无法解析 akka.pattern.AskTimeoutException：请求超时

Question

我正在尝试用 Apache Ignite 替换 OpenDaylight 中的默认 LevelDB，在更改 akka.conf 文件并部署我在此处找到的 akka-persistence-ignite jar 后，我无法执行此操作。 https://github.com/Romeh/akka-persistance-ignite

我在下面的源代码行 (AbstractDataStoreClientActor class) 中遇到一个问题，它抛出运行时异常。

   private static final Function1<ActorRef, ?> GET_CLIENT_FACTORY = ExplicitAsk.toScala(GetClientRequest::new);

   @SuppressWarnings("checkstyle:IllegalCatch")
   public static DataStoreClient getDistributedDataStoreClient(@Nonnull final ActorRef actor,
        final long timeout, final TimeUnit unit) {
        return (DataStoreClient) Await.result(ExplicitAsk.ask(actor, GET_CLIENT_FACTORY,
            Timeout.apply(timeout, unit)), Duration.Inf());

出现以下错误

akka.pattern.AskTimeoutException: Ask timed out on [Actor[akka://opendaylight-cluster-data/user/$a#-809157907]] after [30000 ms]. Sender[null] sent message of type "org.opendaylight.controller.cluster.databroker.actors.dds.GetClientRequest".

我的问题是我如何知道上述消息发送到的参与者的行为？有什么方法可以检查演员是否已正确创建？ Ask 方法超时的原因可能是什么？

EDIT::::: 来自 karaf.log

的错误堆栈跟踪

2018-07-12T11:27:01,755 | ERROR | opendaylight-cluster-data-akka.actor.default-dispatcher-18 | DistributedDataStoreClientActor  | 90 - com.typesafe.akka.slf4j - 2.5.11 | Persistence failure when replaying events for persistenceId [member-1-frontend-datastore-config]. Last known sequence number [0]
java.lang.NullPointerException: null
    at akka.japi.Util$.option(JavaAPI.scala:271) ~[84:com.typesafe.akka.actor:2.5.11]
    at akka.persistence.snapshot.japi.SnapshotStore.$anonfun$loadAsync(SnapshotStore.scala:20) ~[87:com.typesafe.akka.persistence:2.5.11]
    at scala.util.Success.$anonfun$map(Try.scala:251) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.util.Success.map(Try.scala:209) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.concurrent.Future.$anonfun$map(Future.scala:288) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.concurrent.impl.Promise.liftedTree1(Promise.scala:29) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.concurrent.impl.Promise.$anonfun$transform(Promise.scala:29) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:60) ~[323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:55) ~[84:com.typesafe.akka.actor:2.5.11]
    at akka.dispatch.BatchingExecutor$BlockableBatch.$anonfun$run(BatchingExecutor.scala:91) ~[84:com.typesafe.akka.actor:2.5.11]
    at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12) [323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:81) [323:org.scala-lang.scala-library:2.12.5.v20180316-130912-VFINAL-30a1428]
    at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:91) [84:com.typesafe.akka.actor:2.5.11]
    at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40) [84:com.typesafe.akka.actor:2.5.11]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:?]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:?]
    at java.lang.Thread.run(Thread.java:748) [?:?]

Answer 1

问题不在于 DistributedDatastoreClientActor - 它是持久性后端问题的副作用 - 请参阅我之前的评论。请注意，错误堆栈跟踪包含一个源自 akka.persistence.snapshot.japi.SnapshotStore 的 NPE，它指示支持 SnapshotStore 意外地从 loadAsync 返回 null。这指向 ignite 插件。

无法解析 akka.pattern.AskTimeoutException：请求超时

Unable to resolve akka.pattern.AskTimeoutException: Ask timed out

akka

opendaylight

akka-persistence