在暴风雨中使用Apache的AsyncHttpClient [英] using Apache's AsyncHttpClient in a storm bolt

问题描述

我有一个螺栓正在为每个元组进行API调用（HTTP Get）。
以避免需要等待响应，我当时想要使用apache HttpAsyncClient。

I have a bolt that is making an API call (HTTP Get) for every tuple. to avoid the need to wait for the response, I was looking to use the apache HttpAsyncClient.

在使用bolt的prepare方法实例化客户端之后，执行方法从元组构造URL并调用sendAsyncGetRequest（url）：

after instantiating the client in the bolt's prepare method, the execute method constructs the URL from the tuple and calls sendAsyncGetRequest(url):

private void sendAsyncGetRequest(String url){

    httpclient.execute(new HttpGet(url), new FutureCallback<HttpResponse>() {

        @Override
        public void completed(HttpResponse response) {
            LOG.info("Response Code : " + response.getStatusLine());
            LOG.debug(response.toString());
        }

        @Override
        public void failed(Exception ex) {
            LOG.warn("Async http request failed!", ex);
        }

        @Override
        public void cancelled() {
            LOG.warn("Async http request canceled!");
        }
    });
}

拓扑部署但Storm UI显示错误：

the topology deploys but the Storm UI shows an error:

java.lang.RuntimeException: java.lang.IllegalStateException: Request cannot be executed; I/O reactor status: STOPPED at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:12

推荐答案

您是否在回调可以执行之前关闭主流中的客户端（client.close（）;）？

Are you shutting down the client (client.close();) in your main flow before the callback can execute?

错误是说IO路径已经关闭。通常，异步客户端的实例应该重复用于重复请求，并且仅在发出ALL请求时销毁，例如在应用程序关闭时。

The error is saying that the IO path has already been closed. In general, instances of async clients should be re-used for repeated requests and destroyed only when "ALL" requests have been made, e.g. at application shutdown.

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