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DB reconnect when connection lost occurred #57
Description
Is it possible to catch and handle 'connection lost' event and try to reconnect to db now?
I use mysql driver and I have wait_timeout set in mysql config, so, if connection is inactive for some time, mysql closes it and node-mysql throws an error.
I tryed to catch it with db.driver.on or db.driver.db.on, but no success.
So, I have two questions:
- What should I do in this situation? Should I just ping db every n seconds, or there is another solution?
- What is happening when I do
db.driver.db.on? As far as I understand, db.driver.on is an instance of node-mysql connection. But, when I do:
var mysql = require('mysql');
var conn = mysql.createConnection(my_params);
conn.connect(my_cb);
conn.on('error', function (e) { ... }); // I'm doing this in node REPL, so error handler is attached after db is connected.everything works well, and, when I do:
var orm = require('orm');
orm.connect(my_params, function (e, db) {
db.driver.db.on('error', function (e) { ... }); //There can be db.driver.on also
});node-mysql just throws unhandled exception and the whole process ends.
Any help would be appreciated!
Activity
dresende commentedon Mar 4, 2013
db.driveris an ORM Driver abstraction, that defines a couple of common methods. Every native driver (mysql, postgres) has one ORM Driver to make the methods behave the same way.Pinging the database is in my opinion the best solution, I have to export it so people don't need to go deep in the ORM object to do it. Dropping the connection and reconnecting takes time and resources (client goes offline, free mem, client comes online again, alloc mem, ..). I think pinging and having the connection idle improves startup time (on requests) and has almost no impact in the database (assuming you have only 1 connection per app and not 1 per request).
Adds db.ping() (#57)
unikoid commentedon Mar 5, 2013
Thank you for your reply. I have understood your point, so I'll continue to use db.ping().
Also, there's a typo in my first post, I really meant 'As far as I understand, db.driver.db is an instance of node-mysql connection.' So, isn't it?