How exactly would you define a session in this case? Also, isn't the point of the load balancer slightly lost? Instead of distributing the work according to the load on each server, it is now just mapping the work to the appropriate server. As it states in one of the bad implications of this approach, this could lead to limited load balance ability or none at all. There is a "workload balance" problem, where certain servers could have multiple requests and others could be idle, which counteracts the use of the load balancer.
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fangyihua
@mitraraman An example may be the namespace in a distributed file system. The load balance is not the entire picture. For example, AFS in a simple way partition users folders into different blocks, usr1,usr2...usr11,usr12...(not sure how many). Here, each of our andrew id is mapped to each of the different server, but the load balance may not be the same at all time or may not be able to adjust to the best server dynamically.
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kayvonf
@mitraman: Even if the load balancer has to direct requests associated with the same session to the same machine, it retains flexibility to make assignment decisions for new incoming sessions.
Also, on the next slide we discussed an alternative setup where the session was stored in a persistent store, like a database, resulting in the worker nodes being completely stateless.
How exactly would you define a session in this case? Also, isn't the point of the load balancer slightly lost? Instead of distributing the work according to the load on each server, it is now just mapping the work to the appropriate server. As it states in one of the bad implications of this approach, this could lead to limited load balance ability or none at all. There is a "workload balance" problem, where certain servers could have multiple requests and others could be idle, which counteracts the use of the load balancer.
This comment was marked helpful 0 times.
@mitraraman An example may be the namespace in a distributed file system. The load balance is not the entire picture. For example, AFS in a simple way partition users folders into different blocks, usr1,usr2...usr11,usr12...(not sure how many). Here, each of our andrew id is mapped to each of the different server, but the load balance may not be the same at all time or may not be able to adjust to the best server dynamically.
This comment was marked helpful 0 times.
@mitraman: Even if the load balancer has to direct requests associated with the same session to the same machine, it retains flexibility to make assignment decisions for new incoming sessions. Also, on the next slide we discussed an alternative setup where the session was stored in a persistent store, like a database, resulting in the worker nodes being completely stateless.
This comment was marked helpful 0 times.