mysql

Fixing MySQL SSL Replication Errors

I spent 2 nights trying to get mysql replication over ssl to work.. and kept hitting this generic error message: connection error 2026. After much searching and trying different things I finally found the solution that worked for me. If you are hitting this error here’s a short list of things to check.

What I do: Practical Data Visualization

I’m often ask what it is I do for a living… and being lazy I usually just say ‘computer stuff’.   In an effort to provide a little more context to anyone who may be interested this is one in a series of postings where I’ll cover some aspect of what it is I do.

In my current role I spend part of the time doing development projects. (aka programming) I’m not a hard core developer though.. it’s not my full time occupation nor do I want it to be.  I work mostly with perl and php when necessary, mysql and occasionally PostgreSQL or Oracle all under various flavors of linux. (debian is my favorite). Usually these development tasks are related to some sort of management automation for a global VoIP network but sometimes they involve making complex things easier to understand.  Part of that involves automating the collection of large amounts of data and then presenting in a meaningful way so that problems and long term trends can be identified.  What follows are some examples of the sorts of things I mean.

What I do: Power DNS Real World Results

We have had a Power DNS recursing cacher deployed at one of our busiest sites for a few months now and I thought others might benefit from some real world performance info.  This is running on some older hardware.. dual Xenon 2.8Ghz system with 4G of ram and the only job it’s doing is running this recursor. These three graphs tell the tale.  The first shows that the system is handling peaks of about 3800 queries per second and that about 99% of those are being answered in a fraction of a millisecond.  The second shows that cache hits are averaging about 70-75% and the third shows that it’s doing this work while using at most one quarter of the CPU.  Add to those impressive performance levels that I’ve had zero issues since putting it in production six months ago.

What I do: Mysql Reporting Date Range Cheat Sheet

If you have to do any sort of reporting using mysql or other databases you will probably need to use relative date ranges that don’t depend on what day the report is being run. That is if you need a report for ‘last month’ that runs from the first to last day of the previous month.. or previous 3 months etc but not include any days in the current month.   Here is a small collection of queries…