SERVER-34422-ThreadMetrics: ServerStatus now returns the number of active client operations

(cherry picked from commit cdf319123d8e5d3cd169e2a11aec6aea0b951bf1)

3 files changed, 22 insertions, 0 deletions

diff --git a/src/mongo/db/service_context.cpp b/src/mongo/db/service_context.cpp
index d1089916327..0930c9c9a61 100644
--- a/src/mongo/db/service_context.cpp
+++ b/src/mongo/db/service_context.cpp
@@ -59,6 +59,8 @@ using ConstructorActionList = stdx::list<ServiceContext::ConstructorDestructorAc
 
 ServiceContext* globalServiceContext = nullptr;
 
+AtomicWord<int> _numCurrentOps{0};
+
 }  // namespace
 
 bool hasGlobalServiceContext() {
@@ -239,6 +241,10 @@ void ServiceContext::ClientDeleter::operator()(Client* client) const {
 
 ServiceContext::UniqueOperationContext ServiceContext::makeOperationContext(Client* client) {
     auto opCtx = std::make_unique<OperationContext>(client, _nextOpId.fetchAndAdd(1));
+    if (client && client->session()) {
+        _numCurrentOps.addAndFetch(1);
+    }
+
     onCreate(opCtx.get(), _clientObservers);
     if (!opCtx->lockState()) {
         opCtx->setLockState(std::make_unique<LockerNoop>());
@@ -256,6 +262,9 @@ ServiceContext::UniqueOperationContext ServiceContext::makeOperationContext(Clie
 
 void ServiceContext::OperationContextDeleter::operator()(OperationContext* opCtx) const {
     auto client = opCtx->getClient();
+    if (client && client->session()) {
+        _numCurrentOps.subtractAndFetch(1);
+    }
     auto service = client->getServiceContext();
     {
         stdx::lock_guard<Client> lk(*client);
@@ -356,6 +365,10 @@ void ServiceContext::notifyStartupComplete() {
     _startupCompleteCondVar.notify_all();
 }
 
+int ServiceContext::getActiveClientOperations() {
+    return _numCurrentOps.load();
+}
+
 namespace {
 
 /**
diff --git a/src/mongo/db/service_context.h b/src/mongo/db/service_context.h
index 96e965d53c7..55b0545171e 100644
--- a/src/mongo/db/service_context.h
+++ b/src/mongo/db/service_context.h
@@ -432,6 +432,11 @@ public:
      */
     void notifyStartupComplete();
 
+    /*
+     * Returns the number of active client operations
+     */
+    int getActiveClientOperations();
+
     /**
      * Set the OpObserver.
      */
diff --git a/src/mongo/transport/service_entry_point_impl.cpp b/src/mongo/transport/service_entry_point_impl.cpp
index a4935cb0fdc..2dc1562ffdb 100644
--- a/src/mongo/transport/service_entry_point_impl.cpp
+++ b/src/mongo/transport/service_entry_point_impl.cpp
@@ -37,6 +37,7 @@
 #include <vector>
 
 #include "mongo/db/auth/restriction_environment.h"
+#include "mongo/db/service_context.h"
 #include "mongo/transport/service_state_machine.h"
 #include "mongo/transport/session.h"
 #include "mongo/util/log.h"
@@ -244,6 +245,9 @@ void ServiceEntryPointImpl::appendStats(BSONObjBuilder* bob) const {
     bob->append("current", static_cast<int>(sessionCount));
     bob->append("available", static_cast<int>(_maxNumConnections - sessionCount));
     bob->append("totalCreated", static_cast<int>(_createdConnections.load()));
+    if (auto sc = getGlobalServiceContext()) {
+        bob->append("active", static_cast<int>(sc->getActiveClientOperations()));
+    }
 
     if (_adminInternalPool) {
         BSONObjBuilder section(bob->subobjStart("adminConnections"));