCombinedCoordinatingAndPrimaryBytes, long totalCoordinatingBytes, long totalPrimaryBytes,
                                  long totalReplicaBytes, long currentCombinedCoordinatingAndPrimaryBytes, long currentCoordinatingBytes,
                                  long currentPrimaryBytes, long currentReplicaBytes, long coordinatingRejections, long primaryRejections,
-                                 long replicaRejections, long memoryLimit) {
+                                 long replicaRejections, long memoryLimit, long totalCoordinatingOps, long totalPrimaryOps,
+                                 long totalReplicaOps, long currentCoordinatingOps, long currentPrimaryOps, long currentReplicaOps) {
         this.totalCombinedCoordinatingAndPrimaryBytes = totalCombinedCoordinatingAndPrimaryBytes;
         this.totalCoordinatingBytes = totalCoordinatingBytes;
         this.totalPrimaryBytes = totalPrimaryBytes;
@@ -84,6 +101,13 @@ public IndexingPressureStats(long totalCombinedCoordinatingAndPrimaryBytes, long
         this.primaryRejections = primaryRejections;
         this.replicaRejections = replicaRejections;
         this.memoryLimit = memoryLimit;
+
+        this.totalCoordinatingOps = totalCoordinatingOps;
+        this.totalPrimaryOps = totalPrimaryOps;
+        this.totalReplicaOps = totalReplicaOps;
+        this.currentCoordinatingOps = currentCoordinatingOps;
+        this.currentPrimaryOps = currentPrimaryOps;
+        this.currentReplicaOps = currentReplicaOps;
     }
 
     @Override
@@ -151,6 +175,30 @@ public long getReplicaRejections() {
         return replicaRejections;
     }
 
+    public long getTotalCoordinatingOps() {
+        return totalCoordinatingOps;
+    }
+
+    public long getTotalPrimaryOps() {
+        return totalPrimaryOps;
+    }
+
+    public long getTotalReplicaOps() {
+        return totalReplicaOps;
+    }
+
+    public long getCurrentCoordinatingOps() {
+        return currentCoordinatingOps;
+    }
+
+    public long getCurrentPrimaryOps() {
+        return currentPrimaryOps;
+    }
+
+    public long getCurrentReplicaOps() {
+        return currentReplicaOps;
+    }
+
     private static final String COMBINED = "combined_coordinating_and_primary";
     private static final String COMBINED_IN_BYTES = "combined_coordinating_and_primary_in_bytes";
     private static final String COORDINATING = "coordinating";