SERVER-74569 Start with number of CPU cores for throughput probing

5 files changed, 30 insertions, 5 deletions

diff --git a/src/mongo/db/concurrency/d_concurrency_test.cpp b/src/mongo/db/concurrency/d_concurrency_test.cpp
index ba3a3ada084..dc5790cb65f 100644
--- a/src/mongo/db/concurrency/d_concurrency_test.cpp
+++ b/src/mongo/db/concurrency/d_concurrency_test.cpp
@@ -37,6 +37,7 @@
 #include "mongo/db/concurrency/replication_state_transition_lock_guard.h"
 #include "mongo/db/service_context_d_test_fixture.h"
 #include "mongo/db/storage/recovery_unit_noop.h"
+#include "mongo/db/storage/storage_engine_parameters_gen.h"
 #include "mongo/db/storage/ticketholder_manager.h"
 #include "mongo/logv2/log.h"
 #include "mongo/stdx/future.h"
@@ -71,6 +72,7 @@ class UseReaderWriterGlobalThrottling {
 public:
     explicit UseReaderWriterGlobalThrottling(ServiceContext* svcCtx, int numTickets)
         : _svcCtx(svcCtx) {
+        gStorageEngineConcurrencyAdjustmentAlgorithm = "";
         // TODO SERVER-72616: Remove ifdefs once PriorityTicketHolder is available cross-platform.
 #ifdef __linux__
         if constexpr (std::is_same_v<PriorityTicketHolder, TicketHolderImpl>) {
diff --git a/src/mongo/db/storage/SConscript b/src/mongo/db/storage/SConscript
index 19547976e7a..b7258d7da1c 100644
--- a/src/mongo/db/storage/SConscript
+++ b/src/mongo/db/storage/SConscript
@@ -218,6 +218,7 @@ env.Library(
         '$BUILD_DIR/mongo/db/server_base',
         '$BUILD_DIR/mongo/db/service_context',
         '$BUILD_DIR/mongo/util/concurrency/ticketholder',
+        '$BUILD_DIR/mongo/util/processinfo',
         'storage_engine_feature_flags',
     ],
 )
diff --git a/src/mongo/db/storage/execution_control/throughput_probing.cpp b/src/mongo/db/storage/execution_control/throughput_probing.cpp
index 5087318776a..58040618713 100644
--- a/src/mongo/db/storage/execution_control/throughput_probing.cpp
+++ b/src/mongo/db/storage/execution_control/throughput_probing.cpp
@@ -30,6 +30,7 @@
 #include "mongo/db/storage/execution_control/throughput_probing.h"
 #include "mongo/db/storage/execution_control/throughput_probing_gen.h"
 #include "mongo/logv2/log.h"
+#include "mongo/util/processinfo.h"
 
 #define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kStorage
 
@@ -40,7 +41,14 @@ ThroughputProbing::ThroughputProbing(ServiceContext* svcCtx,
                                      TicketHolder* writeTicketHolder,
                                      Milliseconds interval)
     : TicketHolderMonitor(svcCtx, readTicketHolder, writeTicketHolder, interval),
-      _stableConcurrency(_readTicketHolder->outof()) {}
+      _stableConcurrency(throughput_probing::gInitialConcurrency
+                             ? throughput_probing::gInitialConcurrency
+                             : std::clamp(static_cast<int32_t>(ProcessInfo::getNumCores()),
+                                          kMinConcurrency,
+                                          kMaxConcurrency)) {
+    _readTicketHolder->resize(_stableConcurrency);
+    _writeTicketHolder->resize(_stableConcurrency);
+}
 
 void ThroughputProbing::appendStats(BSONObjBuilder& builder) const {
     _stats.serialize(builder);
diff --git a/src/mongo/db/storage/execution_control/throughput_probing.idl b/src/mongo/db/storage/execution_control/throughput_probing.idl
index 68a7ad559c5..f4418f6083e 100644
--- a/src/mongo/db/storage/execution_control/throughput_probing.idl
+++ b/src/mongo/db/storage/execution_control/throughput_probing.idl
@@ -38,3 +38,15 @@ server_parameters:
     validator:
       gte: 0.1
       lte: 0.5
+
+  throughputProbingInitialConcurrency:
+    description: >-
+      The initial number of concurrent read/write transactions for throughput probing. The default
+      value of 0 means to use the number of logical CPU cores.
+    set_at: startup
+    cpp_vartype: int32_t
+    cpp_varname: gInitialConcurrency
+    default: 0
+    validator:
+      gte: 5
+      lte: 128
diff --git a/src/mongo/db/storage/execution_control/throughput_probing_test.cpp b/src/mongo/db/storage/execution_control/throughput_probing_test.cpp
index 340cb616b5a..d2da4844ea9 100644
--- a/src/mongo/db/storage/execution_control/throughput_probing_test.cpp
+++ b/src/mongo/db/storage/execution_control/throughput_probing_test.cpp
@@ -28,6 +28,7 @@
  */
 
 #include "mongo/db/storage/execution_control/throughput_probing.h"
+#include "mongo/db/storage/execution_control/throughput_probing_gen.h"
 #include "mongo/unittest/unittest.h"
 
 namespace mongo::execution_control {
@@ -85,8 +86,10 @@ protected:
               svcCtx->setPeriodicRunner(std::move(runner));
               return runnerPtr;
           }()),
-          _readTicketHolder(size),
-          _writeTicketHolder(size) {}
+          _throughputProbing([&]() -> ThroughputProbing {
+              throughput_probing::gInitialConcurrency = size;
+              return {_svcCtx.get(), &_readTicketHolder, &_writeTicketHolder, Milliseconds{1}};
+          }()) {}
 
     void _run() {
         _runner->run(_client.get());
@@ -99,8 +102,7 @@ protected:
     MockTicketHolder _readTicketHolder;
     MockTicketHolder _writeTicketHolder;
 
-    ThroughputProbing _througputProbing{
-        _svcCtx.get(), &_readTicketHolder, &_writeTicketHolder, Milliseconds{1}};
+    ThroughputProbing _throughputProbing;
 };
 
 class ThroughputProbingMaxConcurrencyTest : public ThroughputProbingTest {