CODEWITHSUNDEEP
javaout-of-memoryheap-memoryehcache
Nathan
Nathan

Reputation: 1661

EhCache PooledBasedBackEnd in heap-dump is way larger than maxBytesLocalHeap

I have an application using EhCache with the following configuration

ehcache.strategy=localTempSwap
ehcache.maxBytesLocalHeap=100M
ehcache.maxBytesLocalDisk=1G
ehcache.setEternal=false
ehcache.timeToLiveSeconds=7200
ehcache.timeToIdleSeconds=1800
ehcache.sizeOfPolicyConfiguration.maxDepth=1000000
disk.store.enabled=true
ehcache.cachemanager.disk.store.dir=/tmp/ehcache/

My Cache is created as follows...

            String maxBytesLocalHeap = configuration.getString("ehcache.maxBytesLocalHeap");
            String maxBytesLocalDisk = configuration.getString("ehcache.maxBytesLocalDisk");
            String strategy = configuration.getString("ehcache.strategy");
            boolean eternal = configuration.getBoolean("ehcache.setEternal");
            Long timeToLiveSeconds = configuration.getLong("ehcache.timeToLiveSeconds");
            Integer maxDepth = configuration.getInt("ehcache.sizeOfPolicyConfiguration.maxDepth");

            CacheConfiguration cacheConfiguration = new CacheConfiguration();
            cacheConfiguration.setName("be_ehcache");
            cacheConfiguration.setMaxBytesLocalHeap(maxBytesLocalHeap);
            cacheConfiguration.setMaxBytesLocalDisk(maxBytesLocalDisk);
            cacheConfiguration.setEternal(eternal);
            cacheConfiguration.setTimeToLiveSeconds(timeToLiveSeconds);
            cacheConfiguration.setMemoryStoreEvictionPolicyFromObject(MemoryStoreEvictionPolicy.LFU);

            PersistenceConfiguration persistenceConfiguration = new PersistenceConfiguration();
            persistenceConfiguration.strategy(strategy);
            persistenceConfiguration.synchronousWrites(eternal);
            cacheConfiguration.persistence(persistenceConfiguration);

            SizeOfPolicyConfiguration sizeOfPolicyConfiguration = new SizeOfPolicyConfiguration();
            sizeOfPolicyConfiguration.maxDepthExceededBehavior(MaxDepthExceededBehavior.ABORT);
            sizeOfPolicyConfiguration.setMaxDepth(maxDepth);
            cacheConfiguration.sizeOfPolicy(sizeOfPolicyConfiguration);

            Cache cache = new Cache(cacheConfiguration);

My application runs with 1GB of memory (-Xmx1024m). My application crashes daily with OutOfMemoryErrors. When I look at the heap dump, I see an object net.sf.ehcache.store.cachingtier.PooledBasedBackEnd when is generally 500MB in size (analyzed in VisualVM, calculating the Retained Size) and another object net.sf.ehcache.store.chm.SelectableConcurrentHashMap which is generally right around 100MB.

We are currently running using ehcache-2.9.0 (yes, I know it's an old version...)

Why doesn't my configuration of the maximum storage on the heap work? Or better, how can I effectively limit the amount the total heap-size that ehcache will use for my cached data?

Upvotes: 0

Views: 228

Answers (1)

Nathan
Nathan

Reputation: 1661

Found the root-cause. Another developer annotated the largest fields with @IgnoreSizeOf. This had the result that for all practical purposes, we ignore allow ehcache (with our data-constellation) to consume memory without limits.

Upvotes: 1

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