Stacking node balancers with session stickiness
https://www.linode.com/community/questions/23123/stacking-node-balancers-with-session-stickiness#Hello, I have read this one https://www.linode.com/community/questions/20944/multiple-nodebalancers
And I am confused with this line
"also need to consider whether your setup requires session stickiness, as this could have an impact on how the multiple NodeBalancers handle incoming requests and/or could result in one of the NodeBalancers exceeding the 10,000 concurrent connections limit despite having multiple NodeBalancers set up."
Does this mean, with session stickiness, I am still bound to the 10k concurrent connections limit?
I was planning to structure my node balancers likes this:
Parent node balancer -> Child nodebalancers (That could be horizontally scale)-> Linodes
Would love to test the setup, but would like to hear some comments before proceeding. Any inputs are appreciated.
1 Reply
CassandraD
Linode Staff
I believe the note you shared is saying that each NodeBalancer is subject to the 10k concurrent connection limit. Since Session Stickiness will cause a NodeBalancer to route subsequent requests from the same client to the same backend, I think the idea here is that Sticky Sessions might end up routing too much traffic to one backend node through the same NodeBalancer, which could cause that NodeBalancer to hit the connection limit sooner than necessary.
I also wanted to add that I don't believe the configuration you suggested would work:
Parent node balancer -> Child nodebalancers (That could be horizontally scale)-> Linodes
When you choose the backend nodes for the parent NodeBalancer, you wouldn't be able to choose the other NodeBalancer IPs since only Linodes are supported. To achieve that you'd might want to look into using HAProxy for a custom load balancing solution. I cannot say that would work either, but you can likely find more information about that on HAProxy's discussion site.