Merge branch 'master' into cleanup

Author: pmenon

src/common/init.cpp

@@ -31,13 +31,14 @@ namespace peloton {
 ThreadPool thread_pool;
 
 void PelotonInit::Initialize() {
-  CONNECTION_THREAD_COUNT = std::thread::hardware_concurrency();
+  CONNECTION_THREAD_COUNT = settings::SettingsManager::GetInt(
+          settings::SettingId::connection_thread_count);
   LOGGING_THREAD_COUNT = 1;
   GC_THREAD_COUNT = 1;
   EPOCH_THREAD_COUNT = 1;
 
   // set max thread number.
-  thread_pool.Initialize(0, std::thread::hardware_concurrency() + 3);
+  thread_pool.Initialize(0, CONNECTION_THREAD_COUNT + 3);
 
   // start worker pool
   threadpool::MonoQueuePool::GetInstance().Startup();
@@ -47,7 +48,7 @@ void PelotonInit::Initialize() {
     threadpool::MonoQueuePool::GetBrainInstance().Startup();
   }
 
-  int parallelism = (std::thread::hardware_concurrency() + 3) / 4;
+  int parallelism = (CONNECTION_THREAD_COUNT + 3) / 4;
   storage::DataTable::SetActiveTileGroupCount(parallelism);
   storage::DataTable::SetActiveIndirectionArrayCount(parallelism);
 

src/include/settings/settings.h

@@ -97,6 +97,11 @@ SETTING_int(monoqueue_worker_pool_size,
             4,
             false, false)
 
+// Number of connection threads used by peloton
+SETTING_int(connection_thread_count,
+            "Number of connection threads (default: std::hardware_concurrency())",
+            std::thread::hardware_concurrency(), false, false)
+
 //===----------------------------------------------------------------------===//
 // WRITE AHEAD LOG
 //===----------------------------------------------------------------------===//