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

[sridhar reddy (JIRA)]

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



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?

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