java - 连接重置使用 REST 服务(scala/spray)

Question

我在向休息服务发送并发请求时遇到问题；客户端 (Apache JMeter) 中的消息是某些请求的“连接重置”，具体取决于请求数，例如，我发送 100 个请求并且服务器的响应 100% 成功，但是如果我发送 500 个请求，则 30 % 的响应是错误的。

java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(SocketInputStream.java:196)
    at java.net.SocketInputStream.read(SocketInputStream.java:122)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:166)
    at org.apache.http.impl.io.SocketInputBuffer.fillBuffer(SocketInputBuffer.java:90)
    at org.apache.http.impl.io.AbstractSessionInputBuffer.readLine(AbstractSessionInputBuffer.java:281)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:92)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:61)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:254)
    at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:289)
    at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:252)
    at org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:191)
    at org.apache.jmeter.protocol.http.sampler.MeasuringConnectionManager$MeasuredConnection.receiveResponseHeader(MeasuringConnectionManager.java:201)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:300)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:127)
    at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:715)
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:520)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
    at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.executeRequest(HTTPHC4Impl.java:517)
    at org.apache.jmeter.protocol.http.sampler.HTTPHC4Impl.sample(HTTPHC4Impl.java:331)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:74)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1146)
    at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1135)
    at org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:434)
    at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:261)
    at java.lang.Thread.run(Thread.java:745)

我修改了“application.conf”，内容如下:

spray.can {
  server {
    server-header = spray-can/${spray.version}
    ssl-encryption = off
    pipelining-limit = 16 
    idle-timeout = 60 s 
    request-timeout = 30 s
    timeout-timeout = 2 s
    timeout-handler = ""
    reaping-cycle = 250 ms
    stats-support = on
    remote-address-header = off
    raw-request-uri-header = off
    transparent-head-requests = on
    chunkless-streaming = off
    verbose-error-messages = on
    request-chunk-aggregation-limit = 1m
    response-header-size-hint = 512
    bind-timeout = infinite
    unbind-timeout = 1s
    registration-timeout = 1s
    default-host-header = ""
    automatic-back-pressure-handling = on
    back-pressure {
      noack-rate = 10
      reading-low-watermark = infinite
    }
    parsing = ${spray.can.parsing}
  }
  client {
    user-agent-header = spray-can/${spray.version}
    idle-timeout = 60 s
    request-timeout = 40 s 
    reaping-cycle = 250 ms
    response-chunk-aggregation-limit = 1m
    chunkless-streaming = off
    request-header-size-hint = 256 
    max-encryption-chunk-size = 1m
    connecting-timeout = 30s
    proxy {
      http = default
      https = default
    }
    ssl-tracing = off
    parsing = ${spray.can.parsing}
  }
  host-connector {
    max-connections = 80 
    max-retries = 8 
    max-redirects = 0
    pipelining = enabled
    idle-timeout = 30 s
    client = ${spray.can.client}
  }
}

JVM的设置是:

-Xms1024M
-Xmx2048M 
-Xss1M 
-XX:MaxPermSize=1024m

重要提示:由于业务逻辑，服务器支持并发事务是必要的；在不到 5 秒的时间内完成 500 个单独的连接(事务)。

Answer 1

您的timeout 设置看起来不错，每秒处理 500 个请求绝对不是问题。

很可能您的请求处理时间太长，即超过 request-timeout + timeout-timeout = 32 秒。你需要检查你的架构，看看它在哪里以及为什么花费这么多时间。这对于常规 Web 服务来说是非常不寻常的，其中大多数请求在毫秒范围内完成。如果你有一些繁重的处理，你必须做的时间比超时时间长，你可以回复 202 Accepted 并在后台进行处理。您可以返回一个 URI，客户端可以在其中检查请求的状态，或者使用回调到客户端或任何其他机制来传达请求已完成。

请记住不要阻塞路由本身，否则您会有效地阻塞所有其他请求并且您可能会遇到超时错误。例如，请参阅此答案:Use a Dispatcher with Spray HttpService .要实现非阻塞请求处理，请参见:How does spray.routing.HttpService dispatch requests? .

故障排除的一些想法:1) 测量处理单个请求所花费的时间，并查看它的扩展性 - 您是否存在资源争用？ 2) 检查您的网络和客户端不会导致超时 - 它们的超时应该高于服务器的。