All right, load Balancers.
Load Balancers' whole purpose is to distribute the load of a single system
across multiple systems, controlling the number of requests to protect against rate
based attacks like denial service or distributed denial service attacks.
So you're distributing it across multiple servers, a distributed system.
Couple of different flavors.
You've got session affinity.
When an algorithm tracks the session cookie, forwards all the client's requests
in that session to the same application server.
Round robin actually distributes incoming
request sequ according to the weights assigned to the servers.
Least connections allocates new
connections to the server that's doing the least at that point.
And then random connections, the load Balancer selects two servers randomly
sends request to the one chosen by applying the Least Connections algorithm.
All right, so round robin, that goes way
back to DNS round robinning where you had multiple records for the same resource.
So any situation where you're dividing the
workload across multiple hosts, you've got some concerns.
Session affinity, what happens if my
connection is being sent to another server?
I've established connection with it.
Clustering and load balancing are also similar discussions.