"Mule 3.1 performance is in average 10% better than its predecessor version 2.2.7, performing better when the number of concurrent consumers gets bigger and much better when dealing with XSLT transformations (around 15% better)."A clear difference from the previous results from Mulesoft is that they are only testing concurrency levels of 20,40,80 & 160 this time, while dropping the 320, 640, 1280 and 2560 concurrent user test scenarios from this round! They have not published results against the 100K message sizes either - or for the WS-Security test case introduced by AdroitLogic last February [See http://esbperformance.org].
Its interesting to note both Mule and WSO2 now follows a pattern of performance testing only against previous versions of their own ESBs - when previously both published performance figures over each other; other open source ESBs and even commercial equivalents.
AdroitLogic first published the figures for its UltraESB in February 2010, and took a decision to compare its performance against competition - but not to release the names of the other products tested. Instead, it ships the complete ESB Performance Test Framework including scripts to run and convert results into CSVs, so that an end user can easily compare its performance against virtually any other comparative ESB (even commercial alternatives) on an exact same hardware and software configuration for a true apples-to-apples comparison.