Hi Just a heads up on https://issues.apache.org/jira/browse/CAMEL-3922 I have committed that to trunk in SVN rev: 1098574.
The change will use a SoftReference cache for the following internal caches in camel-core - endpoint cache - producer cache - consumer cache - bean info cache - property editor type converter (miss cache) So what we will have in org.apache.camel.util is 2 kind of LRU caches - LRUCache = uses strong reference cache and ensure data in cache is kept until explicit removed - LRUSoftCache = uses soft reference cache, will allows JVM to GC values from the cache, in case it runs low on memory There is an LRUSoftCacheTest unit test which demonstrates the situation with the JVM running out of memory. If you change the test to use the LRUCache then you will quickly run out of memory. So what the LRUSoftCache offers over the LRUCache is that in case the JVM is running low on memory, it allows the JVM to claim the memory for the values in the cache. Its kinda like auto-shrink if we run low on memory. Since its a cache, then we will just re-create the value in case there was a cache miss. Also the max cache size is of course still in-play. So if the cache has a limit of 1000, then only at most 1000 values is stored in the cache. And its LRU based, so we prefer to keep the most used. I gave the full project a test and didn't encounter any issues due this change. But in case you discover some odd behavior after this change, then let us know. Also if you are keen on cache code, then take a look and review the LRUSoftCache source code. I will add some JMX stats for the cache, so we at runtime can see some stats such as cache hit/miss etc. You can read about soft references here (notice it indicate its for memory sensitive caches) http://download.oracle.com/javase/6/docs/api/java/lang/ref/package-summary.html If you wonder why we are not using weak references instead, then that's actually a poor choice for caches. See for example what Google say: http://guava-libraries.googlecode.com/svn/tags/release09/javadoc/com/google/common/collect/MapMaker.html#weakValues() -- Claus Ibsen ----------------- FuseSource Email: cib...@fusesource.com Web: http://fusesource.com CamelOne 2011: http://fusesource.com/camelone2011/ Twitter: davsclaus Blog: http://davsclaus.blogspot.com/ Author of Camel in Action: http://www.manning.com/ibsen/
