获得“未能开始接受连接”将我的应用程序部署到蓝色时

Question

hi am facing facing" from face"在将我的应用推向蓝色时，无法开始接受连接"错误"错误。是否可以帮助我。...我的代码片段如下：

var express     = require('express');
app         = express();
var ibmbluemix  = require('ibmbluemix') 
var ibmdb = require('ibm_db');
var http = require('http');
var url = require('url');
var logger = ibmbluemix.getLogger();
var PORT = (process.env.VCAP_APP_PORT || 8000);
var HOST = (process.env.VCAP_APP_HOST || 'localhost');
var queryData = null;
var serviceName = 'SQLDB';
if (process.env.VCAP_SERVICES) {
   var env = JSON.parse(process.env.VCAP_SERVICES);
   db2 = env['sqldb'][0].credentials;
}
else{
   console.error("INFORMATION FOR DB CONNECTION NOT FOUND");
}
var dbConnection = "DRIVER={DB2};DATABASE=" + db2.db + ";UID=" +  db2.username + ";PWD=" + db2.password + ";HOSTNAME=" + db2.hostname +  ";port=" + db2.port;
console.log("Connection String: " + dbConnection);
http.createServer(function(request, response) {
    console.log('Creating the http server');
    ibmdb.open(dbConnection, function(err, conn) {
        if (err) {
            response.send("error occurred " + err.message);
        }
        else {
            console.log('before select');
            conn.query("SELECT FULL_NAME,  PASSWORD,  SHORT_ID FROM USER02130.USER_DETAILS", function(err,  rows, moreResultSets) {
                console.log('Connection result error '+err);
                console.log('no of records is '+rows.length);
                response.writeHead(200, { 'Content-Type': 'application/json'});
                response.write(JSON.stringify(rows));
                response.end();
            });
        }
}).listen(PORT, HOST);

任何人都可以帮我吗，谢谢

Answer 1

您的摘要中有一些句法错误（缺少关闭括号等）。尝试使用此方法：

var express     = require('express');
app = express();
var ibmbluemix  = require('ibmbluemix') 
var ibmdb = require('ibm_db');
var http = require('http');
var url = require('url');
var logger = ibmbluemix.getLogger();
var PORT = (process.env.VCAP_APP_PORT || 8000);
var HOST = (process.env.VCAP_APP_HOST || 'localhost');
var queryData = null;
var serviceName = 'SQLDB';
if (process.env.VCAP_SERVICES) {
   var env = JSON.parse(process.env.VCAP_SERVICES);
   var db2 = env['sqldb'][0].credentials; // missed declaration
}
else{
    console.error("INFORMATION FOR DB CONNECTION NOT FOUND");
}
var dbConnection = "DRIVER={DB2};DATABASE=" + db2.db + ";UID=" +  db2.username + ";PWD=" + db2.password + ";HOSTNAME=" + db2.hostname +  ";port=" + db2.port;
console.log("Connection String: " + dbConnection);
http.createServer(function(request, response) {
    console.log('server request'); // does not create a server on every request
    ibmdb.open(dbConnection, function(err, conn) {
        if (err) {
            response.send("error occurred " + err.message);
        }
        else {
            console.log('before select');
            conn.query("SELECT FULL_NAME,  PASSWORD,  SHORT_ID FROM USER02130.USER_DETAILS", function(err,  rows, moreResultSets) {
                console.log('Connection result error '+err);
                console.log('no of records is '+rows.length);
                response.writeHead(200, { 'Content-Type': 'application/json'});
                response.write(JSON.stringify(rows));
                response.end();
            });
        }
    }) // missed closing brackets
}).listen(PORT, HOST);
console.log("Server running at "+HOST+" on port "+ PORT);

node.js很容易在本地设置，请在此处获取。本地运行它可以帮助您确定许多问题，例如句法错误。

希望它有帮助！

Answer 2

cf logs <app name> --recent

此命令将为您提供日志，该日志将显示您的语法错误所在。

Answer 3

很高兴您弄清楚它，但是对于将来的参考，"未能开始接受连接"错误通常意味着该代码在之前的初始化期间抛出了例外调用http.createServer(...).listen(port, host)。在调用listen(...)

之前，尝试在下面添加代码

process.on('uncaughtException', function (err) {
    console.log(err);
}); 

如果启动代码出于不可预见的原因而不是接收默认的"应用程序崩溃"消息，则您的控制台日志将包括有用的堆栈跟踪。

仍然卡住了吗？Pat Mueller在Node.js调试中提供了其他有用的建议，从更好的记录开始！和David Clements的Node.js提示＃1：开发调试技术提供了更多高级调试技巧，例如功能De-Anonymization。