HttpUrlConnection 在 CentOS 上运行时占用 100% CPU

Question

我有一个 HttPURLConnection 程序，它正在与运行在同一台机器（在本例中为 CentOS）上但部署在其他一些 tomcat 服务器上的某个应用程序建立连接。这意味着部署在不同 tomcat 上的两个应用程序之间会建立一个 HttpConnection，其中两个 tomcat 都在同一台机器上运行。

一切正常，当我发出一个请求时，我在 200 英里内得到了响应。 但是，当应用程序通过 JMeter 加载 100 个并行运行的请求以进行无限循环时，应用程序开始占用高 CPU 处理能力。

这是我的代码：

public String sendHttpGetReq(String urlParameters,String msisdn, InNodeConfig inNodeConfig, InNodeDetails inNodeDetails)
{
    Logger.sysLog(LogValues.info, this.getClass().getName(),"["+msisdn+"] Inside sendHttpGetReq");
    String response = "";
    //response =  "{\"id\":\"584371732\",\"status_billing\":\"INSUFFICIENT_FUNDS\",\"status_sms\":\"NO_SMS\"}";
    String url = "";
    URL obj = null;
    HttpURLConnection con = null;
    try
    {
        url = "http://"+inNodeConfig.getServerIp()+":"+inNodeConfig.getServerPort()+inNodeConfig.getServiceUri();
        url = url+urlParameters;
        Logger.sysLog(LogValues.info, this.getClass().getName(),"["+msisdn+"] url = "+url);
        obj = new URL(url);
        con = (HttpURLConnection) obj.openConnection();     

        con.setDoOutput(true);
        con.setRequestMethod("GET");
        con.setConnectTimeout(Integer.parseInt(inNodeConfig.getConTimeOut()));
        con.setReadTimeout(Integer.parseInt(inNodeConfig.getConTimeOut())+1000);

        int responseCode = con.getResponseCode();
        Logger.sysLog(LogValues.info, this.getClass().getName(),"["+msisdn+"] HTTP Response Code : " + responseCode);
        Logger.sysLog(LogValues.info, this.getClass().getName(),"["+msisdn+"] HTTP Response message : " + con.getResponseMessage());

        if(responseCode == 202 || responseCode == 200)
        {   
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuffer responseBf = new StringBuffer();

            while ((inputLine = in.readLine()) != null) {
                responseBf.append(inputLine);
            }
            in.close();

            Logger.sysLog(LogValues.info, this.getClass().getName(),"["+msisdn+"] Response received = "+responseBf.toString());

            response = responseBf.toString();
            responseBf = null;
            if(inNodeDetails.getOperator().equalsIgnoreCase("digicel"))
            {
                if(response.startsWith("Received"))
                {
                    response = "ok";
                }
                else if(response.startsWith("{"))
                {
                    // {"id":"185688","status_billing":"INSUFFICIENT_FUNDS","status_sms":"FAILED"}
                    Logger.sysLog(LogValues.APP_DEBUG, this.getClass().getName(),"["+msisdn+"] Parsing json response.");
                    Gson gson = new Gson(); 
                    JsonResponse jsonResponse = gson.fromJson(response, JsonResponse.class);

                    if(jsonResponse.getStatus_billing().equalsIgnoreCase("ok") || jsonResponse.getStatus_billing().contains("SUCCESS")){
                        response="ok";
                    }
                    else if(jsonResponse.getStatus_billing().equalsIgnoreCase("INSUFFICIENT_FUNDS"))
                    {
                        Logger.sysLog(LogValues.APP_DEBUG, this.getClass().getName(),"["+msisdn+"] Response received for INSUFFICIENT_FUNDS.");
                        response = "low balance";
                    }
                    else if(jsonResponse.getStatus_billing().equalsIgnoreCase("FAILED"))
                    {
                        Logger.sysLog(LogValues.APP_DEBUG, this.getClass().getName(),"["+msisdn+"] Failure Response received for some other reason.");
                        response = "nok";
                    }           
                    else
                    {
                        if(inNodeDetails.getCountry().equalsIgnoreCase("JAM")||inNodeDetails.getCountry().equalsIgnoreCase("HAI")){
                            response=jsonResponse.getStatus_billing();
                        }
                        else{
                            gson = null;
                            jsonResponse = null;
                        }

                    }
                }
                else
                {
                    if(inNodeDetails.getCountry().equalsIgnoreCase("HAI") && response.contains("EXCEPTION"))
                    {
                        response = "ok";
                    }
                    else
                    {
                    Logger.sysLog(LogValues.APP_DEBUG, this.getClass().getName(),"["+msisdn+"] Unknown response.");
                    response = "nok";
                    }
                }
            }
        }
        else if(responseCode == 502 || responseCode == 500)
        {
            if(inNodeDetails.getCountry().equalsIgnoreCase("HAI") || inNodeDetails.getCountry().equalsIgnoreCase("JAM"))
            {
                response = "ok";
            }
            else
            {
                response = "nok";
            }

        }
        else
        {
            response = "nok";
            /*Map<String,List<String>> responseMap = con.getHeaderFields();
            for (Map.Entry entry : responseMap.entrySet()) {
                Logger.sysLog(LogValues.APP_DEBUG, Utility.class.getName(), "header key = "+entry.getKey() + " value = " + entry.getValue());
            }*/
        }

        return response;
    }
    catch(SocketTimeoutException ex)
    {
        Logger.sysLog(LogValues.APP_DEBUG, Utility.class.getName(), "Read Timeout occurs for msisdn = "+msisdn);
        return "ReadTimeout";
    }
    catch(ConnectTimeoutException ex1)
    {
        Logger.sysLog(LogValues.APP_DEBUG, Utility.class.getName(), "ConnectTimeoutException occurs for msisdn = "+msisdn);
        return "ConnectionTimeout";
    }
    catch(ConnectException ex2)
    {
        Logger.sysLog(LogValues.APP_DEBUG, Utility.class.getName(), "ConnectException occurs for msisdn = "+msisdn);
        return "ConnectionTimeout";
    }
    catch(JsonSyntaxException ex3){
        response=null;
        return response;
    }
    catch(MalformedJsonException ex4){
        response=null;
        return response;
    }
    catch(Exception e)
    {
        Logger.sysLog(LogValues.error, this.getClass().getName(),"["+msisdn+"] Internal Error occured"+coreException.GetStack(e));
        return response;
    }
    finally
    {
        response = null;
        url = null;
        obj = null;
        con.disconnect();
        Logger.sysLog(LogValues.APP_DEBUG, this.getClass().getName(),"Calling GC.");
        System.gc();
    }
    //return response;

}

但是，相同的代码在生产环境中运行得非常好，每秒大约有 50 个请求。

当我使用 JVisualVM 和 Sampler 时，我了解到这种方法“sendHttpGetReq”需要很长时间和高 CPU 处理。但从代码中，我找不到代码应该阻塞所有 CPU 的具体原因。

这是采样器屏幕截图：

请提出可能是什么问题？

Answer 1

我认为最终调用的 System.gc() 方法可能会导致问题。 建议您评论 System.gc() 并尝试一下。