> Node handles one request at a time. It isn't multithreaded. It will receive a request, process that request and return a response. If another request comes in at the same time another request is in process, it is queued until the currently processing request is finished.
I'm missing something here. Node does not multithread requests, but it surely can process many requests simultaneously if these requests are waiting for async operations: database, external APIs or other types of I/O usually. That's the very core idea of evented servers.
So, my model is that i.e. if a node process receives 100 requests over the period of 1 second, and each request takes 3 seconds to process but most of that time is spent waiting for async, then the 100 responses will be sent back essentially 3 seconds after they arrived, no queuing to speak of.
From your description, routers do not send multiple requests to the same dyno even if dynos could handle them, and only have a limited amount of dynos they talk to. So queuing is happening in the routers, while dynos idle away waiting for async.
This would be complementary to the problem described by Rapgenius, and mean that the Heroku architecture does not play well with any type of server, neither evented (Node, yours) nor sequential (Rails, as shown by Rapgenius) nor presumably multithreaded or multiprocess (which effectively behaves like evented to the outside world). A huge mess indeed!
I'm missing something here. Node does not multithread requests, but it surely can process many requests simultaneously if these requests are waiting for async operations: database, external APIs or other types of I/O usually. That's the very core idea of evented servers.
So, my model is that i.e. if a node process receives 100 requests over the period of 1 second, and each request takes 3 seconds to process but most of that time is spent waiting for async, then the 100 responses will be sent back essentially 3 seconds after they arrived, no queuing to speak of.
From your description, routers do not send multiple requests to the same dyno even if dynos could handle them, and only have a limited amount of dynos they talk to. So queuing is happening in the routers, while dynos idle away waiting for async.
This would be complementary to the problem described by Rapgenius, and mean that the Heroku architecture does not play well with any type of server, neither evented (Node, yours) nor sequential (Rails, as shown by Rapgenius) nor presumably multithreaded or multiprocess (which effectively behaves like evented to the outside world). A huge mess indeed!