mysqladmin and MySQL Administrator issues with MySQL Proxy using rw-splitting.lua?
I am currently evaluating MySQL Proxy for a new project, and what I've seen so far is wonderful, but I have a few questions. For my evaluation I am running four virtual machines under VMWare Workstation 5.5.1, one with MySQL Proxy 0.60.0 built from source running under Gentoo Linux, and three with Win32 and MySQL 5.1.22, one master replicating to two slaves.
At first I ran MySQL Proxy on another Win32 session (we're a Windows shop), but it gave me several strange errors, including the "can't change DB to on slave" error others have reported here. I received it with mysqladmin and MySQL Administrator, but not when I just used the command-line mysql client and connected. I was dismayed, so I decided to sleep on the problem.
Today I noted that the developer mentioned that 0.61.0 wasn't released yet because of Win32 problems, I figured I'd try it out under Linux, which I did. The same problems are evident, so I looked at rw-splitting.lua. I ended up changing line 277 from "c.default_db and c.default_db ~= s.default_db then" to "#c.default_db > 0 and c.default_db ~= s.default_db then" and now everything works fine. Is this an acceptable change with no side effects? (I am a developer, but never coded in Lua before.)
Second, if I wanted to do reads against my master on queries as well as the two slaves, I had to define a --proxy-read-only-backend-addresses entry for the master. Is that normal, and will it cause any problems if I do so?
Lastly, what's the general limit on returned datasets that MySQL Proxy handles? Is it just limited by available memory? Is there a way to flush the data from the MySQL server to the client without caching it first apart from a small temporary buffer if that's the case, to remove such a limitation?
Thanks for your help!