Comments on Jonathan Levin's Axioms: SSH Tunneling between databases with MySQL

Creating an ssh-tunnel for MySQL replication is so...

2008-12-04T21:11:00.000Z

Creating an ssh-tunnel for MySQL replication is something I believe that people should do when replicating over WANs (internet or intranet, PVCs, Leased lines etc).

Why? The answer is actually quite simple. TCP has a simple 16bit CRC for each packet: Errors on private circuits tend to be bursty and are rarely single-bit errors ... The more data that is transferred, the greater the chance that there would be an undetected data error which would break replication and other bad foo.

Wrapping the replication connection inside an SSH tunnel insures against that possibility by effectively having a 128bit check.

I use this method as well. In fact, SSH is the onl...

2008-12-04T15:50:00.000Z

I use this method as well. In fact, SSH is the only protocol over which I send data or read data from my servers. If I do a remote backup - it's over SSH tunneling. If I want to login as root - my MySQL installation is configured to only allow root logins from localhost - I use tunneling.

Shlomi

I do this all the time on my vmware instance to co...

2008-12-04T14:40:00.000Z

I do this all the time on my vmware instance to connect to databases on our production environment.
A good "how to" about SSH tunnels can be found here: http://www.revsys.com/writings/quicktips/ssh-tunnel.html

e.g.
ssh -f user@remotehost -L 3306:127.0.0.1:3306 -N

then just connect to 127.0.0.1:3306 on the machine where you opened the tunnel and voila