Google Cloud SQL or node-mysql answers a long time - google-cloud-sql

Question

We have this project using Polymer as the FrontEnd and Node.js as the API being consumed by Polymer, and our Node API replies a really long time especially if you just leave the page alone for like 10 minutes. Upon further investigation by inserting a DATE calculation in the MySQL Query, I found out that MySQL responds a Really long time. The query looks like this:
var query = dataStruct['formed_query'];
console.log(query);
var now = Date.now();
console.log("Getting Data for Foobar Query============ "+Date());
console.log(query);
GLOBAL.db_foobar.getConnection(function(err1, connection) {
////console.log("requesting MySQL connection");
if(err1==null)
{
connection.query(query,function(err,rows,fields){
console.log("response from MySQL Foobar Query============= "+Date());
console.log("MySQL response Foobar Query=========> "+(Date.now()-now)+" ms");
if(err==null)
{
//respond.respondJSON is just a res.json(msg); but I've added a similar calculation for response time starting from express router.route until res.json occurs
respond.respondJSON(dataJSON['resVal'],res,req);
}else{
var msg = {
"status":"Error",
"desc":"[Foobar Query]Error Getting Connection",
"err":err1,
"db_name":"common",
"query":query
};
respond.respondError(msg,res,req);
}
connection.release();
});
}else{
var msg = {
"status":"Error",
"desc":"[Foobar Query]Error Getting Connection",
"err":err1,
"db_name":"common",
"query":query
};
respond.respondJSON(msg,res,req);
respond.emailError(msg);
try{
connection.release();
}catch(err_release){
respond.LogInConsole(err_release);
respond.LogInConsole(err_release.stack);
}
}
});
}
When Chrome Developer tools reports a LONG PENDING time for the API, this happens to my log.
SELECT * FROM `foobar_table` LIMIT 0,20;
MySQL response Foobar Query=========> 10006 ms
I'm dumbfounded as to why this is happening.
We have our system hosted in Google Cloud Services. Our MySQL is a Google SQL service with an activation policy of ALWAYS. We've also set that our Node Server, which is a Google Compute Engine, to keep alive TCP4 connections via:
echo 'net.ipv4.tcp_keepalive_time = 60' | sudo tee -a /etc/sysctl.conf
sudo /sbin/sysctl --load=/etc/sysctl.conf
I'm using mysql Pool from node-mysql
db_init.database = 'foobar_dbname';
db_init=ssl_set(db_init);
//GLOBAL.db_foobar = mysql.createConnection(db_init);
GLOBAL.db_foobar = mysql.createPool(db_init);
GLOBAL.db_foobar.on('connection', function (connection) {
setTimeout(tryForceRelease, mysqlForceTimeOut,connection);
});
db_init looks like this:
db_init = {
host : 'ip_address_of_GCS_SQL',
user : 'user_name_of_GCS_SQL[![enter image description here][1]][1]',
password : '',
database : '',
supportBigNumbers: true,
connectionLimit:100
};
I'm also forcing to release connections if they're not released in 2 minutes, just to make sure it's released
function tryForceRelease(connection)
{
try{
//console.log("force releasing connection");
connection.release();
}catch(err){
//do nothing
//console.log("connection already released");
}
}
This is really wracking my brains out here. If anyone can help please do.

Answer 1

I'll post the same answer here as I posted in node-mysql pool experiences ETIMEDOUT.
The questions are sufficiently different that I'm not sure it's worth duping them.
I suspect the reason is that keepalive is not enabled on the connection to the MySQL server.
node-mysql does not have an option to enable keepalive and neither does node-mysql2, but node-mysql2 provides a way to supply a custom function for creating sockets which we can use to enable keepalive:
var mysql = require('mysql2');
var net = require('net');
var pool = mysql.createPool({
connectionLimit : 100,
host : '123.123.123.123',
user : 'foo',
password : 'bar',
database : 'baz',
stream : function(opts) {
var socket = net.connect(opts.config.port, opts.config.host);
socket.setKeepAlive(true);
return socket;
}
});