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Thank you for the answer! It's currently operating at 5 Gbps, but it is expected to scale significantly based on traffic trends. It appears to be more cost-eff

Thank you for the answer! It's currently operating at 5 Gbps, but it is expected to scale significantly based on traffic trends. It appears to be more cost-effective to rent multiple 5 Gbps boxes rather than a single 20 Gbps box. The protocol used is protobuf over HTTPS (not gRPC) without channels, and it is stateless. The application proxies requests to underlying services, and is capable of handling 10 Gbps of requests on 8 cores. While the likelihood of a DDoS attack seems low, it is not entirely immune. Though there is no strict SLA, the service aims for availability 99.5% of the time

toast0 3y ago
Your 99.5% target simplifies failover. As long as you don't do it very often, you can just drop sessions; it's not ideal, but it's within your target and just carefully schedule the maitenance (and take the failures when they happen). If you can, the least equipment option would be to run ECMP from your application servers; no need for a load balancer at all. If you can run 10Gbps on 8 cores, a 16-core server (which is a small server) might do all you need; if so, you could do CARP/VVRP/IP takeover and have everything run through one box at a time. Or, HAProxy will work fine in front. If you want to make it easier for HAProxy, don't terminate TLS on those, run in tcp mode and let the application server do TLS; but then you can't let HAProxy split requests. If that works for you, you could do better with something that can do Direct Server Return so your load balancer doesn't need to process outbound traffic, but I don't have experience running that kind of load balancer (only being behind one), so no software recommendations. For HAProxy, especially tcp mode HAProxy, you want a power of two CPU cores that's no more than the number of NIC queues, hyper threads disabled. If you do it right, all the traffic stays on the same CPU, although it's tricky to align the backend connections.

toast0 3y ago

Your 99.5% target simplifies failover. As long as you don't do it very often, you can just drop sessions; it's not ideal, but it's within your target and just carefully schedule the maitenance (and take the failures when they happen). If you can, the least equipment option would be to run ECMP from your application servers; no need for a load balancer at all. If you can run 10Gbps on 8 cores, a 16-core server (which is a small server) might do all you need; if so, you could do CARP/VVRP/IP takeover and have everything run through one box at a time. Or, HAProxy will work fine in front. If you want to make it easier for HAProxy, don't terminate TLS on those, run in tcp mode and let the application server do TLS; but then you can't let HAProxy split requests. If that works for you, you could do better with something that can do Direct Server Return so your load balancer doesn't need to process outbound traffic, but I don't have experience running that kind of load balancer (only being behind one), so no software recommendations. For HAProxy, especially tcp mode HAProxy, you want a power of two CPU cores that's no more than the number of NIC queues, hyper threads disabled. If you do it right, all the traffic stays on the same CPU, although it's tricky to align the backend connections.