Google Unveils Elastic Caching, Cutting Spanner I/O Costs to 0.5% as Memory Runs Up to $3 per GiB
Updated
Updated · Google Research · Jun 25
Google Unveils Elastic Caching, Cutting Spanner I/O Costs to 0.5% as Memory Runs Up to $3 per GiB
2 articles · Updated · Google Research · Jun 25
Summary
Google Cloud and Google Research said their new linear elastic caching system dynamically changes cache size and reduced total cache ownership costs in Spanner tests while keeping added I/O costs to just 0.5%.
The approach treats page eviction as a ski-rental problem, assigning each page a time-to-live with a lightweight decision-tree model and falling back to LRU only when the cache physically fills.
Google said the method targets a cloud economics problem in which fixed-size caches are either too small for performance or overprovisioned for peak demand, with some serverless providers charging up to $3 a day for 1 GiB of memory.
Public-trace evaluations also showed elastic caching consistently beat fixed-size baselines, with savings growing as memory costs rise relative to cache-miss costs.
Presented at CIDR 2025 and now described as part of Spanner production deployments, the work points to more granular, pay-as-you-go infrastructure using cost-aware caching instead of static peak provisioning.