The InstrumentationProcessor is a delegate processor (aka interceptor) that allows you do do before and after processing. It is not really invoked twice (or I have to see a test case that does that, the unit tests in camel I am aware of don't). It is invoked once, takes a start timestamp, it delegates processing to the inner processor and then takes the time diff and records it.
Now with a DelegateProcessor all this call is synchronous. Being actually a DelegateAsyncProcessor, the call to the inner processor is done by the async engine (see AsyncProcessorHelper.process()) which calls asynchronously on the done() method. I assume this is what you see and interpret as a second call. This design is not wasting performance, quite to the contrary. It ensures a better use of resources and scales much better with higher message volume. I hope this helps, Hadrian On Dec 1, 2010, at 9:53 PM, ext2 wrote: > Hi: > Each camel processor will be wrapped with Instrument Interceptor > twice. So for each process , the Instrument interceptor will be executed > twice. > It seems no use but waste performance; > Why? Or a bug? > Thanks for any suggestion. > > >
