diff --git a/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java b/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
index cdc83fa8ffc..2d186ade638 100644
--- a/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
+++ b/core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java
@@ -543,7 +543,7 @@ public class InternalEngine extends Engine {
                 refresh("write indexing buffer");
             } else {
                 // Most of our heap is used by the indexing buffer, so we do a cheaper (just writes segments, doesn't open a new searcher) IW.flush:
-                logger.debug("use flush to write indexing buffer (heap size=[{}]) since version map is small (heap size=[{}])",
+                logger.debug("use IndexWriter.flush to write indexing buffer (heap size=[{}]) since version map is small (heap size=[{}])",
                              new ByteSizeValue(indexingBufferBytes), new ByteSizeValue(versionMapBytes));
                 indexWriter.flush();
             }
diff --git a/core/src/main/java/org/elasticsearch/indices/memory/IndexingMemoryController.java b/core/src/main/java/org/elasticsearch/indices/memory/IndexingMemoryController.java
index 56166134df5..bce4f61f800 100644
--- a/core/src/main/java/org/elasticsearch/indices/memory/IndexingMemoryController.java
+++ b/core/src/main/java/org/elasticsearch/indices/memory/IndexingMemoryController.java
@@ -301,8 +301,6 @@ public class IndexingMemoryController extends AbstractLifecycleComponent<Indexin
 
             if (totalBytesUsed > indexingBuffer.bytes()) {
                 // OK we are now over-budget; fill the priority queue and ask largest shard(s) to refresh:
-                logger.debug("now write some indexing buffers: total indexing heap bytes used [{}] vs {} [{}], currently writing bytes [{}]",
-                             new ByteSizeValue(totalBytesUsed), INDEX_BUFFER_SIZE_SETTING, indexingBuffer, new ByteSizeValue(totalBytesWriting));
                 PriorityQueue<ShardAndBytesUsed> queue = new PriorityQueue<>();
 
                 for (IndexShard shard : availableShards()) {
@@ -333,6 +331,9 @@ public class IndexingMemoryController extends AbstractLifecycleComponent<Indexin
                     }
                 }
 
+                logger.debug("now write some indexing buffers: total indexing heap bytes used [{}] vs {} [{}], currently writing bytes [{}], [{}] shards with non-zero indexing buffer",
+                             new ByteSizeValue(totalBytesUsed), INDEX_BUFFER_SIZE_SETTING, indexingBuffer, new ByteSizeValue(totalBytesWriting), queue.size());
+
                 while (totalBytesUsed > indexingBuffer.bytes() && queue.isEmpty() == false) {
                     ShardAndBytesUsed largest = queue.poll();
                     logger.debug("write indexing buffer to disk for shard [{}] to free up its [{}] indexing buffer", largest.shard.shardId(), new ByteSizeValue(largest.bytesUsed));