Less wrong

src/Interpreters/SystemLog.cpp

@@ -30,8 +30,7 @@ std::shared_ptr<TSystemLog> createSystemLog(
     const String & default_database_name,
     const String & default_table_name,
     const Poco::Util::AbstractConfiguration & config,
-    const String & config_prefix,
-    bool lazy_load)
+    const String & config_prefix)
 {
     if (!config.has(config_prefix))
         return {};
@@ -64,7 +63,7 @@ std::shared_ptr<TSystemLog> createSystemLog(
 
     size_t flush_interval_milliseconds = config.getUInt64(config_prefix + ".flush_interval_milliseconds", DEFAULT_SYSTEM_LOG_FLUSH_INTERVAL_MILLISECONDS);
 
-    return std::make_shared<TSystemLog>(context, database, table, engine, flush_interval_milliseconds, lazy_load);
+    return std::make_shared<TSystemLog>(context, database, table, engine, flush_interval_milliseconds);
 }
 
 }
@@ -72,14 +71,12 @@ std::shared_ptr<TSystemLog> createSystemLog(
 
 SystemLogs::SystemLogs(Context & global_context, const Poco::Util::AbstractConfiguration & config)
 {
-    bool lazy_load = config.getBool("system_tables_lazy_load", true);
-
-    query_log = createSystemLog<QueryLog>(global_context, "system", "query_log", config, "query_log", lazy_load);
-    query_thread_log = createSystemLog<QueryThreadLog>(global_context, "system", "query_thread_log", config, "query_thread_log", lazy_load);
-    part_log = createSystemLog<PartLog>(global_context, "system", "part_log", config, "part_log", lazy_load);
-    trace_log = createSystemLog<TraceLog>(global_context, "system", "trace_log", config, "trace_log", lazy_load);
-    text_log = createSystemLog<TextLog>(global_context, "system", "text_log", config, "text_log", lazy_load);
-    metric_log = createSystemLog<MetricLog>(global_context, "system", "metric_log", config, "metric_log", lazy_load);
+    query_log = createSystemLog<QueryLog>(global_context, "system", "query_log", config, "query_log");
+    query_thread_log = createSystemLog<QueryThreadLog>(global_context, "system", "query_thread_log", config, "query_thread_log");
+    part_log = createSystemLog<PartLog>(global_context, "system", "part_log", config, "part_log");
+    trace_log = createSystemLog<TraceLog>(global_context, "system", "trace_log", config, "trace_log");
+    text_log = createSystemLog<TextLog>(global_context, "system", "text_log", config, "text_log");
+    metric_log = createSystemLog<MetricLog>(global_context, "system", "metric_log", config, "metric_log");
 
     if (metric_log)
     {
@@ -99,6 +96,14 @@ SystemLogs::SystemLogs(Context & global_context, const Poco::Util::AbstractConfi
         logs.emplace_back(text_log.get());
     if (metric_log)
         logs.emplace_back(metric_log.get());
+
+    bool lazy_load = config.getBool("system_tables_lazy_load", true);
+    for (auto & log : logs)
+    {
+        if (!lazy_load)
+            log->prepareTable();
+        log->startup();
+    }
 }
 
 

src/Interpreters/SystemLog.h

@@ -73,6 +73,8 @@ public:
     virtual String getName() = 0;
     virtual ASTPtr getCreateTableQuery() = 0;
     virtual void flush() = 0;
+    virtual void prepareTable() = 0;
+    virtual void startup() = 0;
     virtual void shutdown() = 0;
     virtual ~ISystemLog() = default;
 };
@@ -117,8 +119,7 @@ public:
         const String & database_name_,
         const String & table_name_,
         const String & storage_def_,
-        size_t flush_interval_milliseconds_,
-        bool lazy_load);
+        size_t flush_interval_milliseconds_);
 
     /** Append a record into log.
       * Writing to table will be done asynchronously and in case of failure, record could be lost.
@@ -130,6 +131,9 @@ public:
     /// Flush data in the buffer to disk
     void flush() override;
 
+    /// Start the background thread.
+    void startup() override;
+
     /// Stop the background flush thread before destructor. No more data will be written.
     void shutdown() override
     {
@@ -178,7 +182,7 @@ private:
       * Renames old table if its structure is not suitable.
       * This cannot be done in constructor to avoid deadlock while renaming a table under locked Context when SystemLog object is created.
       */
-    void prepareTable();
+    void prepareTable() override;
 
     /// flushImpl can be executed only in saving_thread.
     void flushImpl(const std::vector<LogElement> & to_flush, uint64_t to_flush_end);
@@ -190,8 +194,7 @@ SystemLog<LogElement>::SystemLog(Context & context_,
     const String & database_name_,
     const String & table_name_,
     const String & storage_def_,
-    size_t flush_interval_milliseconds_,
-    bool lazy_load)
+    size_t flush_interval_milliseconds_)
     : context(context_)
     , table_id(database_name_, table_name_)
     , storage_def(storage_def_),
@@ -199,12 +202,12 @@ SystemLog<LogElement>::SystemLog(Context & context_,
 {
     assert(database_name_ == DatabaseCatalog::SYSTEM_DATABASE);
     log = &Logger::get("SystemLog (" + database_name_ + "." + table_name_ + ")");
+}
 
-    if (!lazy_load)
-    {
-        prepareTable();
-    }
 
+template <typename LogElement>
+void SystemLog<LogElement>::startup()
+{
     saving_thread = ThreadFromGlobalPool([this] { savingThreadFunction(); });
 }
 

src/Interpreters/TextLog.cpp

@@ -72,9 +72,9 @@ void TextLogElement::appendToBlock(Block & block) const
 
 TextLog::TextLog(Context & context_, const String & database_name_,
         const String & table_name_, const String & storage_def_,
-        size_t flush_interval_milliseconds_, bool lazy_load)
+        size_t flush_interval_milliseconds_)
   : SystemLog<TextLogElement>(context_, database_name_, table_name_,
-        storage_def_, flush_interval_milliseconds_, lazy_load)
+        storage_def_, flush_interval_milliseconds_)
 {
     // SystemLog methods may write text logs, so we disable logging for the text
     // log table to avoid recursion.

src/Interpreters/TextLog.h

@@ -36,8 +36,7 @@ public:
         const String & database_name_,
         const String & table_name_,
         const String & storage_def_,
-        size_t flush_interval_milliseconds_,
-        bool lazy_load);
+        size_t flush_interval_milliseconds_);
 };
 
 }