Simply record the time from entering `main` to start listening sockets.
global_context->setDDLWorker(std::make_unique<DDLWorker>(pool_size, ddl_zookeeper_path, global_context, &config(),
                                                                     "distributed_ddl", "DDLWorker",
                                                                     &CurrentMetrics::MaxDDLEntryID, &CurrentMetrics::MaxPushedDDLEntryID));
        }
        {
            std::lock_guard lock(servers_lock);
            for (auto & server : servers)
            {
                server.start();
                LOG_INFO(log, "Listening for {}", server.getDescription());
            }
            global_context->setServerCompletelyStarted();
            LOG_INFO(log, "Ready for connections.");
        }
        try
        {
            global_context->startClusterDiscovery();
        }
        catch (...)
        {
            tryLogCurrentException(log, "Caught exception while starting cluster discovery");
        }
#if defined(OS_LINUX)
        
        
        
        systemdNotify("READY=1\n");
#endif
        SCOPE_EXIT_SAFE({
            LOG_DEBUG(log, "Received termination signal.");