I have 2 Virtual Machines on Azure in the same Virtual Network.
One virtual machine runs a NodeJs process which is responsible for MySQL operations.
Other virtual machine runs a MySQL instance. I can connect to it from the other VM and from the NodeJs process fine.
Sometimes it will fail and throw an error about Connection timeout when acquiring a connection from the pool.
My connection string uses a local IP address from within the Virtual Network to access the database so it should have this much delay to exceed a 10 second timeout. When it works it's rapid, I mean really fast! But sometimes it just breaks and randomly starts working again. Anyone ever come across this?
If it's any help this is a MySQL instance based on Ubuntu Server 15.10.
Exception:
{
"error": {
"name": "Error",
"status": 500,
"message": "connect ETIMEDOUT",
"errorno": "ETIMEDOUT",
"code": "ETIMEDOUT",
"syscall": "connect",
"fatal": true,
"stack": "Error: connect ETIMEDOUT
at PoolConnection.Connection._handleConnectTimeout (projectdir/node_modules/loopback-connector-mysql/node_modules/mysql/lib/Connection.js:375:13)
at Socket.g (events.js:180:16)
at Socket.EventEmitter.emit (events.js:92:17)
at Socket._onTimeout (net.js:327:8)
at Timer.unrefTimeout [as ontimeout] (timers.js:412:13)
--------------------
at Protocol._enqueue (projectdir/node_modules/loopback-connector-mysql/node_modules/mysql/lib/protocol/Protocol.js:135:48)
at Protocol.handshake (projectdir/node_modules/loopback-connector-mysql/node_modules/mysql/lib/protocol/Protocol.js:52:41)
at PoolConnection.connect (projectdir/node_modules/loopback-connector-mysql/node_modules/mysql/lib/Connection.js:123:18)
at Pool.getConnection (projectdir/node_modules/loopback-connector-mysql/node_modules/mysql/lib/Pool.js:45:23)
at MySQL.executeSQL (projectdir/node_modules/loopback-connector-mysql/lib/mysql.js:200:12)
at projectdir/node_modules/loopback-connector-mysql/node_modules/loopback-connector/lib/sql.js:408:10
at projectdir/node_modules/loopback-datasource-juggler/lib/observer.js:175:9
at doNotify (projectdir/node_modules/loopback-datasource-juggler/lib/observer.js:93:49)
at MySQL.ObserverMixin._notifyBaseObservers (projectdir/node_modules/loopback-datasource-juggler/lib/observer.js:116:5)
at MySQL.ObserverMixin.notifyObserversOf (projectdir/node_modules/loopback-datasource-juggler/lib/observer.js:91:8)"
}
}