同时请求球衣休息服务

Question

I am developing a very simple REST web service with Eclipse, Tomcat7 and Jersey implementation, with a connection to MySQL. Looking to the jersey documentation i know that every request create a new object of the root resource class. But i dont know if every request is independet, for example if one request have to wait a long time, the server will accept more request normaly?

The problem is : I have 2 main classes, 1 class implements Jersey with annotations(Proxy.java), and other class that connects to a BD(Notificator.java), there is only one instance of this class (Singleton) in order to use only 1 Connection object. The classes who implements Jersey use this class. So, if one of the request is blocked , i dont know if the others will run because they are using the same (Notificator.java) instance.

The relation is N instances of(Proxy.java) uses the only one (Notificator.java) witch have one Connection to a MySQL.

Answer 1

Jersey is developed on top of servlets. There is a new thread for each of the incoming request. Your code is creating a bottleneck for all the threads as there is a contention for single available connection object. If you have multiple requests then only one request will be using that connection and others have to wait. If the wait is not too long then there is no problem. But if wait is more than the HTTP REQUEST TIMEOUT then your other requests may end up as TIMED OUT.

I understand that you may be having single connection bottleneck due to some business requriement/ complication. So in all such cases where we cannot process all the requests simulataneously and there can be variety of reasons for it, then we should create our web services as Asynchronous. Asynchronous web services work on the model of SUBMIT REQUEST-> REQUEST ACCEPTED(will be processed asynchronously) and JOB URL returned for polling-> CLIENT POLLS till the JOB IS NOT COMPLETED.

Hope it helps!

Answer 2

Try database connection pooling, more on this here:

http://en.wikipedia.org/wiki/Connection_pool

How to establish a connection pool in JDBC?