play框架中的每个请求的线程

Question

I am a J2ee developer and i am new to play framework. I did a thorough research but not able to find any clear documentation on that.

The question is, how play handles a request. Will it creates a thread for every request just like J2ee containers?

If it is not Thread per request then what happens if we deploy the play application in Tomcat as war file.

Answer 1

Play 2.3.x uses Netty under the hood to handle HTTP request. You can learn more about Netty here You will also find informations on the Play documentation : https://www.playframework.com/documentation/2.3.x/ThreadPools

Answer 2

First, play2 framework does not support tomcat.

With play and netty, you don't assign one thread per request. By default you have one thread per core in Play but lets assume that you have only one thread for all requests;

In this architecture one thread is shared by all requests. So the thread handles the first request and when it's idle (it is idle when it calls to db or a url etc.) it begins to handle second request. So the thread does not have to return response for the first request to start the second one.

One might think that the system will get too slow with this architecture but it's not since the performance depends on cpu.