Railgun reaches end of support in January

Cloudflare has announced it will deprecate Railgun on January 31, 2024. After that date, existing Railgun deployments and connections will stop working. Customers have eight months to migrate to supported alternatives, with the recommended replacement varying by use case.

Railgun launched over a decade ago as a delta compression solution for dynamically generated content that could not be cached at Cloudflare's edge. The product worked by running a listener inside the customer's environment that established a persistent TCP connection to a sender service in Cloudflare's network. When a request arrived for a known page, the listener fetched the page from the origin, determined what had changed since the last request, and sent only that difference to the sender.

The product's last major release was in 2015. Cloudflare said it kept Railgun in maintenance mode rather than formally ending it, but that approach caused the product to stagnate: feature requests went unaddressed, and maintenance work consumed resources that could have improved newer replacements. According to the company, a product should be retired when its maintenance impedes work on new problems and when better alternatives exist for customers to adopt.

Why now

Cloudflare's network has changed substantially since Railgun was last updated. The company now operates in more than 285 cities, nearly triple the number when Railgun was current. The software platform has also evolved: every data center runs every service Cloudflare offers, from reverse proxy products to Workers compute and storage. Supporting that range of services requires a platform that can adapt to evolving product needs.

Maintaining Railgun within that platform creates a burden on continued investment in new solutions. Some underlying tools that power Railgun are approaching end of life, while others present security risks Cloudflare is not comfortable accepting.

Cloudflare considered three options before settling on deprecation:

  • Accept the consequences of inaction, leaving the network in a worse state and customers stranded on a stagnant product.
  • Run Railgun on dedicated, siloed infrastructure, which would violate the principle that every piece of hardware runs every service.
  • Stand up a new engineering team to rebuild Railgun from scratch in a modern way.

The company rejected all three. A rebuild in particular would divert resources from newer technologies and duplicate features already available in other products. Railgun will instead be shut down, and customers are being directed to existing Cloudflare services that address the same problems.

Alternative paths by use case

There is no direct like-for-like successor to Railgun. The problems it solved have since been addressed by different products, and the appropriate migration path depends on why a customer deployed Railgun in the first place.

Persistent, secure connections without a public IP: Cloudflare Tunnel runs software in the customer environment, similar to the Railgun listener, and creates an outbound-only connection to Cloudflare's network. It does not require exposing a public IP address and is available at no cost.

Fronting multiple services: Cloudflare Tunnel can be deployed in bastion mode to support multiple services running behind it. It can handle non-HTTP services, and connector replicas can be deployed for high availability.

Performance improvements: Cloudflare points to two services that address the acceleration Railgun provided:

  • Cloudflare Tunnel includes Argo Smart Routing, which optimizes both the middle mile and last mile, reducing round trip time by up to 40%. Web assets using Argo perform on average 30% faster overall.
  • Cloudflare Network Interconnect (CNI) provides a dedicated physical or virtual connection to Cloudflare's network for improved reliability and performance between Cloudflare and customer infrastructure.

Reducing origin egress: For customers concerned about data transfer costs, Cloudflare recommends two options:

  • The Bandwidth Alliance, whose members mutually waive transfer fees. Oracle Cloud, Microsoft Azure, Google Cloud, Backblaze and more than a dozen other providers charge zero cost to send data to Cloudflare.
  • R2, Cloudflare's object storage product, which has zero egress fees, an S3-compatible API, and easy migration for building multi-cloud architectures.

Migration timeline and support

January 31, 2024 is the last day Railgun connections will be supported. As of February 1, 2024, existing connections will stop functioning. New Railgun deployments will be blocked within the next few days, but zones with established Railgun connections will continue to work during the migration window.

Contract customers can work with their Customer Success team on migration plans. Cloudflare said each region has a specialist available to help teams that need additional guidance. Customers can also ask questions in a dedicated forum thread, which Cloudflare staff will monitor and respond to.

Customers will receive repeated email notices over the eight-month migration window, starting later today with the initial announcement.