... ensure that serversremain in service even when they are being upgraded depends on the type of server in use. There are two categories to consider: server clusters and single servers.The server clusterWhen ... Associates, Inc. All rights reserved.170|Chapter 5: Web Server Control, Monitoring, Upgrade, and Maintenanceproduction server, and the server has been restarted. Unfortunately, the service ... with -X, the control messages that the parent server normally writes to error_log (e.g., server started”, server stopped”, etc.) will not bewritten anywhere. httpd -X causes the server to handle...