On Fri, 20 Dec 2013, George Kadianakis wrote:
For this reason we started wondering whether DNS-round-robin-like scalability is actually worth such trouble. AFAIK most big websites use DNS round-robin, but is it necessary? What about application-layer solutions like HAProxy? Do application-layer load balancing solutions exist for other (stateful) protocols (IRC, XMPP, etc.)?
I think HAProxy and DNS round-robin solve different kinds of scalability issues:
- the application running behind the hidden service is taking too much ressources for a single node. Something like HAProxy can help split the application on multiple nodes, but all traffic still go through a single node.
- the network bandwidth that a single node can have or the number of connections it can handle is not enough. A solution like HAProxy doesn't help, because everything still has to go through a single node. I think the DNS round-robin is used to solve this kind of problem.