Full Active/Standby High Availability for YumaPro Servers
High availability is crucial for modern networks to meet their uptime goals. YumaPro SDK includes the YP-HA Protocol to provide High Availability (HA) for netconfd-pro servers.
Any number of servers are configured into an HA server pool. The servers start in dormant mode and then an external process, usually a High Availability Controller, commands one of the pool’s servers to become the active server and the remainder to become standby servers.
The active server behaves as a normal netconfd-pro server but in addition replicates any configuration edits it receives to each of the HA pool’s standby servers to keep them continually up to date. If a configuration edit involves loading YANG modules the active server commands the standbys to load the same YANG modules. As the YANG modules can be loaded and unloaded by the servers without having to restart this further improves system availability. Servers in standby mode just receive configuration edits and do not act on them.
If the active server is taken out of service for maintenance or fails for some reason the external process commands one of the HA pools standby servers to become active. It then replicates configuration changes to the remaining standby servers in the pool. It is also responsible for system notifications and retrieving state data.
For more details please see the netconfd-pro user manual, Section 2.13 High Availability.