There are several ways to tune performance in Mule. I’ve just finished a page on performance tuning in the Mule 2.x User Guide that walks through the available performance tuning options and provides formulas for calculating threads. Following is an excerpt of the high-level information from that page.
On November 18, 2008 at 9:00 AM PST (15:00 GMT) Wey Cheng and I will be presenting a webinar on Using MuleHQ to Manage Performance. You can register for the webinar here. Wey and I have been preparing an example to demonstrate typical read-world application performance issues and how to use MuleHQ to troubleshoot and resolve them. The webinar will focus on a live demo running a Mule application under load, observing some performance degradation,
MuleSoft provides the most widely used integration platform for connecting any application, data source or API, whether in the cloud or on-premises. With Anypoint Platform®, MuleSoft delivers a complete integration experience built on proven open source technology, eliminating the pain and cost of point-to-point integration. Anypoint Platform includes CloudHub™ iPaaS, Mule ESB™, and a unified solution for API management™, design and publishing.