SERVER-35157 Add transactions latency tracking to OperationLatencyHistogram

4 files changed, 12 insertions, 5 deletions

diff --git a/src/mongo/db/commands.h b/src/mongo/db/commands.h
index a767c8f60c8..966a0d640c7 100644
--- a/src/mongo/db/commands.h
+++ b/src/mongo/db/commands.h
@@ -370,12 +370,12 @@ public:
     }
 
     /**
-     * Returns whether this operation is a read, write, or command.
+     * Returns whether this operation is a read, write, command, or multi-document transaction.
      *
      * Commands which implement database read or write logic should override this to return kRead
      * or kWrite as appropriate.
      */
-    enum class ReadWriteType { kCommand, kRead, kWrite };
+    enum class ReadWriteType { kCommand, kRead, kWrite, kTransaction };
     virtual ReadWriteType getReadWriteType() const {
         return ReadWriteType::kCommand;
     }
diff --git a/src/mongo/db/stats/operation_latency_histogram.cpp b/src/mongo/db/stats/operation_latency_histogram.cpp
index 74a1f462760..be406c860f4 100644
--- a/src/mongo/db/stats/operation_latency_histogram.cpp
+++ b/src/mongo/db/stats/operation_latency_histogram.cpp
@@ -118,6 +118,7 @@ void OperationLatencyHistogram::append(bool includeHistograms, BSONObjBuilder* b
     _append(_reads, "reads", includeHistograms, builder);
     _append(_writes, "writes", includeHistograms, builder);
     _append(_commands, "commands", includeHistograms, builder);
+    _append(_transactions, "transactions", includeHistograms, builder);
 }
 
 // Computes the log base 2 of value, and checks for cases of split buckets.
@@ -165,6 +166,9 @@ void OperationLatencyHistogram::increment(uint64_t latency, Command::ReadWriteTy
         case Command::ReadWriteType::kCommand:
             _incrementData(latency, bucket, &_commands);
             break;
+        case Command::ReadWriteType::kTransaction:
+            _incrementData(latency, bucket, &_transactions);
+            break;
         default:
             MONGO_UNREACHABLE;
     }
diff --git a/src/mongo/db/stats/operation_latency_histogram.h b/src/mongo/db/stats/operation_latency_histogram.h
index 3d6e753ca49..e7652c7383f 100644
--- a/src/mongo/db/stats/operation_latency_histogram.h
+++ b/src/mongo/db/stats/operation_latency_histogram.h
@@ -36,7 +36,8 @@ namespace mongo {
 class BSONObjBuilder;
 
 /**
- * Stores statistics for latencies of read, write, and command operations.
+ * Stores statistics for latencies of read, write, command, and multi-document transaction
+ * operations.
  *
  * Note: This class is not thread-safe.
  */
@@ -53,7 +54,7 @@ public:
     void increment(uint64_t latency, Command::ReadWriteType type);
 
     /**
-     * Appends the three histograms with latency totals and operation counts.
+     * Appends the four histograms with latency totals and operation counts.
      */
     void append(bool includeHistograms, BSONObjBuilder* builder) const;
 
@@ -75,6 +76,6 @@ private:
 
     void _incrementData(uint64_t latency, int bucket, HistogramData* data);
 
-    HistogramData _reads, _writes, _commands;
+    HistogramData _reads, _writes, _commands, _transactions;
 };
 }  // namespace mongo
diff --git a/src/mongo/db/stats/operation_latency_histogram_test.cpp b/src/mongo/db/stats/operation_latency_histogram_test.cpp
index 9a1e0b05328..03f4ffb2968 100644
--- a/src/mongo/db/stats/operation_latency_histogram_test.cpp
+++ b/src/mongo/db/stats/operation_latency_histogram_test.cpp
@@ -52,6 +52,7 @@ TEST(OperationLatencyHistogram, EnsureIncrementsStored) {
         hist.increment(i, Command::ReadWriteType::kRead);
         hist.increment(i, Command::ReadWriteType::kWrite);
         hist.increment(i, Command::ReadWriteType::kCommand);
+        hist.increment(i, Command::ReadWriteType::kTransaction);
     }
     BSONObjBuilder outBuilder;
     hist.append(false, &outBuilder);
@@ -59,6 +60,7 @@ TEST(OperationLatencyHistogram, EnsureIncrementsStored) {
     ASSERT_EQUALS(out["reads"]["ops"].Long(), kMaxBuckets);
     ASSERT_EQUALS(out["writes"]["ops"].Long(), kMaxBuckets);
     ASSERT_EQUALS(out["commands"]["ops"].Long(), kMaxBuckets);
+    ASSERT_EQUALS(out["transactions"]["ops"].Long(), kMaxBuckets);
 }
 
 TEST(OperationLatencyHistogram, CheckBucketCountsAndTotalLatency) {