Cloudflare freed up 100TB of RAM behind its 1.1.1.1 DNS without adding a single server

Cloudflare has successfully freed up 100TB of memory associated with its 1.1.1.1 DNS service. This achievement was reached without the addition of any new servers to the company's infrastructure. The process involved a redesign of the DNS cache, specifically focusing on trimming cache entries by tens of bytes at a time. According to the Cloudflare Blog, this optimization focused on the efficiency of how memory is allocated and stored for the massive volume of DNS requests the service handles globally. Coverage of this technical overhaul has been reported by a variety of outlets including GIGAZINE, TechSpot, XenoSpectrum, and Yahoo Tech, as well as igor´sLAB and finance.biggo.com.

These reports emphasize that the memory savings were achieved by shrinking the size of individual cache entries. Yahoo Tech highlights the scale of the operation, noting that because there are 250 billion cached DNS entries present at any given time, the waste of a single byte per entry results in a total loss of 250GB of RAM across the fleet. The context for this move lies in the immense scale of the 1.1.1.1 DNS service. Because the system manages billions of entries simultaneously, minor inefficiencies in data storage are magnified across the entire server fleet. By overhauling the cache design to remove unnecessary bytes, Cloudflare was able to reclaim a significant amount of hardware resources.

This illustrates the impact that micro-optimizations can have when applied to global-scale infrastructure where small changes per entry scale into terabytes of saved memory. Future attention will likely remain on how Cloudflare continues to optimize its DNS cache and whether similar redesigns are applied to other parts of its network. Based on the reports from TechSpot and the Cloudflare Blog, the current focus has been on the specific memory footprint of the 1.1.1.1 service. Coverage does not yet specify if these optimization techniques will be expanded to other services beyond the DNS cache or if further memory reductions are targeted for the coming months.