Ehcache 2.9.0中的ehcache死锁

Question

我们有使用ehcache 2.9.0的应用程序。最近，我们观察到与ehcache get/put操作相关的死锁，每周一次，一旦我们清除了缓存，这个问题就消失了。

我们在缓存get操作期间观察到RandomAccessFile上的锁定，在put操作期间观察到ReentrantReadWriteLock上的锁定。

询问ehcache专家对可能存在的问题的见解？

PFB线程转储中的线程

"HTTP938“#25950 java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync) prio=5 os_prio=0 tid=0x0000000002614000 nid=0x5a64 waiting on condition 0x00007fcd36965000 java.lang.Thread.State: WAITING ( parking ) at sun.misc.Unsafe.park(本地方法)-parking to wait <0x00000005cbbc6768> (在java.util.concurrent.locks.AbstractQueuedSynchronizer.的java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)等待守护进程)doAcquireShared(AbstractQueuedSynchronizer.java:967) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireShared(AbstractQueuedSynchronizer.java:1283) at java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock.lock(ReentrantReadWriteLock.java:727) at net.sf.ehcache.store.disk.Segment.flush(Segment.java:1010) at net.sf.ehcache.store.disk.DiskStore.flush(DiskStore.java:248) at net.sf.ehcache.store.CacheStore$1.evicted(CacheStore.java:99) atnet.sf.ehcache.store.CacheStore$1.evicted(CacheStore.java:96)在net.sf.ehcache.store.cachingtier.OnHeapCachingTier$1.evicted(OnHeapCachingTier.java:86)在net.sf.ehcache.store.cachingtier.CountBasedBackEnd$1.removed(CountBasedBackEnd.java:103)在net.sf.ehcache.util.concurrent.ConcurrentHashMap.internalReplace(ConcurrentHashMap.java:1346)在net.sf.ehcache.util.concurrent.ConcurrentHashMap.removeAndNotify(ConcurrentHashMap.java:2647)在net.sf.ehcache.store.cachingtier.CountBasedBackEnd.remove(CountBasedBackEnd.java:115)在net.sf.ehcache.store.cachingtier.OnHeapCachingTier.remove(OnHeapCachingTier.java:206)在net.sf.ehcache.store.CacheStore.put(CacheStore.java:134)在net.sf.ehcache.Cache.putInternal(Cache.java:1600)在net.sf.ehcache.Cache.put(Cache.java:1526)在net.sf.ehcache.Cache.put(Cache.java:1491)在org.springframework.cache.ehcache.EhCacheCache.put(EhCacheCache.java:82)在org.springframework.cache.interceptor.AbstractCacheInvoker.doPut(AbstractCacheInvoker.java:82)在org.springframework.cache.interceptor.CacheAspectSupport$CachePutRequest.apply(CacheAspectSupport.java:651)在org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:358)在org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:299)在org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61)在org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)的org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)

"HTTP927“#25855守护程序prio=5 os_prio=0 tid=0x00007fce685c9000 nid=0x4fb6正在等待监视器条目0x00007fcd359e8000 java.lang.Thread.State:在net.sf.ehcache.store.disk.DiskStorageFactory.read(DiskStorageFactory.java:362)被阻塞(在对象监视器上)-等待在net.sf.ehcache.store.disk.Segment.decode(Segment.java:171)在net.sf.ehcache.store.disk.DiskStorageFactory.retrieve(DiskStorageFactory.java:864)锁定<0x00000005cbdfb538> (a java.io.RandomAccessFile)at net.sf.ehcache.store.disk.Segment.remove(Segment.java:644) at net.sf.ehcache.store.disk.DiskStore.remove(DiskStore.java:625) at net.sf.ehcache.store.CacheStore.remove(CacheStore.java:236) at net.sf.ehcache.Cache.removeInternal(Cache.java:2401) at net.sf.ehcache.Cache.tryRemoveImmediately(Cache.java:2162) at net.sf.ehcache.Cache.get(Cache.java：1739年)在org.springframework.cache.ehcache.EhCacheCache.get(EhCacheCache.java:65) at org.springframework.cache.interceptor.AbstractCacheInvoker.doGet(AbstractCacheInvoker.java:68) at org.springframework.cache.interceptor.CacheAspectSupport.findInCaches(CacheAspectSupport.java:461) at org.springframework.cache.interceptor.CacheAspectSupport.findCachedItem(CacheAspectSupport.java:432) at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:333) at org.springframework.cache.interceptor.CacheAspectSupport.在org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)执行(CacheAspectSupport.java:299)

线程在java.io.RandomAccessFile.readFully(RandomAccessFile.java:416)上拥有监视器锁0x00000005cbdfb538 -在org.springframework.cache.ehcache.EhCacheCache.put(EhCacheCache.java:82)上锁定了HTTP762 0x00000005cbdfb538谢谢

Answer 1

我可能遗漏了一些东西，但我没有在您显示的线程转储中看到任何死锁。只有两个线程在等待不同的东西，而不是持有另一个线程。

第一次尝试必须逐出一个put上的值。

第二个线程注意到一个条目已过期，并将其从磁盘存储中删除。

您确定不是磁盘本身或缓存中的数据结构导致磁盘速度变慢？

我还建议迁移到2.10.4版本，这可能会使问题消失。