In a recent post, I mentioned that we needed a MySQL clustering solution that scaled well with both reads and writes. I was fairly sure we handled more reads than writes. So I asked around: what percentage of our operations were reads? Nobody knew. Not content to leave the question unanswered, I spent 5 minutes figuring it out.
Do you know how to figure out what percentage of your MySQL operations are reads vs. writes?
It’s actually quite easy to do. One query and a calculator will tell you.
SHOW GLOBAL STATUS WHERE Variable_name IN ('Com_insert', 'Com_update', 'Com_select', 'Com_delete');
Here were our results:
| Command | Count |
|---|---|
| Com_delete | 102179 |
| Com_insert | 94037342 |
| Com_select | 372330876 |
| Com_update | 58800298 |
A little math will give you your read-to-write ratio. Ours is 71:29.
Take a minute to find your read-to-write ratio and post it in a comment. Let’s see what variation there is in this world.
Now write yourself a little script that takes these values (from time to time) and plots their differences. See how your ratio changes over time.
Alan on Development 