Refactor initialize of background pool (#5190)

close #5189

dbms/src/Interpreters/Context.cpp

@@ -68,18 +68,16 @@
 #include <fmt/core.h>
 
 #include <boost/functional/hash/hash.hpp>
-#include <map>
 #include <pcg_random.hpp>
 #include <set>
+#include <unordered_map>
 
 
 namespace ProfileEvents
 {
 extern const Event ContextLock;
 }
 
-#include <set>
-
 namespace CurrentMetrics
 {
 extern const Metric GlobalStorageRunMode;
@@ -1440,20 +1438,32 @@ void Context::dropCaches() const
         shared->mark_cache->reset();
 }
 
-BackgroundProcessingPool & Context::getBackgroundPool()
+BackgroundProcessingPool & Context::initializeBackgroundPool(UInt16 pool_size)
 {
     auto lock = getLock();
     if (!shared->background_pool)
-        shared->background_pool = std::make_shared<BackgroundProcessingPool>(settings.background_pool_size);
+        shared->background_pool = std::make_shared<BackgroundProcessingPool>(pool_size);
     return *shared->background_pool;
 }
 
-BackgroundProcessingPool & Context::getBlockableBackgroundPool()
+BackgroundProcessingPool & Context::getBackgroundPool()
+{
+    auto lock = getLock();
+    return *shared->background_pool;
+}
+
+BackgroundProcessingPool & Context::initializeBlockableBackgroundPool(UInt16 pool_size)
 {
-    // TODO: choose a better thread pool size and maybe a better name for the pool
     auto lock = getLock();
     if (!shared->blockable_background_pool)
-        shared->blockable_background_pool = std::make_shared<BackgroundProcessingPool>(settings.background_pool_size);
+        shared->blockable_background_pool = std::make_shared<BackgroundProcessingPool>(pool_size);
+    return *shared->blockable_background_pool;
+}
+
+BackgroundProcessingPool & Context::getBlockableBackgroundPool()
+{
+    // TODO: maybe a better name for the pool
+    auto lock = getLock();
     return *shared->blockable_background_pool;
 }
 

dbms/src/Interpreters/Context.h

@@ -379,7 +379,9 @@ class Context
     void setUseL0Opt(bool use_l0_opt);
     bool useL0Opt() const;
 
+    BackgroundProcessingPool & initializeBackgroundPool(UInt16 pool_size);
     BackgroundProcessingPool & getBackgroundPool();
+    BackgroundProcessingPool & initializeBlockableBackgroundPool(UInt16 pool_size);
     BackgroundProcessingPool & getBlockableBackgroundPool();
 
     void createTMTContext(const TiFlashRaftConfig & raft_config, pingcap::ClusterConfig && cluster_config);
@@ -505,7 +507,7 @@ class DDLGuard
 class SessionCleaner
 {
 public:
-    SessionCleaner(Context & context_)
+    explicit SessionCleaner(Context & context_)
         : context{context_}
     {}
     ~SessionCleaner();

dbms/src/Server/Server.cpp

@@ -54,10 +54,15 @@
 #include <Poco/Net/NetException.h>
 #include <Poco/StringTokenizer.h>
 #include <Poco/Timestamp.h>
+#include <Server/HTTPHandlerFactory.h>
+#include <Server/MetricsPrometheus.h>
+#include <Server/MetricsTransmitter.h>
 #include <Server/RaftConfigParser.h>
 #include <Server/Server.h>
 #include <Server/ServerInfo.h>
+#include <Server/StatusFile.h>
 #include <Server/StorageConfigParser.h>
+#include <Server/TCPHandlerFactory.h>
 #include <Server/UserConfigParser.h>
 #include <Storages/FormatVersion.h>
 #include <Storages/IManageableStorage.h>
@@ -82,12 +87,6 @@
 #include <limits>
 #include <memory>
 
-#include "HTTPHandlerFactory.h"
-#include "MetricsPrometheus.h"
-#include "MetricsTransmitter.h"
-#include "StatusFile.h"
-#include "TCPHandlerFactory.h"
-
 #if Poco_NetSSL_FOUND
 #include <Poco/Net/Context.h>
 #include <Poco/Net/SecureServerSocket.h>
@@ -1144,6 +1143,12 @@ int Server::main(const std::vector<std::string> & /*args*/)
         global_context->getPathCapacity(),
         global_context->getFileProvider());
 
+    /// Initialize the background & blockable background thread pool.
+    Settings & settings = global_context->getSettingsRef();
+    LOG_FMT_INFO(log, "Background & Blockable Background pool size: {}", settings.background_pool_size);
+    auto & bg_pool = global_context->initializeBackgroundPool(settings.background_pool_size);
+    auto & blockable_bg_pool = global_context->initializeBlockableBackgroundPool(settings.background_pool_size);
+
     global_context->initializePageStorageMode(global_context->getPathPool(), STORAGE_FORMAT_CURRENT.page);
     global_context->initializeGlobalStoragePoolIfNeed(global_context->getPathPool());
     LOG_FMT_INFO(log, "Global PageStorage run mode is {}", static_cast<UInt8>(global_context->getPageStorageRunMode()));
@@ -1260,13 +1265,6 @@ int Server::main(const std::vector<std::string> & /*args*/)
     /// Load global settings from default_profile and system_profile.
     /// It internally depends on UserConfig::parseSettings.
     global_context->setDefaultProfiles(config());
-    Settings & settings = global_context->getSettingsRef();
-
-    /// Initialize the background thread pool.
-    /// It internally depends on settings.background_pool_size,
-    /// so must be called after settings has been load.
-    auto & bg_pool = global_context->getBackgroundPool();
-    auto & blockable_bg_pool = global_context->getBlockableBackgroundPool();
 
     /// Initialize RateLimiter.
     global_context->initializeRateLimiter(config(), bg_pool, blockable_bg_pool);

dbms/src/Storages/BackgroundProcessingPool.h

@@ -81,7 +81,7 @@ class BackgroundProcessingPool
     using TaskHandle = std::shared_ptr<TaskInfo>;
 
 
-    BackgroundProcessingPool(int size_);
+    explicit BackgroundProcessingPool(int size_);
 
     size_t getNumberOfThreads() const { return size; }
 
@@ -96,7 +96,7 @@ class BackgroundProcessingPool
     /// 2. thread B also get the same task
     /// 3. thread A finish the execution of the task quickly, release the task and try to update the next schedule time of the task
     /// 4. thread B find the task is not occupied and execute the task again almost immediately
-    TaskHandle addTask(const Task & task, const bool multi = true, const size_t interval_ms = 0);
+    TaskHandle addTask(const Task & task, bool multi = true, size_t interval_ms = 0);
     void removeTask(const TaskHandle & task);
 
     ~BackgroundProcessingPool();

dbms/src/TestUtils/TiFlashTestEnv.cpp

@@ -39,6 +39,11 @@ void TiFlashTestEnv::initializeGlobalContext(Strings testdata_path, PageStorageR
     KeyManagerPtr key_manager = std::make_shared<MockKeyManager>(false);
     global_context->initializeFileProvider(key_manager, false);
 
+    // initialize background & blockable background thread pool
+    Settings & settings = global_context->getSettingsRef();
+    global_context->initializeBackgroundPool(settings.background_pool_size);
+    global_context->initializeBlockableBackgroundPool(settings.background_pool_size);
+
     // Theses global variables should be initialized by the following order
     // 1. capacity
     // 2. path pool