HttpClient Timeout

Configure Timeouts via Raw String Parameters

DefaultHttpClient httpClient = new DefaultHttpClient();
int timeout = 5; // seconds
HttpParams httpParams = httpClient.getParams();
httpParams.setParameter(
  CoreConnectionPNames.CONNECTION_TIMEOUT, timeout * 1000);
httpParams.setParameter(
  CoreConnectionPNames.SO_TIMEOUT, timeout * 1000);
httpParams.setParameter(
  ClientPNames.CONN_MANAGER_TIMEOUT, new Long(timeout * 1000));

Configure Timeouts via the API

DefaultHttpClient httpClient = new DefaultHttpClient();
int timeout = 5; // seconds
HttpParams httpParams = httpClient.getParams();
HttpConnectionParams.setConnectionTimeout(
  httpParams, timeout * 1000); // http.connection.timeout
HttpConnectionParams.setSoTimeout(
  httpParams, timeout * 1000); // http.socket.timeout

Configure Timeouts Using the New 4.3. Builder

int timeout = 5;
RequestConfig config = RequestConfig.custom()
  .setConnectTimeout(timeout * 1000)
  .setConnectionRequestTimeout(timeout * 1000)
  .setSocketTimeout(timeout * 1000).build();
CloseableHttpClient client = 
  HttpClientBuilder.create().setDefaultRequestConfig(config).build();

That is the recommended way of configuring all three timeouts in a type-safe and readable manner.

Timeout Properties Explained

Now, let’s explain what these various types of timeouts mean:

• the Connection Timeout (http.connection.timeout) – the time to establish the connection with the remote host

• the Socket Timeout (http.socket.timeout) – the time waiting for data – after establishing the connection; maximum time of inactivity between two data packets

• the Connection Manager Timeout (http.connection-manager.timeout) – the time to wait for a connection from the connection manager/pool

Hard Timeout

While setting timeouts on establishing the HTTP connection and not receiving data is very useful, sometimes we need to set a hard timeout for the entire request.

HttpGet getMethod = new HttpGet(
  "http://localhost:8080/httpclient-simple/api/bars/1");
int hardTimeout = 5; // seconds
TimerTask task = new TimerTask() {
    @Override
    public void run() {
        if (getMethod != null) {
            getMethod.abort();
        }
    }
};
new Timer(true).schedule(task, hardTimeout * 1000);
HttpResponse response = httpClient.execute(getMethod);
System.out.println(
  "HTTP Status of response: " + response.getStatusLine().getStatusCode());

Timeout and DNS Round Robin

It’s quite common that some larger domains will be using a DNS round robin configuration – essentially having the same domain mapped to multiple IP addresses.

int timeout = 3;
RequestConfig config = RequestConfig.custom().
  setConnectTimeout(timeout * 1000).
  setConnectionRequestTimeout(timeout * 1000).
  setSocketTimeout(timeout * 1000).build();
CloseableHttpClient client = HttpClientBuilder.create()
  .setDefaultRequestConfig(config).build();
HttpGet request = new HttpGet("http://www.google.com:81");
response = client.execute(request);

Results

• HttpClientTimeoutTest

References

• HttpClient Timeout