Today’s work was a mix of routine tasks and unexpected challenges. I started by checking the server logs for any errors or anomalies. The logs are often like a detective novel—full of clues that tell a story, if you know how to read them.

I opened up /var/log/apache2/error.log on one of our Apache servers and found several 500 Internal Server Error messages. Usually, this means something is misconfigured in the virtual hosts file or perhaps there’s an issue with PHP scripts. After a quick grep for error messages, I narrowed it down to a specific line: PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/extensions/no-debug-non-zts-20060613/mysql.so' - /usr/lib/php/extensions/no-debug-non-zts-20060613/mysql.so: cannot open shared object file: No such file or directory in Unknown on line 0.

I remembered installing a new version of MySQL, and the PHP extension might not have been updated to match. I needed to update the php.ini file to point to the correct path for the MySQL extension. It was a small fix, but it reminded me of how critical it is to keep dependencies in sync.

After fixing that issue, I moved on to another machine where I found a user complaining about slow performance. Running top revealed that one process, an old cron job running a Python script, was consuming 10% CPU. The script was supposed to send out newsletter emails every hour, but it had grown in complexity over time and was now inefficient.

I decided to refactor the code using some of the new-fangled Python tools I’ve been wanting to try out—multiprocessing, specifically. I wrote a quick script to parallelize the email sending process so that each recipient would get their email almost simultaneously, rather than one at a time. After running pylint to catch any obvious bugs and ensuring everything was good, I pushed it up and watched as the CPU usage dropped back to normal levels.

Around lunchtime, there was an unexpected issue with our database replication. The primary server was reporting lag, but the secondary wasn’t catching up. I checked the mysql.show_process_list command and found a bunch of long-running queries that seemed to be blocking the replication process. I decided to kill some of these queries to get things moving again. After a bit of trial and error, I managed to bring the lag down significantly.

During a brief break from my work station, I heard the team arguing about whether we should switch to Xen for our virtualization needs instead of KVM. They were weighing the pros and cons, but everyone agreed that LXC seemed promising as well. It was clear they wanted to move away from VMs for more lightweight containers.

In the afternoon, there was a bit of downtime where I could catch up on some reading and learnings. I came across a blog post about using Docker for development environments, which looked interesting. The idea of having consistent, reproducible environments seemed like it would save us a lot of headache in the future.

As the day wound down, I found myself reflecting on how much technology has changed over just a few years. Back then, we were still using mostly Bash scripts and Perl for automation, but now Python was becoming ubiquitous in our stack. The rise of open-source tools like Docker and LXC felt like a natural progression from what we had been doing.

Tomorrow’s plan is to set up some automated testing for the refactored email script and get started with Docker containers for development. It feels good to have these new technologies to work with, but I’m also excited about tackling more of our legacy scripts and improving them.

That’s it for today. Back to normal sysadmin life, one error message at a time.