|
|
|
|
|
|
by NathanKP
2904 days ago
|
|
|
It's not quite that straightforward. Lambda is more expensive per cycle if you are capable of keeping an instance fully utilized and getting every cycle out of that machine. After all if your Node.js or Go code takes say 20ms per request and can handle many concurrent requests you can squeeze a LOT of requests per second from a single instance. But many workloads don't have that high of a request volume and can't actually make full use of an instance. If you have a small API or service that gets one or two requests every few seconds then paying for a 100ms chunk of Lambda execution time every couple seconds is going to be much cheaper than reserving an entire instance and then not being able to get good utilization out of it. The tipping point is whether or not you have enough workload volume to keep an instance busy at all times. So for example password hashing in the article above. Because password hashing is deliberately CPU intensive it is very easy to keep an EC2 instance busy with even a low request volume. For a good hashing algorithm with lots of rounds its not uncommon to only get 10 authentications per second per core, because the algorithm is deliberately designed to be CPU heavy. So if you process more than 10 auths/sec then its probably cheaper to put the workload in a container that runs on an instance because you can keep that instance busy. But if the same service is only handling one or two password hashes every minute, then you can save money by only paying for 100ms increments when an auth request arrives, and stop paying when there is nothing to do. |
|
|