Wednesday, July 27, 2005

JCache and JBI: Caching in a SOA/ESB The JCache API rocks. Now if only the Expert Group would release a public draft of the RI I'd be very happy! :). Please guys - just ship an early access release or something real soon. Anyway... When working with SOA and ESBs caching often becomes important. If every time a service needs some data it always performs a remote request over HTTP/JMS on a back end system you often get large amounts of traffic and high latency and high loads on back end systems. Putting a cache in front of service requests can often save lots of traffic, increase throughput rate and take load of expensive back end systems. One of the downsides of Web Services in general (as opposed to REST) is they don't lend themselves very well to the web centric caching structures such as when using HTTP GET with the front end web cache. In ServiceMix we have a caching JBI component which works with any JCache provider. The nice thing about this is it works with any JCache provider (or even just a Map :) and can be used in any service pipeline or orchestration irrespective of the transport of the service (web service, HTTP REST, JMS, POJO) and caches at the service invocation level - usually in memory to avoid off-process caching overhead. The only tricky part is creating a key expression from the request; which typically a simple XPath expression will do the trick. BTW a tip to all those wishing to use JCache until the EG finally releases a public beta; just use a Map for your cache, use dependency injection and you'll be all set for JCache when its finally public :) 11:00:53 AM    comment []