Best practices for High Availability (HA)

Avoid network latency between servers

IBM Traveler servers in an HA pool should all be located on the same network. IBM Traveler servers in an HA pool communicate server to server for both processing commands, as well as routing requests for load balancing. You should not disperse the IBM Traveler servers in the same HA pool across data centers.

If failover is configured for the database servers, the database servers should be located within the same network, preferably on the same switch. Transactional response time will be severely impacted if the commits to the secondary database server encounters slow network response time. This will affect the capacity of the overall HA pool.

In general, the IBM Traveler HA pool and the database servers should be co-located in the same data center.

Avoid single points of failure

Each component of IBM Traveler should be on its own server. For example, avoid hosting the mail servers and IBM Traveler on the same servers. This will reduce the impact of a server failure as well as improve performance.

Plan for failover

Size the servers in the HA pool such that there is spare capacity to handle failover. For example, assume a server capacity of 2000 devices and a total population of 4000 devices. A two server pool will not be adequate, as one server cannot handle 4000 devices in the event the other server is taken offline. Therefore, to adequately handle the device load in the event of one server going offline, three servers are required.