SERVER-48393 Exclude awaitable isMaster from serverStatus latency metrics

(cherry picked from commit 84033d0077d507491a6a80c2e1140bf6fd4055dc)

4 files changed, 24 insertions, 0 deletions

diff --git a/src/mongo/db/operation_context.h b/src/mongo/db/operation_context.h
index c5116e805b2..46626d843b7 100644
--- a/src/mongo/db/operation_context.h
+++ b/src/mongo/db/operation_context.h
@@ -267,6 +267,20 @@ public:
         return _writesAreReplicated;
     }
 
+    /**
+     * Returns true if operations' durations should be added to serverStatus latency metrics.
+     */
+    bool shouldIncrementLatencyStats() const {
+        return _shouldIncrementLatencyStats;
+    }
+
+    /**
+     * Sets the shouldIncrementLatencyStats flag.
+     */
+    void setShouldIncrementLatencyStats(bool shouldIncrementLatencyStats) {
+        _shouldIncrementLatencyStats = shouldIncrementLatencyStats;
+    }
+
     void markKillOnClientDisconnect();
 
     /**
@@ -568,6 +582,7 @@ private:
     Timer _elapsedTime;
 
     bool _writesAreReplicated = true;
+    bool _shouldIncrementLatencyStats = true;
     bool _shouldParticipateInFlowControl = true;
     bool _inMultiDocumentTransaction = false;
     bool _isStartingMultiDocumentTransaction = false;
diff --git a/src/mongo/db/repl/replication_info.cpp b/src/mongo/db/repl/replication_info.cpp
index e105a3469d9..617ac34bfc2 100644
--- a/src/mongo/db/repl/replication_info.cpp
+++ b/src/mongo/db/repl/replication_info.cpp
@@ -462,6 +462,9 @@ public:
             uassert(31373, "maxAwaitTimeMS must be a non-negative integer", *maxAwaitTimeMS >= 0);
 
             LOGV2_DEBUG(23904, 3, "Using maxAwaitTimeMS for awaitable isMaster protocol.");
+
+            // Awaitable isMaster commands have high latency by design.
+            opCtx->setShouldIncrementLatencyStats(false);
         } else {
             uassert(31368,
                     (topologyVersionElement
diff --git a/src/mongo/db/stats/top.cpp b/src/mongo/db/stats/top.cpp
index e445515cf4b..1674fe394d6 100644
--- a/src/mongo/db/stats/top.cpp
+++ b/src/mongo/db/stats/top.cpp
@@ -200,6 +200,9 @@ void Top::appendLatencyStats(const NamespaceString& nss,
 void Top::incrementGlobalLatencyStats(OperationContext* opCtx,
                                       uint64_t latency,
                                       Command::ReadWriteType readWriteType) {
+    if (!opCtx->shouldIncrementLatencyStats())
+        return;
+
     stdx::lock_guard<SimpleMutex> guard(_lock);
     _incrementHistogram(opCtx, latency, &_globalHistogramStats, readWriteType);
 }
diff --git a/src/mongo/s/commands/cluster_is_master_cmd.cpp b/src/mongo/s/commands/cluster_is_master_cmd.cpp
index 1b0af958848..a71c0c28ef2 100644
--- a/src/mongo/s/commands/cluster_is_master_cmd.cpp
+++ b/src/mongo/s/commands/cluster_is_master_cmd.cpp
@@ -147,6 +147,9 @@ public:
 
             LOGV2_DEBUG(23871, 3, "Using maxAwaitTimeMS for awaitable isMaster protocol.");
 
+            // Awaitable isMaster commands have high latency by design. Ignore them.
+            opCtx->setShouldIncrementLatencyStats(false);
+
             if (clientTopologyVersion->getProcessId() == mongosTopologyVersion.getProcessId()) {
                 uassert(51761,
                         str::stream()