In cloud architecture, we often prioritize performance, scale, and security, but they can come with surprising costs. In one of our Azure-based deployments, our team discovered that a seemingly simple caching solution—designed only to support basic key-value storage—was costing us more than $5,000 per month.
At the heart of this cost was our use of Azure Cache for Redis (Premium), which we had adopted to meet Virtual Network (VNet) isolation requirements across a multi-region, multi-environment setup (production, development, staging, etc.). Each region and environment required its own Redis instance to comply with security and infrastructure separation standards. Although our caching needs were minimal—less than 200 MB of data that refreshed only once per hour—we had no choice but to use Redis Premium for VNet support.
Why Redis Premium wasn’t the right fit
Originally, we used Azure Redis Standard, which was cost-effective and suitable for our use case. However, we soon faced a compliance requirement: All services needed to be isolated via VNet integration. Redis Standard, unfortunately, does not support VNets. The only option was to move to the Premium tier, which starts at a significantly higher price point.