Forums » Interstage BPM Server
Is "clustered server" the same as "high availability"?
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I have see that Interstage BPM server can be run as a cluster. That means that you have a bunch of servers all acting as one, right? Somewhere else I saw a mention of "High Availability". Is that the same thing. It seems like HA should be about a server always being available. Like reliability. Isn't a clustered server something else?Author: D. Opel Gaenger
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There is a lot of confusion around clustering, load balancing, and HA in general. People often mix the terms up.
To me, HA is about ensuring that the application/capability/functionality being provided is maintained (through hardware and software). It is not specific to, say, "machine A is always running", but rather that my business mission critical application is always available and functioning. How that functionality is provided is a black box for me... the key is that my functionality is always available - ie high availability.
Clustering is about setting up redundancy to facility HA. Clustering can be vertical (single machine) or horizontal (multiple machines). Smart software designed to support clustering can deliver a HA solution once configured in a cluster.
Load balancing is about routing traffic between different servers (machines usually) to ensure that the incoming workload can be shared without servers getting really slow. Slightly different concept to clustering, but similar in the sense that it is a technique for delivering HA.Author: Ivar Alexander
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