What is the best way for pooling httpclient?

Question

My main goal is for pooling a httpclient in silent or somehow, and i'd like to call a method to give me a httpclient...because i think its too resource usage for every rest call add a new httpclient instance and set the things and so on...is there best practice for it?

Answer 1

If you refer to Apache HTTP client then you may follow the steps below:

1. Initiate Apache HTTP client only once, since it is thread safe you can safely reuse it. If you use Spring then it should be safe to store it in the Spring Context as a Bean. See following link for the thread-safety.

2. Despite the fact that HTTP client instance itself is not pooled (since you gonna use single instance of it) what you can do to increase the performance is configuring pooled connection manager on the HTTP client. See following link for the details. (search for the 'Pooling connection manager' on that page) . The actual code should be something similar to the snippet bellow :

PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
// Increase max total connection to 200
cm.setMaxTotal(200);
// Increase default max connection per route to 20
cm.setDefaultMaxPerRoute(20);
// Increase max connections for localhost:80 to 50
HttpHost localhost = new HttpHost("localhost", 80);
cm.setMaxPerRoute(new HttpRoute(localhost), 50);

CloseableHttpClient httpClient = HttpClients.custom()
        .setConnectionManager(cm)
        .build();

Hope this helps .