我在PCF上有一个连接到mariadb实例的nodejs应用程序。实例wait_timeout是600，因此在不活动后它会在10分钟后断开连接。
在运行此应用程序并连接到docker上的本地mariadb实例的本地计算机上（一旦超时命中或我终止连接），我将得到一个MySQL Server has gone away然后我的应用程序将重新连接并给我数据库结果。它不会在本地崩溃。
在PCF上运行时，mariadb错误会使应用程序崩溃，或者如果异常被捕获，它将崩溃并发送一个Headers already sent error
我相信一旦MariaDB以某种方式杀死了连接，即使我在连接上有事件处理程序，节点中的mariadb驱动程序也不会被通知连接已终止。因此，一旦我的应用程序尝试运行查询，它就会失败，因为事件未被触发并且它试图在已关闭的连接上运行它。
我的连接模块
// Loading local .env vars
var route_helper = require("./route_helper");
route_helper.loadLocalEnvVars();
var Client = require('mariasql');
var moment = require('moment');
var connection = null;
try{
connection = new Client({
host: process.env.DB_MARIA_HOST,
user: process.env.DB_MARIA_USER,
password: process.env.DB_MARIA_PASS,
db: process.env.DB_MARIA_SCHEMA,
port: parseInt(process.env.DB_MARIA_PORT),
connTimeout: 20,
pingInterval: 1,
compress: true
});
connection.connect(function(err){
if(!err) {
if(process.env.DEBUG == "true"){
console.log("Database is connected");
}
} else {
console.log("Error connecting database " + err.message);
console.log(err);
}
});
connection.on('ready',function(){
if(process.env.DEBUG == "true"){
console.log("Connection ready " + moment().format('MMMM Do YYYY, h:mm:ss a') )
}
});
connection.on('close',function(){
if(process.env.DEBUG == "true"){
console.log("Connection closed " + moment().format('MMMM Do YYYY, h:mm:ss a') )
}
});
connection.on('error',function(err){
if(process.env.DEBUG == "true"){
console.log("Connection timeout... Reconnecting")
console.log(err);
}
if(err.code == 2006 ){
this.connect();
}
//this.connect();
});
}catch(err){
console.log("Maria_db error")
console.log(err)
throw err;
}
module.exports = connection;
加载Server路由器
var routes = require("./routes/application.js").appRouter(server);
var server = server.listen(process.env.PORT, function () {
console.log("Listening on port %s...", server.address().port);
});
我的路线
app.get("/applications", function (req, res) {
try{
var applications;
var dbConn = require("../util/db.js");
dbConn.query('SELECT some stuff’, function (error, results) {
if(!error) {
applications = {
"apps": results
}
return res.send(applications);
} else {
return res.send({"status": "error", "message": error.code});
}
});
}catch(err) {
console.log(err)
}
});
MySql已经消失了
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] OUT { Error: MySQL server has gone away
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] OUT at /home/vcap/app/node_modules/mariasql/lib/Client.js:223:12
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at Client.<anonymous> (/home/vcap/app/util/dbHealth.js:14:9)
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at emitOne (events.js:101:20)
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at Client.emit (events.js:191:7)
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at Client._onerror (/home/vcap/app/node_modules/mariasql/lib/Client.js:395:10)
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at Client._processQueue (/home/vcap/app/node_modules/mariasql/lib/Client.js:614:18)
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at /home/vcap/app/node_modules/mariasql/lib/Client.js:223:12
2017-12-20T09:03:55.29-0500 [APP/PROC/WEB/0] ERR at process._tickCallback (internal/process/next_tick.js:104:9)
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! Exit status 1
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! Failed at the [email protected] start script 'node server.js'.
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! not with npm itself.
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! You can get information on how to open an issue for this project with:
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! npm bugs myapplication
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! Or if that isn't available, you can get their info via:
2017-12-20T09:03:55.31-0500 [APP/PROC/WEB/0] ERR npm ERR! npm owner ls myapplication
2017-12-20T09:03:55.33-0500 [APP/PROC/WEB/0] ERR npm ERR! Please include the following file with any support request:
2017-12-20T09:03:55.33-0500 [APP/PROC/WEB/0] ERR npm ERR! /home/vcap/app/.npm/_logs/2017-12-20T14_03_55_316Z-debug.log
标题已发送错误。它们似乎也是乱序的，这很奇怪。在此测试期间，我向3个不同的服务发送3个http请求并收到此错误。
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at _combinedTickCallback (internal/process/next_tick.js:131:7)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at Client._processQueue (/home/vcap/app/node_modules/mariasql/lib/Client.js:614:18)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at process._tickCallback (internal/process/next_tick.js:180:9) code: 2006 }
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR _http_outgoing.js:494
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at validateHeader (_http_outgoing.js:494:11)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at ServerResponse.send (/home/vcap/app/node_modules/express/lib/response.js:158:21)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at Object.cb (/home/vcap/app/routes/application.js:474:29)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at Client._processQueue (/home/vcap/app/node_modules/mariasql/lib/Client.js:614:18)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at _combinedTickCallback (internal/process/next_tick.js:131:7)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at process._tickCallback (internal/process/next_tick.js:180:9) code: 2006 }
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR throw new Error('Can\'t set headers after they are sent.');
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR Error: Can't set headers after they are sent.
2017-12-27T11:07:46.41-0500 [APP/PROC/WEB/0] OUT Connection timeout... Reconnecting
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at /home/vcap/app/node_modules/mariasql/lib/Client.js:223:12
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT { Error: MySQL server has gone away
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT { Error: MySQL server has gone away
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at _combinedTickCallback (internal/process/next_tick.js:131:7)
2017-12-27T11:07:46.41-0500 [APP/PROC/WEB/0] OUT Route: /applications
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT { Error: MySQL server has gone away
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at Client._processQueue (/home/vcap/app/node_modules/mariasql/lib/Client.js:614:18)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at /home/vcap/app/node_modules/mariasql/lib/Client.js:223:12
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at ServerResponse.setHeader (_http_outgoing.js:501:3)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at ServerResponse.header (/home/vcap/app/node_modules/express/lib/response.js:767:10)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at process._tickCallback (internal/process/next_tick.js:180:9) code: 2006 }
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] OUT at /home/vcap/app/node_modules/mariasql/lib/Client.js:223:12
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR ^
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at ServerResponse.send (/home/vcap/app/node_modules/express/lib/response.js:170:12)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at ServerResponse.json (/home/vcap/app/node_modules/express/lib/response.js:267:15)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at cleanupReqs (/home/vcap/app/node_modules/mariasql/lib/Client.js:744:11)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at Client._onclose (/home/vcap/app/node_modules/mariasql/lib/Client.js:574:5)
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR at Client._onerror (/home/vcap/app/node_modules/mariasql/lib/Client.js:396:10)
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! Failed at the [email protected] start script.
2017-12-27T11:07:46.42-0500 [APP/PROC/WEB/0] ERR npm ERR! code ELIFECYCLE
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR!
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! [email protected] start: `node server.js`
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! Exit status 1
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! errno 1
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! A complete log of this run can be found in:
2017-12-27T11:07:46.43-0500 [APP/PROC/WEB/0] ERR npm ERR! /home/vcap/app/.npm/_logs/2017-12-27T16_07_46_432Z-debug.log
编辑：此应用程序结构由swagger生成
我只从mariasql npm驱动程序切换到knex驱动程序。即使knex依赖有mariasql: '^0.2.3'它开箱即用，没有任何问题。