The availability of this layer within the IT environment is critical for real-time access to applications and databases. A network can be made up of multiple vendors hardware and software products, all providing a critical element in the network equation. In developing true high availability solutions, this layer will be challenging for most vendors. IBM has the unique skills and solutions to meet this challenge. High availability with system clustering Both planned and unplanned hardware and software failures can be reduced or eliminated through clustering.
Clusters are essentially multiple servers that are used as a single unified resource.
By inter-connecting multiple servers many times with access to shared resources, the resulting cluster is able to deliver greater availability. This increase in availability is due to the ability of the other systems in a cluster to assume the workload of a failing system resource. Likewise, maintaining access to data is a key element for high availability. If your server is running but it can't reach critical data, your business may cease to function. Properly designed cluster solutions can also reduce or eliminate planned outages due to hardware or software upgrades by allowing selected systems to be taken off-line for nondisruptive upgrades.