Simply record the time from entering `main` to start listening sockets.
attachInformationSchema(global_context, *database_catalog.getDatabase(DatabaseCatalog::INFORMATION_SCHEMA));
        attachInformationSchema(global_context, *database_catalog.getDatabase(DatabaseCatalog::INFORMATION_SCHEMA_UPPERCASE));
        
        
        
        database_catalog.loadMarkedAsDroppedTables();
        
        loadMetadata(global_context, default_database);
        convertDatabasesEnginesIfNeed(global_context);
        startupSystemTables();
        database_catalog.loadDatabases();
        
        database_catalog.assertDatabaseExists(default_database);
        
        global_context->getUserDefinedSQLObjectsLoader().loadObjects();
    }
    catch (...)
    {
        tryLogCurrentException(log, "Caught exception while loading metadata");
        throw;
    }
    LOG_DEBUG(log, "Loaded metadata.");
    
    
#if USE_UNWIND && !WITH_COVERAGE
    
    if (hasPHDRCache())
    {
        global_context->initializeTraceCollector();