CODEWITHSUNDEEP
javamultithreadingsocketshttphttpurlconnection
user1510335
user1510335

Reputation: 1

java.net.SocketException: Socket Closed eventhough input and output streams are closed after read, write

I'm running multi threaded java application where below method will be executed by many threads(about 300) in parallel. And i see this exception only when thread count is more but not when thread count is less than 50. I read few posts in stackoverflow and code looks in complaints to what posts described. Any help would be appreciated. Thanks in advance.

Here is my method: 

public static String invokeWebService(String request, String fwfmId, BatchVO batchVO){
    String responseString = "";
    //log the request string
    Logger_trace.info("Service request for input "+ fwfmId +":: "+CommonUtil.removeCrLf(request));
    try {
            URL url = new URL(batchVO.getWebServiceUrl());
            HttpURLConnection  urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("POST");
            urlConnection.setRequestProperty("Content-type", "text/xml; charset=utf-8");

            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.setConnectTimeout(Integer.parseInt(batchVO.getConnectionTimeOut()));
            urlConnection.setReadTimeout(Integer.parseInt(batchVO.getReadTimeOut()));
            OutputStream outputStream = urlConnection.getOutputStream();
            outputStream.write(request.getBytes());
            outputStream.flush();

            //get response form input stream and convert into string
            InputStreamReader inputStreamReader = new InputStreamReader(urlConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String inputLine;
            StringBuffer response = new StringBuffer();

            while ((inputLine = bufferedReader.readLine()) != null) {
                response.append(inputLine);
            }

            responseString = response.toString();

            //close resources
            bufferedReader.close();
            inputStreamReader.close();
            outputStream.close(); 

            //log the response string
            logger_trace.info("Service response for input "+ fwfmId +":: "+ CommonUtil.removeCrLf(responseString));

            //Update Database columns
            updateRecordInTable(request, responseString, fwfmId, batchVO.getDataSource(), batchVO.getBatchId());    

        } catch (SocketConnectException e) {
            logger_trace.error("WebserviceHandler.invokeWebService : SocketConnectException block : "+fwfmId +" ", e);
            updateRecordInTableWithTimeout(fwfmId, batchVO.getDataSource(), batchVO.getBatchId());
        } catch (SocketTimeoutException e) {
            logger_trace.error("WebserviceHandler.invokeWebService : SocketTimeoutException block : "+ fwfmId+" ", e);
            updateRecordInTableWithTimeout(fwfmId, batchVO.getDataSource(), batchVO.getBatchId());
        } catch (MalformedURLException e) {
            logger_trace.error("WebserviceHandler.invokeWebService : MalformedURLException block : ", e);
        } catch (IOException e) {
            logger_trace.error("WebserviceHandler.invokeWebService : IOException block : ", e);
        } catch(Exception e){
            logger_trace.error("WebserviceHandler.invokeWebService : General Exception block : ", e);
        }
        return responseString;
    }

Exception: 

 [ERROR] 2017-10-31 03:18:54,435 [main] TRACE -
 WebserviceHandler.invokeWebService : IOException block : 
 java.net.SocketException: Socket Closed
         at java.net.AbstractPlainSocketImpl.setOption(AbstractPlainSocketImpl.java:212)
 ~[?:1.8.0_131]
         at java.net.Socket.setTcpNoDelay(Socket.java:980) ~[?:1.8.0_131]
         at weblogic.net.http.HttpClient.openServer(HttpClient.java:411)
 ~[wlfullclient.jar:12.2.2.0.0]
         at weblogic.net.http.HttpClient.openServer(HttpClient.java:511)
 ~[wlfullclient.jar:12.2.2.0.0]
         at weblogic.net.http.HttpClient.New(HttpClient.java:313) ~[wlfullclient.jar:12.2.2.0.0]
         at weblogic.net.http.HttpURLConnection.getHttpClient(HttpURLConnection.java:314)
 ~[wlfullclient.jar:12.2.2.0.0]
         at weblogic.net.http.HttpURLConnection.getInputStream(HttpURLConnection.java:760)
 ~[wlfullclient.jar:12.2.2.0.0]
         at weblogic.net.http.SOAPHttpURLConnection.getInputStream(SOAPHttpURLConnection.java:41)
 ~[wlfullclient.jar:12.2.2.0.0]
         at ca.bell.webservice.WebServiceHandler.invokeWebService(WebServiceHandler.java:56)
 [MigrationTool.jar:?]
         at ca.bell.webservice.ExecuteMigrationWork.performRun(ExecuteMigrationWork.java:40)
 [MigrationTool.jar:?]
         at ca.bell.workmanagement.work.Work.call(Work.java:155) [MigrationTool.jar:?]
         at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_131]
         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
 [?:1.8.0_131]
         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
 [?:1.8.0_131]
         at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]

Upvotes: 0

Views: 844

Answers (1)

Alexandre Dupriez
Alexandre Dupriez

Reputation: 3036

Interesting. Let's start with an analysis of your stack trace, starting from the closest source of the exception. From the source code of AbstractPlainSocketImpl, the first precondition enforced is:

public void setOption(int opt, Object val) throws SocketException {
  if (isClosedOrPending()) {
    throw new SocketException("Socket Closed");
  }
...

Since the scope of your HttpURLConnection is limited to the method invokeWebService, we can rule out the hypothesis of a concurrent action on the socket, and since seems fine method and hasn't closed the socket, I would believe that isClosedOrPending returns true because the socket's file descriptor is null:

public boolean isClosedOrPending() {
    /*
     * Lock on fdLock to ensure that we wait if a
     * close is in progress.
     */
    synchronized (fdLock) {
        if (closePending || (fd == null)) {
            return true;
        } else {
            return false;
        }
    }
}

What is questionable in this analysis is why the fd file descriptor is null. However, this is not really important at this stage. Should we believe in our assumptions, one conclusion we could draw is that you are creating too many connections for your system to handle.

How do we solve this? Here we need to step back a little and see if we can refactor the code to limit the number of concurrent connections. I would need much more details about your specific implementation to narrow down the design candidates which are otherwise boundless. For instance, would a connection pool be appropriate? Should we implement back-pressure and throttle the clients? Should we scale horizontally and distribute the load?

Upvotes: 1

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