akka http，singleRequest（java），请求未发送

Question

我或多或少是akka和akka-http的新手，并且从演员发送http singleRequest时遇到问题。

我要完成的工作：

• 参与者在收到计算命令后计算值
• 一旦完成另一个演员的计算，就叫他ReplyActor ，它被调用来向另一个系统发送“完成的” http请求
• 消息正在排队，在我的设置中始终只有一个ReplyActor处于活动状态

如果我要发送一个计算单，一切正常。 如果某个时间点有10个计算顺序 ，则取决于是否由于调试消息而使系统变慢了多少，则不会发送请求。 注意，没有例外，没有超时。

我的actor设置的设计类似于akka示例中的分布式master worker示例。 在尝试找出问题出在哪里时，我只运行一个工作程序（ CalculationActor和ReplyActor ）。

好吧，我为您提供了更多详细信息。

首先，如果请求端点是用akka http编写的，那么一切也都可以正常工作。 可悲的是，它是用sparkjava编写的，它依赖码头。 但据我所知，这不是端点的错。 该请求未发送。

在akka.http.impl.engine.client.PoolConductor＃apply上是命令流图：

Request-   +-----------+     +-----------+    Switch-    +-------------+     +-----------+    Command
Context    |   retry   |     |   slot-   |    Command    |   doubler   |     |   route   +-------------->
+--------->|   Merge   +---->| Selector  +-------------->| (MapConcat) +---->|  (Flexi   +-------------->
           |           |     |           |               |             |     |   Route)  +-------------->
           +----+------+     +-----+-----+               +-------------+     +-----------+       to slots
                ^                  ^
                |                  | SlotEvent
                |             +----+----+
                |             | flatten | mapAsync
                |             +----+----+
                |                  | RawSlotEvent
                | Request-         |
                | Context     +---------+
                +-------------+  retry  |<-------- RawSlotEvent (from slotEventMerge)
                              |  Split  |
                              +---------+

未发送的请求缺少slot-Selector命令。 不知道为什么。 我已经花了一些时间进行调试。 也许以下是某种帮助：

成功发送的请求的命令链：

akka.stream.actor.ActorPublisher#onNext
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@1c81ab77),0)
    threadId: 51
akka.stream.actor.ActorPublisher#onNext
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@1c81ab77),0)
    threadId: 51
akka.stream.stage.GraphStageLogic#grab (fast path)
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@1c81ab77),0)
    threadId: 49
akka.stream.stage.GraphStageLogic#emit (isAvailable(out)) => push
    out (class): akka.stream.Outlet
    element (class): akka.http.impl.engine.client.PoolFlow$RequestContext
    threadId: 49
akka.stream.stage.GraphStageLogic#grab (fast path)
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@1c81ab77),0)
    threadId: 49
akka.stream.stage.GraphStageLogic#emit (isAvailable(out)) => push
    out (cass): akka.stream.Outlet
    element (class): akka.http.impl.engine.client.PoolConductor$SwitchSlotCommand)
    threadId: 49
akka.stream.stage.GraphStageLogic#emit (isAvailable(out)) => push
    out (class): akka.stream.Outlet
    element (class): akka.http.impl.engine.client.PoolConductor$DispatchCommand
    threadId: 49
akka.stream.actor.ActorPublisher#onNext
    HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1))
    threadId: 78
akka.stream.actor.ActorPublisher#onNext
    HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"acbacca1-11e1-4f14-a4a6-4b14b53598a4"),HttpProtocol(HTTP/1.1))
    threadId: 78
akka.stream.stage.GraphStageLogic#emit (isAvailable(out)) => push
    out (class): akka.stream.Outlet
    element (class): akka.http.impl.engine.rendering.RequestRenderingContext
    threadId: 78
akka.stream.stage.GraphStageLogic#emit (isAvailable(out)) => push
    out (class): akka.stream.Outlet
    element (class): scala.collection.immutable.$colon$colon
    threadId: 78
akka.stream.actor.ActorPublisher#onNext
    List(ResponseDelivery(ResponseContext(RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567), ...
    threadId: 78

未发送的请求的命令链（相同的运行）：

akka.stream.actor.ActorPublisher#onNext
    RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"47bc9378-5166-4a14-920a-8eab53717263"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@29ee365f),0)
    threadId: 116
akka.stream.actor.ActorPublisher#onNext
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"47bc9378-5166-4a14-920a-8eab53717263"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@29ee365f),0)
    threadId: 116
akka.stream.stage.GraphStageLogic#grab (fast path)
    element: RequestContext(HttpRequest(HttpMethod(POST),/example/reply/uri,List(Host: localhost:4567),HttpEntity.Strict(application/json,"47bc9378-5166-4a14-920a-8eab53717263"),HttpProtocol(HTTP/1.1)),List(scala.concurrent.impl.CallbackRunnable@29ee365f),0)
    threadId: 78
akka.stream.stage.GraphStageLogic#emit (NOT isAvailable(out)) => setOrAddEmitting
    out (class): akka.stream.Outlet
    element (class): akka.http.impl.engine.client.PoolFlow$RequestContext
    threadId: 78
akka.stream.stage.GraphStageLogic#emit (NOT isAvailable(out)) => setOrAddEmitting
    out (class): akka.stream.Outlet
    element (class): akka.http.impl.engine.client.PoolFlow$RequestContext
    threadId: 78
akka.stream.stage.GraphStageLogic#setOrAddEmitting case e
    handler: akka.stream.stage.GraphStageLogic$EagerTerminateOutput$@546413bd
    out: MergePreferred.out,
    next: akka.stream.stage.GraphStageLogic$EmittingSingle@69621de0
    threadId: 78
akka.stream.stage.GraphStageLogic#setOrAddEmitting case e
    handler: akka.stream.stage.GraphStageLogic$EagerTerminateOutput$@546413bd
    out: MergePreferred.out,
    next: akka.stream.stage.GraphStageLogic$EmittingSingle@69621de0
    threadId: 78
akka.stream.stage.GraphStageLogic#setOrAddEmitting case _
    handler: akka.stream.stage.GraphStageLogic$EagerTerminateOutput$@546413bd
    out: MergePreferred.out
    next: akka.stream.stage.GraphStageLogic$EmittingSingle@69621de0
    threadId: 78
akka.stream.actor.ActorPublisher#onNext
    element: List(Disconnected(0,0))
    threadId: 117
akka.stream.actor.ActorPublisher#onNext
    element: List(Disconnected(0,0))
    threadId: 117
akka.stream.actor.ActorPublisher#onNext
    element: List(Disconnected(1,0))
    threadId: 49

感谢您的帮助。 谢谢！

版本是2.4.8（2.11）（akka-actor，akka-http-core，akka-http-experimental，akka-stream）

Answer 1

得到它了！ 看起来我的请求做错了。

在〜4个请求后失败：

Http http = Http.get(context().system());
ActorMaterializer materializer = ActorMaterializer.create(context().system());
HttpRequest request = HttpRequestPOST("http://localhost:8091").withEntity(ContentTypes.APPLICATION_JSON, message);

http.singleRequest(request, materializer).whenComplete((r, t) -> log.info("httpResponse: {}, throwable: {}", r, t));

作品：

Http http = Http.get(context().system());
ActorMaterializer materializer = ActorMaterializer.create(context().system());
Flow<HttpRequest, HttpResponse, CompletionStage<OutgoingConnection>> flow = http.outgoingConnection(ConnectHttp.toHost("localhost", 8091));
HttpRequest request = HttpRequest.POST("http://localhost:8091").withEntity(ContentTypes.APPLICATION_JSON, message);

Source.single(request).via(flow).runWith(Sink.head(), materializer).whenComplete((r, t) -> log.info("httpResponse: {}, throwable: {}", r, t));

非常感谢这个问题（和答案） ，它为我指明了正确的方向。