Alright, so today I’m gonna walk you through my experience messing around with Havran. I’ve been hearing a lot about it, so I figured, why not give it a shot?
First things first, I went straight to the Havran GitHub repo. Started by cloning the thing down to my local machine. Nothing too fancy there, just a simple git clone.
Then, I dove into the docs. Gotta at least pretend I know what I’m doing, right? Read through the basic concepts, figured out the main idea behind it – distributed lock management. Seemed pretty straightforward.
Next up, I needed a test environment. Didn’t want to mess with anything important. I spun up a couple of Docker containers with ZooKeeper. Havran needs ZooKeeper to do its magic, so that was step one.
After getting ZooKeeper up and running, I started writing some test code. Just a simple Java program to acquire and release locks. I used the Havran client library, of course. Had to add the dependency to my Maven project. That part was pretty easy.
Here’s where things got a little tricky. The first time I ran the code, I kept getting connection errors. Turns out I had the ZooKeeper connection string wrong. Spent a good hour debugging that. Eventually, I figured it out – stupid typo.
Once the connection was sorted, I could actually acquire and release locks. I wrote some more code to simulate concurrent access. Multiple threads trying to grab the same lock at the same time. It was cool to see Havran actually working, preventing race conditions and all that jazz.
Then, I started playing around with different lock configurations. Havran lets you set timeouts, retries, and other parameters. I wanted to see how it behaved under different conditions. Like, what happens if a ZooKeeper node goes down? Or if a lock holder crashes? Good stuff to test.
I even tried simulating network partitions. Killed a few Docker containers to isolate parts of the ZooKeeper cluster. Havran handled it pretty gracefully, all things considered. The locks eventually timed out, and the other clients were able to acquire them.
Overall, it was a pretty interesting experience. Havran seems like a solid piece of technology. It’s not exactly rocket science, but it does the job well. I can definitely see myself using it in a real-world project, especially if I need reliable distributed locks.
The biggest takeaway for me was the importance of proper configuration. Getting the ZooKeeper connection string right is crucial, obviously. But also, understanding the different lock parameters and how they affect behavior is key.
Anyway, that’s my Havran adventure. Hope it was helpful. Now, back to coding!
