Saving £1m on Cloud Compute via cost optimisation
As a household brand and a High Street staple, this customer is a leader in its retail space. Growing significantly over the last few years with the trend of healthier living driving its new-found popularity.
If growth wasn’t placing enough stress on ageing IT systems, aggressive business goals rendered the IT solutions in situ no longer fit for purpose.
Public Cloud was a natural choice – instantly accessible, consumption based Operational Expenditure, and a modern, agile IT platform that would bode well for the future. The adoption strategy was for a replica build of the existing on premises footprint to be implemented and the architecture to evolve once operational.
Following replica builds from non-Cloud platforms, ‘waste’ or over-provisioning began to appear very quickly. The customer had not only re-introduced years of IT ‘sprawl’ but had added more capacity, getting these systems ‘right-sized’ was now critical.
Our aim was to reduce spend immediately by carrying out cost analysis and identifying opportunities for cost optimisation. We used Trusted Advisor and Cost Explorer in AWS to easily identify quick wins. Looking at deployed resources and ensuring we have some decent tagging and segmenting the data based on usage and nature of the resource.
Next we can identified the actions to take based on the data:
- Retire resources that are no longer required or have no (traceable) owners
- Right-size — remove unnecessary waste from resources with too much capacity; ensure the resource type matches the workload requirements
- Reserve — Reserved Instances can bring large savings. Once right-sized and it’s established that resources have a longer-term need, reserve them
- Spot Instances — where possible look to use on-demand instances. ‘Spot’ are specific to workload types but offer huge savings
- Savings plans — commit to a certain expenditure on compute resources to save large amounts of expenditure
There were quick wins and take-aways to investigate or validate further. What was clear, of the 170 EC2 instances, 90% were under-utilised. 50% of the total was less than 5% utilised at historic and measurable peak. 20% of the total were effectively idle and unused for months. Of the 350TB of storage, 19GB had been allocated to HDD with the rest all utilising SSD. All 350TB being directly attached EBS volumes, with only 200GB found in S3. 150TB of SSD storage holding snapshots dating back a year, despite policy requiring no more than a calendar month. Another 50TB was without an owner and subsequently found to be a copy of an obsolete on-premises back-up. Tagging was partial, so tracking owners to verify requirements was more difficult but not impossible.
A Reservation strategy did not exist, but the logic behind the process stated above was not difficult to embed.
Applying a simple process, alongside knowledge and experience has identified huge savings for a number of customers. After a week of analyses, easy to implement quick-wins totalled more than £1 million in annual savings for one High Street customer.