Application clustering definition
Application clustering is having several identical copies (called nodes) of software running on different servers or computers. Clustering makes the application more reliable, scalable, and always available. This, in turn, ensures uninterrupted service even if the hardware fails or the demand is very high. It's like having a team of workers handling tasks, and if one worker is unavailable, another steps in to ensure the work keeps going.
See also: database clustering
How does application clustering work?
Application clustering relies on load balancing and failover mechanisms. Here's how it works:
- When a request or task comes in, a load balancer decides which node should handle it based on server load, availability, or a predefined algorithm.
- If one node fails or encounters a problem, the load balancer quickly redirects requests to another healthy node. By doing so, the system ensures that the application remains available and users experience minimal downtime.
- Application clustering also helps distribute the workload evenly among nodes instead of piling it on a single node. This prevents any node from becoming overwhelmed, which would lead to slow performance or even crashes.
- You can add more nodes to the cluster as more users or requests come in. Instant scalability allows the application to handle increased traffic efficiently.
- In some cases, clustering involves synchronizing the data between the nodes so they all have the same information. This step is crucial for applications that rely on shared data, like databases.
