Memory leak when using Eh107CacheManager.getCacheNames()

[whowrotethiscode]

Hello,

There seems to be a memory leak
when using Eh107CacheManager.getCacheNames()
in EhCache version 3.9.6:

<config
        xmlns='http://www.ehcache.org/v3'
        xmlns:jsr107='http://www.ehcache.org/v3/jsr107'>

    <service>
        <jsr107:defaults/>
    </service>

    <cache alias="cache-aaa">
        <heap>100000</heap>
    </cache>

    <cache alias="cache-bbb">
        <heap>999999</heap>
    </cache>

</config>

URL config = Test.class.getResource("/ehcache.xml");
CacheManager manager = Caching.getCachingProvider().getCacheManager(config.toURI(), null, null);

while (true) {
    manager.getCacheNames(); // This will eventually run out of memory
}

Each time Eh107CacheManager.getCacheNames() is invoked
the collections of "derivedStatistics" is increasing
which seems like a bug?

Please see the attached sample code which demonstrates this.

It looks like a possible solution to this problem
maybe to change "caches.putIfAbsent()" to "caches.computeIfAbsent()" in refreshAllCaches()
to avoid unnecessarily invoking wrapEhcacheCache().

Thanks.

ehcachetest.zip

[pbaddi]

Hi,

I am upgrading net.sf.ehcache ehcache from 2.10.6 to org.ehcache ehcache with 3.10.8 jakarta as classifier.
URL configUrl = getClass().getResource("/ehcache.xml");
CachingProvider cachingProvider = Caching.getCachingProvider("org.ehcache.jsr107.EhcacheCachingProvider");
javax.cache.CacheManager cacheManager = cachingProvider.getCacheManager(configUrl.toURI(), getClass().getClassLoader());
for (String cacheName : cacheManager.getCacheNames()) {
}
In many places , I am retrieveing cacheName with help of above code.

Is there any alternative get all the cache names if it creating memory leak issue?

In old code, we using below these attributes to display healthcheck of cache.
Map<String, Object> cacheMap = new TreeMap<String, Object>();
CacheConfiguration cacheConfig = cache.getCacheConfiguration();
CacheStatistics statistics = new CacheStatistics(cache);
cacheMap.put("DiskExpiryThreadIntervalSeconds", cacheConfig.getDiskExpiryThreadIntervalSeconds());
cacheMap.put("DiskPersistent", cacheConfig.isDiskPersistent());
cacheMap.put("Eternal", cacheConfig.isEternal());
cacheMap.put("MaxElementsInMemory", cacheConfig.getMaxElementsInMemory());
cacheMap.put("MaxElementsOnDisk", cacheConfig.getMaxElementsOnDisk());
cacheMap.put("MemoryStoreEvictionPolicy", cacheConfig.getMemoryStoreEvictionPolicy());
cacheMap.put("OverflowToDisk", cacheConfig.isOverflowToDisk());
cacheMap.put("TimeToIdleSeconds", cacheConfig.getTimeToIdleSeconds());
cacheMap.put("TimeToLiveSeconds", cacheConfig.getTimeToLiveSeconds());
cacheMap.put("CacheHits", statistics.getCacheHits());
cacheMap.put("CacheMisses", statistics.getCacheMisses());
cacheMap.put("InMemoryHits", statistics.getInMemoryHits());
cacheMap.put("ObjectCount", statistics.getMemoryStoreObjectCount());
cacheMap.put("OnDiskHits", statistics.getOnDiskHits());

What are alternative in 3.10.8. I could get few attributes but not all.

Is there any doc/example which can help me?

Any help on this appreciated.

Thanks,

[whowrotethiscode]

Hi @pbaddi,

Is there any alternative get all the cache names if it creating memory leak issue?

We are using the following code
to avoid the memory leak:

    public List<String> getCacheNames(javax.cache.CacheManager cacheManager) {
        return cacheManager
                .unwrap(org.ehcache.CacheManager.class)
                .getRuntimeConfiguration()
                .getCacheConfigurations()
                .keySet()
                .stream()
                .toList();
    }