JanusGraph 图片在查询超时后停止响应，如何防止？

Question

当 JanusGraph 服务器超过他的“evaluationTimeout”时，服务器停止响应

我正在使用默认的 docker 镜像 janusgraph/janusgraph:latest（Berkeley 和 Lucene） 并与 gremlin 控制台连接

在第一次超时协议之后，在获得相同响应之前有效的查询：

Evaluation exceeded the configured 'evaluationTimeout' threshold of 30000 ms or evaluation was otherwise cancelled directly for request [g.V().limit(4).valueMap()]: null - try increasing the timeout with the :remote command

服务器错误：

java.util.concurrent.TimeoutException: Evaluation exceeded the configured 'evaluationTimeout' threshold of 30000 ms or evaluation was otherwise cancelled directly for request [g.V()]
        at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.lambda$eval$1(GremlinExecutor.java:316)
        at io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
        at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:170)
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:164)
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:500)
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at java.lang.Thread.run(Thread.java:748)
1318978 [pool-6-thread-1] WARN  org.janusgraph.diskstorage.log.kcvs.KCVSLog  - Could not read messages for timestamp [2020-05-24T10:12:30.449Z] (this read will be retried)
org.janusgraph.core.JanusGraphException: Could not execute operation due to backend exception
        at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:56)
        at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:158)
        at org.janusgraph.diskstorage.log.kcvs.KCVSLog$MessagePuller.run(KCVSLog.java:725)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: org.janusgraph.diskstorage.PermanentBackendException: Could not start BerkeleyJE transaction
        at org.janusgraph.diskstorage.berkeleyje.BerkeleyJEStoreManager.beginTransaction(BerkeleyJEStoreManager.java:163)
        at org.janusgraph.diskstorage.berkeleyje.BerkeleyJEStoreManager.beginTransaction(BerkeleyJEStoreManager.java:47)
        at org.janusgraph.diskstorage.keycolumnvalue.keyvalue.OrderedKeyValueStoreManagerAdapter.beginTransaction(OrderedKeyValueStoreManagerAdapter.java:68)
        at org.janusgraph.diskstorage.log.kcvs.KCVSLog.openTx(KCVSLog.java:319)
        at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:145)
        at org.janusgraph.diskstorage.util.BackendOperation$1.call(BackendOperation.java:161)
        at org.janusgraph.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:68)
        at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:54)
        ... 9 more
Caused by: com.sleepycat.je.ThreadInterruptedException: (JE 18.3.12) Environment must be closed, caused by: com.sleepycat.je.ThreadInterruptedException: Environment invalid because of previous exception: (JE 18.3.12) /var/lib/janusgraph/data java.lang.InterruptedException THREAD_INTERRUPTED: InterruptedException may cause incorrect internal state, unable to continue. Environment is invalid and must be closed.
        at com.sleepycat.je.ThreadInterruptedException.wrapSelf(ThreadInterruptedException.java:105)
        at com.sleepycat.je.dbi.EnvironmentImpl.checkIfInvalid(EnvironmentImpl.java:1835)
        at com.sleepycat.je.dbi.EnvironmentImpl.checkOpen(EnvironmentImpl.java:1844)
        at com.sleepycat.je.Environment.checkOpen(Environment.java:2697)
        at com.sleepycat.je.Environment.beginTransactionInternal(Environment.java:1409)
        at com.sleepycat.je.Environment.beginTransaction(Environment.java:1383)
        at org.janusgraph.diskstorage.berkeleyje.BerkeleyJEStoreManager.beginTransaction(BerkeleyJEStoreManager.java:146)
        ... 16 more
Caused by: com.sleepycat.je.ThreadInterruptedException: Environment invalid because of previous exception: (JE 18.3.12) /var/lib/janusgraph/data java.lang.InterruptedException THREAD_INTERRUPTED: InterruptedException may cause incorrect internal state, unable to continue. Environment is invalid and must be closed.
        at com.sleepycat.je.latch.LatchImpl.acquireExclusive(LatchImpl.java:67)
        at com.sleepycat.je.tree.IN.latch(IN.java:547)
        at com.sleepycat.je.dbi.CursorImpl.latchBIN(CursorImpl.java:402)
        at com.sleepycat.je.dbi.CursorImpl.cloneCursor(CursorImpl.java:230)
        at com.sleepycat.je.Cursor.beginMoveCursor(Cursor.java:5252)
        at com.sleepycat.je.Cursor.beginMoveCursor(Cursor.java:5259)
        at com.sleepycat.je.Cursor.retrieveNextNoDups(Cursor.java:3550)
        at com.sleepycat.je.Cursor.retrieveNext(Cursor.java:3312)
        at com.sleepycat.je.Cursor.getInternal(Cursor.java:1313)
        at com.sleepycat.je.Cursor.get(Cursor.java:1244)
        at com.sleepycat.je.Cursor.getNext(Cursor.java:1512)

Answer 1

此 JanusGraph 问题解释了有关 TinkerPop 测​​试套件的遍历中断的问题：

https://github.com/JanusGraph/janusgraph/issues/171

由于 Berkeley JE 不支持中断（请参阅 BerkeleyJEStoreManager 和 Berkeley JE FAQ），因此该套件运行后所有测试中都会出现内部状态错误。

TinkerPop 进行中断测试的一个原因是，它验证 Gremlin Server 可以使用该中断函数成功取消基于服务器的遍历。看起来伯克利根本无法支持这一点。您需要使用不同的 JanusGraph 后端。

Answer 2

我们不想替换伯克利 JE

所以我们最终使用强制索引来解决问题。

janusgraph.query.force-index: true