[jbosscache-issues] [JBoss JIRA] Resolved: (JBCACHE-1512) extremely high memory usage problem

extremely high memory usage problem ----------------------------------- Key: JBCACHE-1512 URL: https://jira.jboss.org/jira/browse/JBCACHE-1512 Project: JBoss Cache Issue Type: Bug Security Level: Public(Everyone can see) Components: Cache loaders Affects Versions: 3.1.0.GA Environment: windows XP, windows enterprise 2003 R2, Ubuntu 8.1, Redhat 5.3 Reporter: sridhar reddy Assignee: Manik Surtani Priority: Blocker Attachments: Matcher.zip My requirement is to associate a set of key value pairs together. all these kind of key value pairs are grouped together. So i am populating all the set of value pairs in hashmap. Group of such set of maps in a node . When i populate the entire HashMap t oncewith 1000 object and persisted in cache, the data file size is around 100K. and its perfect. But when i repeated the population of cache in iteratively i mean gradually, with the same 1000 objects, the data file is grown to 30MB. how bad. When i replaced the hashmap with the set, the data size remains same in both the ways. but for me the i need hashmap. one step population code is Code: public class TestCache { private Cache<Long, Object> cache = null; public TestCache(){ try { CacheFactory<Long, Object> factory = new DefaultCacheFactory<Long, Object>(); String cacheConfigFile = "cacheloader.xml"; cache = factory.createCache(cacheConfigFile); cache.create(); cache.start(); } catch (ConfigurationException e) { } catch (CacheException e) { } } public void populateCache(){ Map<Long, Object> empMap= new HashMap<Long, Object>(); for(long i=1; i <= 1000; i++){ Employee emp = new Employee(i,"Test name "+i,"test region "+i); empMap.put(i, emp); } Node<Long, Object> collNode = cache.getRoot().addChild(Fqn.fromElements("test","emp","cache")); collNode.put(0L, empMap); cache.stop(); } public static void main(String[] args) { TestCache tc= new TestCache(); tc.populateCache(); } } the second program which kept iteratively is Code: public class TestCache { private Cache<Long, Object> cache = null; public TestCache(){ try { CacheFactory<Long, Object> factory = new DefaultCacheFactory<Long, Object>(); String cacheConfigFile = "cacheloader.xml"; cache = factory.createCache(cacheConfigFile); cache.create(); cache.start(); } catch (ConfigurationException e) { } catch (CacheException e) { } } public void populateCache(){ Map<Long, Object> empMap= null; for(long i=1; i <= 1000; i++){ Employee emp = new Employee(i,"Test name "+i,"test region "+i); Node<Long, Object> collNode = cache.getRoot().getChild(Fqn.fromElements("test","emp","cache")); if(collNode == null){ collNode = cache.getRoot().addChild(Fqn.fromElements("test","emp","cache")); } empMap = (Map<Long, Object>)collNode.get(0L); if(empMap == null) empMap= new HashMap<Long, Object>(); empMap.put(i, emp); collNode.clearData(); collNode.remove(0L); collNode.put(0L, empMap); } cache.stop(); } public static void main(String[] args) { TestCache tc= new TestCache(); tc.populateCache(); } } configuration file is Code: <?xml version="1.0" encoding="UTF-8"?> <jbosscache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:jboss:jbosscache-core:config:3.0"> <transaction transactionManagerLookupClass="org.jboss.cache.transaction.GenericTransactionManagerLookup" /> <locking isolationLevel="REPEATABLE_READ" lockParentForChildInsertRemove="false" lockAcquisitionTimeout="20000" nodeLockingScheme="mvcc" writeSkewCheck="false" concurrencyLevel="500"/> <invocationBatching enabled="true"/> <jmxStatistics enabled="true"/> <loaders passivation="false" shared="false"> <preload> <node fqn="/" /> </preload> <loader class ="org.jboss.cache.loader.jdbm.JdbmCacheLoader" async="false" fetchPersistentState="true" ignoreModifications="false" > <properties> location=/home/sridhar/cache cache.jdbc.connection.factory=org.jboss.cache.loader.C3p0ConnectionFactory c3p0.maxPoolSize=10 c3p0.checkoutTimeout=5000 </properties> </loader> </loaders> </jbosscache> in the second program when i replaced the HashMap with Set, there is no difference in the size of data files created. Why such strange behaviour. what will be the solution to this?