scala - 由于SSL连接已经关闭，如何解决Droping Close的错误

Question

我正在调用API，但是大多数时候我总是收到错误消息:“正在关闭，因为SSL连接已经在关闭”和“过早关闭(服务器似乎不支持请求)管道)。”像90％的时间一样，我得到了该错误，这意味着:在极少数情况下，查询确实会返回其应有的数据。

为了确保这不是API的服务器问题，我使用Node.js(Express和Request库)复制了相同的查询，并且每次都可以使用。这几乎使我确定是喷虫。

这是代码的示例:

case class MyClass(user: String, pass: String)

class MyActor extends Actor {
  import spray.client.pipelining._
  import spray.http.BasicHttpCredentials
  import spray.http.{HttpRequest,HttpResponse}
  import scala.concurrent.Future

  import context.dispatcher

  def receive = {
    case myClass: MyClass => {
      val credentials: BasicHttpCredentials = BasicHttpCredentials(myClass.user, myClass.pass)
      val url: String = "https://myApi?params=values"
      val request: HttpRequest = Get(url) ~> addCredentials(credentials)
      val pipeline = sendReceive
      val response: Future[HttpResponse] = pipeline(request)
      val finalRes: Future[String] = response.map{ r =>
        println(r)
        r.entity.asString
      }
      finalRes pipeTo sender
    }
  } // end receive
} //end Actor

错误详细信息:

04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-8] a.i.TcpOutgoingConnection - Attempting connection to ...
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-6] a.i.TcpOutgoingConnection - Connection established to ...
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-6] s.c.c.HttpClientConnection - Connected to ...
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-9] s.c.c.HttpHostConnectionSlot - Connection to ... established, dispatching 1 pending requests
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpClientConnection - now monitoring Actor[akka://on-spray-can/system/IO-TCP/selectors/$a/5]
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-6] s.c.c.HttpHostConnectionSlot - Dispatching GET request to /api?params=values across connection Actor[akka://on-spray-can/user/IO-HTTP/group-0/4]
04/01 10:19:05 DEBUG[on-spray-can-akka.actor.default-dispatcher-6] s.c.c.HttpHostConnectionSlot - now monitoring Actor[akka://on-spray-can/user/IO-HTTP/group-0/4]
04/01 10:19:06 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpClientConnection - Dropping Close since the SSL connection is already closing
04/01 10:19:06 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpClientConnection - Connection was PeerClosed, awaiting TcpConnection termination...
04/01 10:19:06 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] a.i.TcpOutgoingConnection - stopped
04/01 10:19:06 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpClientConnection - TcpConnection terminated, stopping
04/01 10:19:06 WARN [on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpHostConnectionSlot - Premature connection close (the server doesn't appear to support request pipelining) in response to GET request to /myApi?params=values with 1 retries left, retrying...
04/01 10:19:06 DEBUG[on-spray-can-akka.actor.default-dispatcher-3] s.c.c.HttpClientConnection - stopped

并且我能够在所有这些版本中重现该错误:

spray 1.0.1; akka 2.0.5; scala 2.9.3
spray 1.2.1; akka 2.2.4; scala 2.10.1
spray 1.3.1; akka 2.3.0; scala 2.10.3
spray 1.3.2; akka 2.3.6; scala 2.11.4
spray 1.3.3; akka 2.3.9; scala 2.11.6

Answer 1

如你所说，

To make sure this wasn’t the API’s server issue, I replicate the same query using Node.js (Express and Request libs) and it works every time. It makes me almost sure is a spray bug.

您在Scala中的代码使用HTTP管道功能发送请求，在使用Node.js测试时是否通过HTTP管道功能发送请求？

对于错误消息:

the server doesn't appear to support request pipelining

您应确保:

请确保服务器支持流水线功能，并且启用了流水线功能。

如果客户端和服务器(包括反向代理)之间存在代理，请确保代理支持流水线功能，并且启用了流水线功能。

如果不能确保可以正确支持流水线功能，则不应使用它。

以下资源可能会有所帮助:

HTTP pipelining requires both the client and the server to support it. HTTP/1.1 conforming servers are required to support pipelining. This does not mean that servers are required to pipeline responses, but that they are required not to fail if a client chooses to pipeline requests.[7]

https://en.wikipedia.org/wiki/HTTP_pipelining

HTTP pipelining is not activated by default in modern browsers:

Buggy proxies are still common and these lead to strange and erratic behaviors that Web developers cannot foresee and diagnose easily. Pipelining is complex to implement correctly: the size of the resource being transferred, the effective RTT that will be used, as well as the effective bandwidth, have a direct incidence on the improvement provided by the pipeline. Without knowing these, important messages may be delayed behind unimportant ones. The notion of important even evolves during page layout! HTTP pipelining therefore brings a marginal improvement in most cases only. Pipelining is subject to the HOL problem. For these reasons, pipelining has been superseded by a better algorithm, multiplexing, that is used by HTTP/2.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Connection_management_in_HTTP_1.x $ revision / 1330814