Accident description

SMS service is extracted separately to provide HTTP interface access. Load balancing is provided through haproxy

Occasionally in the log:

java.net.SocketException: Unexpected end of file from server
	at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:792)
	at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647)
	at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:789)
	at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1569)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)

At that time did not care too much, until the request SMS service is not available, to investigate the problem

Because the HTTP request code did not set the timeout, haproxy hung up the request and the whole service was unavailable

Exception code

 try {
            u = new URL(url);
            con = (HttpURLConnection) u.openConnection();
            con.setRequestMethod("POST");
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setUseCaches(false);
            con.setRequestProperty("Content-Type", "application/json");
            OutputStreamWriter osw = new OutputStreamWriter(con.getOutputStream(), "UTF-8");
            osw.write(msg);
            osw.flush();
            osw.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (con != null) {
                con.disconnect();
            }

        }

Restoration plan

**Add timeouts. All IO operations should add timeouts**

try {
            u = new URL(url);
            con = (HttpURLConnection) u.openConnection();
            con.setRequestMethod("POST");
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setUseCaches(false);
            con.setConnectTimeout(3000);
            con.setReadTimeout(3000);
            con.setRequestProperty("Content-Type", "application/json");
            OutputStreamWriter osw = new OutputStreamWriter(con.getOutputStream(), "UTF-8");
            osw.write(msg);
            osw.flush();
            osw.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (con != null) {
                con.disconnect();
            }

        }

Second, because the old code directly used the net package, I don’t think it’s very easy to use, so I directly upgraded to httpclient fluent

try {
            return Request.Post(url)
                    .useExpectContinue()
                    .version(HttpVersion.HTTP_1_1)
                    .bodyString(param, ContentType.APPLICATION_JSON)
                    .connectTimeout(3000)
                    .socketTimeout(3000)
                    .execute()
                    .returnContent()
                    .asString();
        } catch (IOException e) {
            LOGGER.error("request address:{},parameters:{}",url,param);
            LOGGER.error("Error in post request",e);
        }

POM dependency

            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>fluent-hc</artifactId>
                <version>4.5.3</version>
            </dependency>