review comments

Author: ankikuma

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

@@ -172,13 +172,14 @@ void writeIndexingBuffersTime(long took) {
     }
 
     static class StatsHolder {
-        private final MeanMetric indexMetric = new MeanMetric(); // Used for the count and total 'took' time (in ns) of index operations
-        private final LongAdder writeIndexingBufferTime = new LongAdder();
+        // Used for the count and total 'took' time (in ns) of index operations
+        private final MeanMetric indexMetric = new MeanMetric();
         // Used for the total time taken to flush indexing buffers to disk (on indexing threads) (in ns)
+        private final LongAdder writeIndexingBufferTime = new LongAdder();
+        // An EWMR of the total 'took' time of index operations (indexMetric) plus the writeIndexingBufferTime (in ns)
         private final ExponentiallyWeightedMovingRate recentIndexMetric;
-        // An EWMR of the total 'took' time of index operations (in ns) plus the writeIndexingBufferTime
-        private final AtomicReference<Double> peakIndexMetric;
         // The peak value of the EWMR (recentIndexMetric) observed in any stats() call
+        private final AtomicReference<Double> peakIndexMetric;
         private final MeanMetric deleteMetric = new MeanMetric();
         private final CounterMetric indexCurrent = new CounterMetric();
         private final CounterMetric indexFailed = new CounterMetric();
@@ -208,8 +209,9 @@ IndexingStats.Stats stats(
         ) {
             final long totalIndexingTimeInNanos = indexMetric.sum();
             final long totalIndexingTimeSinceShardStartedInNanos = totalIndexingTimeInNanos - indexingTimeBeforeShardStartedInNanos;
-            final long totalIndexingLoadInNanos = totalIndexingTimeInNanos + writeIndexingBufferTime.sum();
-            final long totalIndexingLoadSinceShardStartedInNanos = totalIndexingLoadInNanos - indexingLoadBeforeShardStartedInNanos;
+            // This is different from indexing time as it also includes the
+            final long totalIndexingExecutionTimeInNanos = totalIndexingTimeInNanos + writeIndexingBufferTime.sum();
+            final long totalIndexingExecutionTimeSinceShardStartedInNanos = totalIndexingExecutionTimeInNanos - indexingLoadBeforeShardStartedInNanos;
             final double recentIndexingLoadSinceShardStarted = recentIndexMetric.calculateRateSince(
                 currentTimeInNanos,
                 recentIndexMetric.getRate(currentTimeInNanos),
@@ -243,7 +245,7 @@ IndexingStats.Stats stats(
                 isThrottled,
                 TimeUnit.MILLISECONDS.toMillis(currentThrottleMillis),
                 totalIndexingTimeSinceShardStartedInNanos,
-                totalIndexingLoadSinceShardStartedInNanos,
+                totalIndexingExecutionTimeSinceShardStartedInNanos,
                 timeSinceShardStartedInNanos,
                 recentIndexingLoadSinceShardStarted,
                 peakIndexingLoad

server/src/main/java/org/elasticsearch/indices/IndexingMemoryController.java

@@ -205,16 +205,14 @@ protected void enqueueWriteIndexingBuffer(IndexShard shard) {
      */
     private boolean writePendingIndexingBuffers() {
         boolean wrotePendingIndexingBuffer = false;
-        long startTime;
-        long took;
         for (IndexShard shard = pendingWriteIndexingBufferQueue.pollFirst(); shard != null; shard = pendingWriteIndexingBufferQueue
             .pollFirst()) {
             // Remove the shard from the set first, so that multiple threads can run writeIndexingBuffer concurrently on the same shard.
             pendingWriteIndexingBufferSet.remove(shard);
             // Calculate the time taken to write the indexing buffers so it can be accounted for in the index write load
-            startTime = System.nanoTime();
+            long startTime = System.nanoTime();
             shard.writeIndexingBuffer();
-            took = System.nanoTime() - startTime;
+            long took = System.nanoTime() - startTime;
             shard.writeIndexBuffersOnIndexThreads(took);
             wrotePendingIndexingBuffer = true;
         }