如何有效地重用 HttpClient 连接？

Question

我非常频繁地 (>= 1/秒) 对 API 端点执行 HTTP POST，并且我想确保我正在高效地执行此操作。我的目标是尽快成功或失败，特别是因为我有单独的代码来重试失败的 POST。 HttpClient performance tips 有一个不错的页面，但我不确定详尽实施它们是否会带来真正的好处。这是我现在的代码：

public class Poster {
  private String url;
  // re-use our request
  private HttpClient client;
  // re-use our method
  private PostMethod method;

  public Poster(String url) {
    this.url = url;

    // Set up the request for reuse.
    HttpClientParams clientParams = new HttpClientParams();
    clientParams.setSoTimeout(1000);  // 1 second timeout.
    this.client = new HttpClient(clientParams);
    // don't check for stale connections, since we want to be as fast as possible?
    // this.client.getParams().setParameter("http.connection.stalecheck", false);

    this.method = new PostMethod(this.url);
    // custom RetryHandler to prevent retry attempts
    HttpMethodRetryHandler myretryhandler = new HttpMethodRetryHandler() {
      public boolean retryMethod(final HttpMethod method, final IOException exception, int executionCount) {
        // For now, never retry
        return false;
      }
    };

    this.method.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, myretryhandler);
  }

  protected boolean sendData(SensorData data) {
    NameValuePair[] payload = {
      // ...
    };
    method.setRequestBody(payload);

    // Execute it and get the results.
    try {
      // Execute the POST method.
      client.executeMethod(method);
    } catch (IOException e) {
      // unable to POST, deal with consequences here
      method.releaseConnection();
      return false;
    }

    // don't release so that it can be reused?
    method.releaseConnection();

    return method.getStatusCode() == HttpStatus.SC_OK;
  }
}

禁用过时连接检查是否有意义？我应该考虑使用MultiThreadedConnectionManager 吗？当然，实际的基准测试会有所帮助，但我想先检查我的代码是否在正确的轨道上。

Answer 1

http 连接的大部分性能损失是建立套接字连接。您可以通过使用“keep-alive”http 连接来避免这种情况。为此，最好使用 HTTP 1.1 并确保始终在请求和响应中设置“Content-Length: xx”，并在适当时正确设置“连接：关闭”，并在收到时正确执行。