Clustering Vs Load balancing.
Both sound like a same this, and they are at the point of use. But what is the difference between clustering and load balancing.
Clustering is a group of resources working as a single unit. Each member of a cluster, exchange information with their clustered nodes or can say with members. Each node continuously replicate information with other nodes and check their stats on a particular channel. Each nodes always have the updated information and they continuously check their stats, so if one node is busy, other node will be serve the query. that’s mean they also can do the load balancing.
Load balancing : Two identical machines a load balancer device. Device route the request to one of them basis on load mechanism either it can be request per second or the size of request. Load balancer check the stats of machines before routing and request so if one machine is down, then all request will be send to available machine. Load balancer also check the stats of request, if user already have a session then it will be routed to same machine.
Their are plenty of other ways available for sharing the sessions like Memcached.