code: private int computeMemoryPercentUsed(Object cache) {
  		final int maxElementsInMemory = ((Ehcache) cache).getCacheConfiguration()
  				.getMaxElementsInMemory();
  		if (maxElementsInMemory == 0) {
  			// maxElementsInMemory peut être 0 (sans limite), cf issue 73
  			return -1;
  		}
  		return (int) (100 * inMemoryObjectCount / maxElementsInMemory);
  	}
docs: otherwise serialization would not work in the collector server or in jenkins scripts