Using mext to format saved mysqladmin output nicely

I wrote a while ago about how mext works – it runs “mysqladmin extended-status” and formats it nicely. But what if you want to use it to format saved output that you’ve put into a file? It’s actually very easy. You can tell it what command-line to run to generate its input. By default you are probably going to tell it to run “mysqladmin ext -ri10″ or something like that, but you can just as easily make it run “cat my-saved-output”.

Let’s see how this can be useful. Imagine I have a server that stalls every now and then, and I’ve set up mk-loadavg to watch for this and capture information about system activity with a script that contains

$ mysqladmin ext -c 30 -i1 > mysqladmin-output.txt

That’ll gather 30 samples one second apart. Now I’ll format it:

$ wget -q
$ sh mext -r -- cat mysqladmin-output.txt | less -S

I’m piping the output into less -S so that I can see unwrapped output. 30 samples of mysql status variables are going to be aligned in columns next to each other, so without the -S flag I’ll probably see something unhelpful.

If you have a hard time visualizing the above, go ahead and run the commands! It’ll take only a minute, and it’ll make a lot more sense to you then. This is a really useful way to summarize and understand what is going on (or has gone on) inside your MySQL server.

About The Author

Baron is the founder and CEO of VividCortex. He is the author of High Performance MySQL and many open-source tools for performance analysis, monitoring, and system administration. Baron contributes to various database communities such as Oracle, PostgreSQL, Redis and MongoDB.