We have relatively modest AWS bills w/ Lensley, but it’s been inching upwards and broke $400/mo at the beginning of the year. Originally, I thought this was mostly just due to ever increasing S3 usage, but it turns out that wasn’t the case. After going through and trimming things, we’ll end up saving about $250/mo, which isn’t a huge absolute amount ($3K/yr) but was over 60% of our monthly.

• Obviously there were a couple EC2 instances hanging around that we didn’t need. One was a bit pernicious since it kept regenerating (not a Spot Request, but actually due to an old Elastic Beanstalk test. Oops.)
• Our Reserved Instances had lapsed, so everything was 50% more than it should have been. Double oops.
• Our instances were running old and busted m1’s – with our usage I was able to switch m1.smalls to t2.micros and m1.medium to t2.smalls, cutting costs by 2/3’s (w/ equal Reserved discounts).
• Note: T2s are HVM only. Migrating from PV to HVM wasn’t too bad, although I also took the opportunity to switch one machine to the new 16.04 LTS (if you don’t have to, don’t – besides some package migrations, there’s also a killer kswapd bug that pegs the CPU)
• It’s worth noting here that one of the instances was running EBS Magnetic storage. Obviously worth snapshotting and switching over to gp2.
• We’ve been paying for an ELB and MultiAZ instances but honestly, have never had to use the failover. At the risk of jinxing myself having typed that, I just got rid of them.
• A few years ago I switched to a Multi-AZ RDS instance for our database. At the time this seemed like a good idea, and while I never had to worry about things, w/ the rollout of gp2 (SSD) EBS w/ plenty of IOPs, it seemed maybe a bit wasteful for minimal convenience. Switching from Multi-AZ db.m1.medium to a t2.medium w/ a 100GB gp2 EBS volume lowers our monthly cost from ~$160/mo to $33/mo
• Clearing out unused EBS volumes/snapshots, ofc

A big chunk of our savings were the result of getting rid of some redundancy, but since I can count the number of single-AZ outages (we’re in us-west-2 in Oregon) we’ve been affected by over the past 3 or 4 years on a single hand and there’s nothing super-mission critical that can’t live with a few minutes of downtime.