Http Connection Pooling in Camel

Question

I am using Camel as an Orchestration Engine.

clients sends HTTP request <-> CAMEL code <---- HTTP Req----- > external
server(s)

I am using HTTP4 Component (with default settings) for making HTTP Requests to external server. I have quite a few http backends.

Right now the way we are making http calls to our backend is as follow:-

// The producer is created during app initialisation. This is actually done
via blueprint.xml
ProducerTemplate producer = camelContext.createProducerTemplate();

// Whenever I need to make a http call I am executing the below code with
URL set as something like:- "http4://order-api:8099/orders/v1/ordersearch/"

Exchange exchange = producer.request(URL, new Processor() {
        @Override
        public void process(Exchange exchange) throws Exception {
        log.info("Executing the HTTP request : URL - " + URL + " Headers -
" + headers + " Body : " + body);
        exchange.getIn().setHeaders(headers);
        exchange.getIn().setBody(body);
        }
    });

The query I am having is:-

1. Does HTTP4 in the default setting camel uses some http connection pooling while making a call to the external servers?
2. If yes Is there a way I can configure the connection pooling from blueprint.xml?

I am using Camel 2.16.1 and the application is deployed in Karaf 3.0.5.

Answer 1

The http4 component use Apache HttpClient, which support pooling with the use of a HttpClientConnectionManager.

By default, camel uses a PoolingHttpClientConnectionManager which is configured with the properties connectionsPerRoute and maxTotalConnections.

If you want to have more control over this clientConnectionManager, you can provide your own implementation of org.apache.http.conn.HttpClientConnectionManager

See HttpClient connection manager