我正在嵌入式Neo4J DB 2.0.3上启动一批遍历。
Job正常运行一段时间（例如：1h）然后吞吐量急剧减慢，因为线程花费大部分时间等待锁定。
看起来内存缓冲区（MappedPersistenceWindow）不能被多个线程共享，这听起来有点奇怪。
来自线程转储的一些示例：
"taskExecutor-6" - Thread t@17
java.lang.Thread.State: BLOCKED
at java.lang.Object.wait(Native Method)
- waiting on <3a67f9f7> (a org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow)
at java.lang.Object.wait(Object.java:503)
at org.neo4j.kernel.impl.nioneo.store.LockableWindow.lock(LockableWindow.java:96)
at org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:197)
at org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:430)
at org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:84)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction$3.load(NeoStoreTransaction.java:208)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction$3.load(NeoStoreTransaction.java:198)
at org.neo4j.kernel.impl.nioneo.xa.RecordChanges.getOrLoad(RecordChanges.java:63)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.relLoadLight(NeoStoreTransaction.java:1189)
at org.neo4j.kernel.impl.persistence.PersistenceManager.loadLightRelationship(PersistenceManager.java:109)
at org.neo4j.kernel.impl.core.NodeManager$2.loadById(NodeManager.java:114)
at org.neo4j.kernel.impl.core.NodeManager$2.loadById(NodeManager.java:110)
at org.neo4j.kernel.impl.cache.AutoLoadingCache.get(AutoLoadingCache.java:93)
at org.neo4j.kernel.impl.core.NodeManager.getRelationshipForProxy(NodeManager.java:544)
at org.neo4j.kernel.InternalAbstractGraphDatabase$6.lookupRelationship(InternalAbstractGraphDatabase.java:849)
at org.neo4j.kernel.impl.core.RelationshipProxy.getType(RelationshipProxy.java:141)
"taskExecutor-5" - Thread t@16
java.lang.Thread.State: RUNNABLE
at org.neo4j.kernel.impl.nioneo.store.LockableWindow.markAsInUse(LockableWindow.java:70)
- locked <6abe6e1> (a org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow)
at org.neo4j.kernel.impl.nioneo.store.BrickElement.getAndMarkWindow(BrickElement.java:94)
at org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:147)
at org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:430)
at org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getChainRecord(RelationshipStore.java:325)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.getMoreRelationships(NeoStoreTransaction.java:2331)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.getMoreRelationships(NeoStoreTransaction.java:1390)
at org.neo4j.kernel.impl.persistence.PersistenceManager.getMoreRelationships(PersistenceManager.java:94)
at org.neo4j.kernel.impl.core.RelationshipLoader.getMoreRelationships(RelationshipLoader.java:50)
at org.neo4j.kernel.impl.core.NodeManager.getMoreRelationships(NodeManager.java:779)
at org.neo4j.kernel.impl.core.NodeImpl.loadMoreRelationshipsFromNodeManager(NodeImpl.java:577)
at org.neo4j.kernel.impl.core.NodeImpl.getMoreRelationships(NodeImpl.java:540)
- locked <2b29ed5b> (a org.neo4j.kernel.impl.core.NodeImpl)
at org.neo4j.kernel.impl.core.RelationshipIterator.fetchNextOrNull(RelationshipIterator.java:98)
at org.neo4j.kernel.impl.core.RelationshipIterator.fetchNextOrNull(RelationshipIterator.java:36)
at org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:55)
at org.neo4j.kernel.impl.core.NodeImpl.hasRelationship(NodeImpl.java:644)
at org.neo4j.kernel.impl.core.NodeProxy.hasRelationship(NodeProxy.java:183)
"taskExecutor-4" - Thread t@15
java.lang.Thread.State: BLOCKED
at java.lang.Object.wait(Native Method)
- waiting on <3a67f9f7> (a org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow)
at java.lang.Object.wait(Object.java:503)
at org.neo4j.kernel.impl.nioneo.store.LockableWindow.lock(LockableWindow.java:96)
at org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:197)
at org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:430)
at org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getChainRecord(RelationshipStore.java:325)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.getMoreRelationships(NeoStoreTransaction.java:2331)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.getMoreRelationships(NeoStoreTransaction.java:1390)
at org.neo4j.kernel.impl.persistence.PersistenceManager.getMoreRelationships(PersistenceManager.java:94)
at org.neo4j.kernel.impl.core.RelationshipLoader.getMoreRelationships(RelationshipLoader.java:50)
at org.neo4j.kernel.impl.core.NodeManager.getMoreRelationships(NodeManager.java:779)
at org.neo4j.kernel.impl.core.NodeImpl.loadMoreRelationshipsFromNodeManager(NodeImpl.java:577)
at org.neo4j.kernel.impl.core.NodeImpl.getMoreRelationships(NodeImpl.java:540)
- locked <41fe8c4f> (a org.neo4j.kernel.impl.core.NodeImpl)
at org.neo4j.kernel.impl.core.RelationshipIterator.fetchNextOrNull(RelationshipIterator.java:98)
at org.neo4j.kernel.impl.core.RelationshipIterator.fetchNextOrNull(RelationshipIterator.java:36)
at org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:55)
at org.neo4j.kernel.impl.core.NodeImpl.hasRelationship(NodeImpl.java:644)
at org.neo4j.kernel.impl.core.NodeProxy.hasRelationship(NodeProxy.java:183)
"taskExecutor-3" - Thread t@14
java.lang.Thread.State: WAITING
at java.lang.Object.wait(Native Method)
- waiting on <3a67f9f7> (a org.neo4j.kernel.impl.nioneo.store.MappedPersistenceWindow)
at java.lang.Object.wait(Object.java:503)
at org.neo4j.kernel.impl.nioneo.store.LockableWindow.lock(LockableWindow.java:96)
at org.neo4j.kernel.impl.nioneo.store.PersistenceWindowPool.acquire(PersistenceWindowPool.java:197)
at org.neo4j.kernel.impl.nioneo.store.CommonAbstractStore.acquireWindow(CommonAbstractStore.java:430)
at org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:84)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction$3.load(NeoStoreTransaction.java:208)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction$3.load(NeoStoreTransaction.java:198)
at org.neo4j.kernel.impl.nioneo.xa.RecordChanges.getOrLoad(RecordChanges.java:63)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreTransaction.relLoadLight(NeoStoreTransaction.java:1189)
at org.neo4j.kernel.impl.persistence.PersistenceManager.loadLightRelationship(PersistenceManager.java:109)
at org.neo4j.kernel.impl.core.NodeManager$2.loadById(NodeManager.java:114)
at org.neo4j.kernel.impl.core.NodeManager$2.loadById(NodeManager.java:110)
at org.neo4j.kernel.impl.cache.AutoLoadingCache.get(AutoLoadingCache.java:93)
at org.neo4j.kernel.impl.core.NodeManager.getRelationshipForProxy(NodeManager.java:544)
at org.neo4j.kernel.InternalAbstractGraphDatabase$6.lookupRelationship(InternalAbstractGraphDatabase.java:849)
at org.neo4j.kernel.impl.core.RelationshipProxy.getOtherNode(RelationshipProxy.java:108)
at org.neo4j.kernel.impl.traversal.TraversalBranchImpl.next(TraversalBranchImpl.java:145)
at org.neo4j.graphdb.traversal.PreorderDepthFirstSelector.next(PreorderDepthFirstSelector.java:49)
at org.neo4j.kernel.impl.traversal.MonoDirectionalTraverserIterator.fetchNextOrNull(MonoDirectionalTraverserIterator.java:68)
at org.neo4j.kernel.impl.traversal.MonoDirectionalTraverserIterator.fetchNextOrNull(MonoDirectionalTraverserIterator.java:35)
at org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:55)
有什么想法吗？