我试图从单个mysql查询切换到mysql-pool连接，因此用户可以共享一个mysql连接，但我根本不熟悉这个（对于nodejs / socket也是新手） .IO）。
以下代码是我到目前为止每秒向数组中的套接字发送数据所做的：
var
port = process.env.OPENSHIFT_NODEJS_PORT || 8000,
ip = process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1',
app = require('http').createServer(handler),
fs = require('fs'),
request = require('request'),
mysql = require('mysql'),
moment = require('moment'),
tz = require('moment-timezone'),
pool = mysql.createPool({
connectionLimit: 100,
host: 'xxx',
user: 'xxx',
password: 'xxx',
database: 'xxx',
debug: false,
port: 3306}),
socketArray = [],
POLLING_INTERVAL = 1000,
pollingTimer;
moment.tz.setDefault("Europe/Berlin");
var io = require('socket.io').listen(app);
io.set('origins', '*:*');
function time()
{
output = new Date();
output = moment().format('(H:mm:ss.SS) ');
return output;
}
function handler(req,res)
{
res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
res.statusCode = 200;
res.connection.setTimeout(0);
res.end();
}
app.listen(port,ip);
function pollingLoop () {
if (socketArray.length === 0) {
// no connections, wait and try again
setTimeout(pollingLoop, POLLING_INTERVAL);
return; // continue without sending mysql query
}
pool.getConnection(function(err,connection){
if (err) { console.log({"code" : 100, "status" : "connection-db error"}); return; }
console.log('connected as id ' + connection.threadId);
console.log('socketArray length: ' + socketArray.length);
var selection =
"SELECT\
a.`id`,a.`product_id` AS pid,a.`random` AS nr,a.`price`,a.`price_end` AS pe,\
TIMESTAMPDIFF(SECOND,NOW(),a.`datetime`) AS duration,\
ABS(TIMESTAMPDIFF(SECOND,NOW(),b.`date`)) AS hb\
FROM `auctions` AS a\
LEFT JOIN `auctions_bids` AS b ON b.`auction_id` = a.`id`\
WHERE TIMESTAMPDIFF(SECOND,NOW(),a.`datetime`) > '-1'\
GROUP BY a.`id`\
ORDER BY `duration` DESC,`id` DESC LIMIT 15";
var streamArray = [], lg = '';
var query = connection.query(selection, function(err, results, rows){
lg += ('id: '+results[0].id+' ('+results[0].duration+') ');
if
(
((results[0].duration < 2 || results[0].duration <= results[0].nr) && (results[0].price <= results[0].pe))
||
((results[0].duration < 2 || results[0].duration <= results[0].nr) && (results[0].hb > 0 && results[0].hb < 30))
)
{
min = 3;
max = 5;
rand = Math.floor(Math.random()*(max-min+1)+min);
price = results[0].price+0.01;
price = price.toFixed(2);
pool.query('UPDATE `auctions` SET `random` = ?,`price` = ?, `datetime` = DATE_ADD(`datetime`,INTERVAL(17-TIMESTAMPDIFF(SECOND,NOW(),`datetime`))SECOND) WHERE `id` = ?',[rand, price, results[0].id]);
console.log(time()+'UPDATED id '+results[0].id+': random ('+rand+') price ('+price+'€)');
}
streamArray.push(results[0]);
updateSockets({ streamArray: streamArray });
console.log("auctions pushed: " + streamArray);
connection.release();
setTimeout(pollingLoop, POLLING_INTERVAL);
});
console.log(time()+lg+' C: '+socketArray.length);
});
}
pollingLoop();
io.sockets.on('connection', function(socket) {
socket.on('disconnect', function() {
clearTimeout(pollingTimer);
var socketIndex = socketArray.indexOf(socket);
console.log(time()+'SOCKET-ID = %s DISCONNECTED', socketIndex);
if (~socketIndex) { socketArray.splice(socketIndex, 1); }
});
console.log(time()+'NEW SOCKET CONNECTED!');
socketArray.push(socket);
});
var updateSockets = function(data) {
socketArray.forEach(function(tmpSocket) { tmpSocket.volatile.emit('stream', data); });
};
console.log(time()+'server.js executed\n');
但是这并没有向WebSocket发送任何数据。这种方法（代码结构）是否正确？以前我使用query.on('results')来获取这样的数据：
var selection = "SELECT * FROM auctions";
var query = mysql.query(selection), auctions = [];
query.on('result', function(auction) {
console.log('id: '+auction.id+' ('+auction.duration+') ');
});
这可以很好地显示auction.row的数据，但是如何在我的mysql池连接中执行此操作？
也过了几秒钟我收到release()甚至没有定义的错误，但它在mysql-module文档中列出了...所以我想我的整个逻辑过程在某种程度上是错误的。
setInterval(function () { mysql.query('SELECT
1'); }, 5000);作为答案
连接在这里活着？ （nodejs mysql Error: Connection lost The server closed the connection）（对我的一些问题感谢任何提示或答案！更好的答案比没有答案更好，因为我经历过这个话题没有得到很多回答。）
修改 更新了我的整个代码（见上文）。输出现在看起来像这样：http://s21.postimg.org/avsxa87rb/output.jpg
所以流获取数据，但是在console.log中什么都没有，并且出现了这个javascript错误？
答案 0 :(得分：0)
您应该创建一个池，并在该池上使用getConnection。然后，当您完成连接后，将其释放。此外，您不需要停止pollingLoop或为每个连接启动它，一个循环就足够了。
我没有理解带有条件的if语句，所以我省略了它。它可能需要去其他地方。
var socketArr = [];
function handler(req, res) {
res.statusCode = 200;
res.connection.setTimeout(0);
res.end();
}
app.listen(port, ip);
var pool = mysql.createPool({
host : 'example.org',
user : 'bob',
password : 'secret'
});
function pollingLoop () {
if (socketArr.length === 0) {
// no connections, wait and try again
setTimeout(pollingLoop, 1000);
return; // continue without sending mysql query
}
pool.getConnection(function (err, connection) {
if (err) {
console.log({
"code": 100,
"status": "Error in connection database"
});
return;
}
console.log('connected as id ' + connection.threadId);
var selection = "SELECT * FROM auctions";
var streamArray = [],
lg = '';
var query = connection.query(selection, function (err, results, fields, rows) {
lg += ('id: ' + results[0].id + ' (' + results[0].duration + ') ');
/*if (conditions) {
var query_update = connection.query('UPDATE `auctions` SET `price` = ? WHERE `id` = ?', [price, auction.id]);
console.log(time() + 'UPDATED id ' + auction.id + ': price (' + price + '€)');
}*/
streamArray.push(results);
updateSockets({
streamArray: streamArray
});
console.log("auctions pushed: " + streamArray);
connection.release();
setTimeout(pollingLoop, 1000);
});
console.log(time() + lg + ' C: ' + socketArr.length);
});
}
// start loop
pollingLoop();
io.sockets.on('connection', function (socket) {
socket.on('disconnect', function () {
var socketIndex = socketArr.indexOf(socket);
console.log(time() + 'SOCKET-ID = %s DISCONNECTED', socketIndex);
if (~socketIndex) {
socketArr.splice(socketIndex, 1);
}
});
console.log(time() + 'NEW SOCKET CONNECTED!');
socketArr.push(socket);
});
var updateSockets = function (data) {
socketArr.forEach(function (tmpSocket) {
tmpSocket.volatile.emit('stream', data);
});
};