Valkey: A Redis Fork With a Future

SEATTLE — The free license that Redis offers under its new license is not a great deal, says the lead contributor to the Valkey project, the new Redis fork backed by The Linux Foundation.

“So a lot of people just look at the fact that the new license that Redis is putting out is free for end users,” said Madelyn Olson, a former core contributor to the Redis project, in an interview for The New Stack Makers. The episode, which included Valkey maintainers from Google and Oracle, was recorded at the Open Source Summit in April.

“But what they’re really not seeing is that all of the contributors that currently worked on Redis often won’t work with that new license,” Olson said.

The key to any open source project is the people behind it. So far, Valkey has emerged fast as a fork with a future. It has 13,000 stars, 43 contributors, and technologists leading the project from major cloud services. A contributor summit is in the works.

‘Continuity Is Really the Top Priority’

Valkey, an in-memory data store, emerged after Redis, the company, moved the code base to a more restrictive license. “Beginning with version 7.2.4, Redis will be dual-licensed under the Redis Source Available License (RSALv2) and Server Side Public License (SSPLv1),” wrote Joab Jackson in The New Stack. “Older versions will remain open source.”

Now a Valkey maintainer, Olson works at Amazon Web Services (AWS). Her work reflects the new project’s importance for the world’s largest tech companies, as evident in Google and Oracle’s roles as maintainers on Valkey. Joining Olson for our conversation were Ping Xie, a Google staff software engineer, and Dmitry Polyakovsky, a consulting member of Oracle’s technical staff.

“A lot of the big companies are looking for free open source permissive licenses to work with and contribute to,” Olson said. “So the end user will really just see less contributions to the product that they’re currently using. And they’ll see slower bug fixes, slower momentum overall.”

Now the work turns to continuity, modules such as one for Rust, and the core engine itself to keep performance strong.

“Continuity is really the top priority, we want to make sure there’s a smooth path for everyone who is currently on Redis 7.2.5,” Xie said.

Valkey will use a more incremental patch version, Olson said. The next major release will come by the end of the year. The goal is one major version per year, with a three-year maintenance cycle.

Modules and the Client Ecosystem

Valkey will emphasize modules to extend its overall functionality. Valkey has a rich ecosystem of various libraries, but you have to work in C. Developing modules in Rust could help attract more engineers.

“Redis itself has been supporting modules for about six years,”  Polyakovsky said. “There have been some modules built and, ironically, some of them were licensed differently. So you couldn’t use them as easily as a Redis itself. But I think there can be very interesting new features built into Valkey, but they might not belong in the core Valkey. So they can be built as modules.”

There’s always discussion of using new technologies that complement Valkey.

“So what about building a vector similarity search module?”  Polyakovsky asked. “What about building a module to do maybe secondary indexes, all kinds of things you can do with Redis or Valkey, with the right module, but keeping the core functionality the same? So that keeps that continuity that gives us compatibility. And the people who choose to use additional new features that would install modules and they would then use those modules only for what they need.”

Continuity comes in many forms.

“For instance, there are many different types of implementation on the client side,” Xie said. “And then they do things differently. So those differences in the behavior sometimes confuse the customer. So being able to help the client ecosystem to consolidate on those behaviors will be a big plus for everybody.”

Check out the full episode for more on the maintainers’ plans for Valkey.