Normal operation (Main Server running / Standby Server standby)
The basic concept of the Main/Standby Solution is that the Standby Server takes the role of the running server in case the Main Server breaks down. In normal operation mode the Main Server is in “Running” state and manages a network of equipment. “Running” state signifies that all FOXMAN-UN base services and all FOXMAN-UN core services are running. In normal operation mode the Standby Server is in “Standby” state. “Standby” state signifies that all FOXMAN-UN base services are running but no FOXMAN-UN core services are running. Both Servers periodically do a backup of the following information:
• FOXMAN-UN Database,
• DIRAC database (if DIRAC server is installed),
• ALS Database (if ALS is installed).
The Standby Server is waiting to take over network management in case of a Main Server breakdown. Thereto it periodically polls the Main Server for new database backups and, if available, transfers them to itself. Immediately after the transfer has occurred the backups will be imported to the corresponding databases on the Standby Server. Server-specific information such as e.g. equipment agent IP addresses will be exchanged during import. Now the Standby Server is ready to take over network management in case of a Main Server breakdown.