[WSO2 ESB] Improve Callout Mediator Performance

Callout mediator internally uses the axis2 CommonsHTTPTransportSender to invoke services.

According to [1] MultiThreadedHttpConnectionManager which manages the connections, only allow two simultaneous connections at a time per a host. So with slow back-end services we will experience a significant degrade in the performance.

To overcome this issue we can alter the default configuration and increase the number of simultaneous connections.

We can set the CommonsHTTPTransportSender parameters as follows at

<ESB_HOME>/samples/axis2Client/client_repo/conf/axis2.xml

        HTTP/1.1
        chunked
        true
        100

In the above configuration, defaultMaxConnectionsPerHost parameter has increased to 100.

For more information about improving axis2 http transport client, refer to the resource available at [1].

[1] http://amilachinthaka.blogspot.com/2010/01/improving-axis2-http-transport-client.html