Carrol C just joined IniTech. They were hiring for someone who could help them tame their cloud costs. There’s a lot of money being spent on AWS. Management had bought in on the “it’s cheaper than on-prem”, and were starting to wonder why that promise wasn’t being fulfilled.

After a little settling in period, Carrol had his credentials for their AWS environment, and started digging around just to familiarize himself with the infrastructure. This environment had started as an on-prem system that got migrated to the cloud, so the infrastructure was mostly a collection of virtual-machines using attached virtual disks- EBS- for storing data.

And that was the first red flag. Each VM was using between 160–200GB of EBS. CPU usage was hovering at around 15%, and RAM was barely a blip, but the quantity of disk was getting a more than a little out of hand. Carrol scribbled a few notes on a post-it, and went down the hall to visit Merna’s cube. Merna was one of the engineers responsible for developing the application. “Hey, Merna, question for you: how big is our application code and deployable artifacts?”

“Oh, depends on which instance you’re talking about, but the biggest weighs in at about a gig,” Merna said. “But we have some additional stuff installed on our VM image, so the VM image itself is about 4GB.”

“And what does-” Carrol paused to check his note- “the WRPT–073 instance do?”

“Oh, that’s just a simple webserver. Just generates some reports. Barely operates at capacity on even a Micro instance.”

“So… why is the disk sized for 200GB?”

Merna looked at Carrol like he had just asked the dumbest possible question. “Logs, obviously,” she said.

“… you have 196ish gigs of logs?”

Merna nodded. “We might need them.”

“AWS has a log aggregator that doesn’t store the logs on EBS. You could just ship them there and use logrotate to trim your logs, and that would be way cheaper.”

Merna shook her head. “You say that, but- oh, hold on.” Merna’s email bleeped at her: instance WRPT–073 was getting close to its disk capacity threshold. She quickly pulled up the AWS console and added another 10GB to the disk, before turning back to Carrol. “A lot of those accessory services have highly variable costs, and it makes it hard to predict your spend. Using cloud VMs is a much more consistent option. But if you feel so strongly about it, you could submit a request and we’ll evaluate it for a future release.”

Carrol submitted a request, and also pinged his new boss. “I think I know a way we can manage costs.” For now, Merna and the other engineers just expand disks when they fill up. It remains to be seen if anything actually changes, but regardless, Carrol is prepared for an “interesting” time at IniTech.