Apache CXF Jetty配置httpj：engine-factory ThrottlingFilter在高负载时返回HTTP 503

Question

我在Apache CXF JAX-RS的REST层中有以下Jetty服务器配置：

<httpj:engine-factory bus="cxf">
  <!--
    you just need to specify the TLS Server configuration for the certain port
  -->
  <httpj:engine port="${port}">
    <httpj:tlsServerParameters>
      <sec:keyManagers keyPassword="${keystorePassword}">
        <sec:keyStore type="JKS"
                      password="${keystorePassword}"
                      file="${keystoreFile}"/>
        </sec:keyManagers>
        <sec:trustManagers>
          <sec:keyStore type="JKS"
                        password="${keystorePassword}"
                        file="${bookshelf.portal.http.keystoreFile}"/>
      </sec:trustManagers>
    </httpj:tlsServerParameters>

    <httpj:threadingParameters minThreads="5"
                               maxThreads="15" />

    <httpj:sessionSupport>true</httpj:sessionSupport>
  </httpj:engine>
</httpj:engine-factory>

我想配置Jetty使用ThrottlingFilter在服务器上的高负载时抛出HTTP 503错误。

我该怎么做？