Redis Is Open Source Again

Redis, the popular in-memory data store, is open source again.

After a year of dual-sourcing its code under the proprietary Redis Source Available License v2 (RSALv2) and the Server Side Public License v1 (SSPLv1), Redis 8 is now available under the decidedly (open source) AGPL v3 license.

This move comes after AWS, Google, Oracle and others backed the Valkey fork, which got quite a bit of traction in the open source community over the last few months.

The reason Redis moved to this licensing scheme a year ago was to keep some of the major cloud providers from offering Redis as a hosted service on their platforms. Under the new license, they would have to license Redis, which Microsoft did.

“We had to shake Amazon, Google off our back — and Microsoft to some degree,” Redis CEO Rowan Trollope told me during an interview earlier this month. “I spent some time talking to the CEO of Elasticsearch, and it’s exactly the same thing that they went through. It’s really just a repeat of that. When I talked to him, I was: ‘Why did you do that?’ And he was: ‘We had them just copying the code, and we couldn’t put anything into Elastic without [them doing that] — and the main thing was to protect the brand.’“

But changing the license was only what Trollope called “medium successful.” When I talked to him last year, he expected that Amazon and others would launch a fork, which is exactly what happened with Valkey.

“Over the fullness of time, these will no longer be the same product,” Trollope said. “Right now, it’s effectively a year old. We’re launching Redis 8. So the divergence point really starts now.”

Trollope noted that he had hoped that the Open Source Initiative — which is essentially the gatekeeper for which license is considered “open source” — would maybe reconsider its position on the SSPL. That didn’t happen.

“So we got Microsoft on Redis, but that allowed Amazon and Google to essentially craft a narrative, which was: Valkey is the open source alternative to Redis,” Trollope said.

When I asked Trollope a year ago about how the original change away from open source to the new license would likely be perceived by its customers, he argued that the vast majority didn’t care. Now, however, he admits that some of this was confirmation bias.

“Our customers didn’t care, but the people who weren’t our customers, some of them did care — and we weren’t talking to them,” he said. “So, my mistake. As I went out and talked to more potential customers, they started to raise this: ‘We like the idea of open source.’ And no matter how much I said that the SSPL is essentially the same as open source, it was like pushing string uphill. And I was: ‘This isn’t working. Like, oh shit, what do we do now?’”

When Redis co-founder Salvatore Sanfilippo returned to the company last year, he and Trollope started talking about moving Redis back under an open source license now that the move to a proprietary license had achieved what the company had set out to do.

“We really thought it through and said, ‘Actually, this makes sense.’ Because Amazon and Google have made their bed, we could adopt the AGPL license. So that’s the license for Redis 8 and we believe that the AGPL license provides protection from the [cloud service providers] in that, if they want to offer us as an open source version, which they can do, they have to publish all the code as open source. They have internal policies that say they won’t do that. So we think it’s an effective model.”

Originally, Redis didn’t want to use the AGPL, Trollope said. That’s because even though the team believed that Amazon was unlikely to go along with the license’s stipulations, Redis’ lawyers argued that since Amazon’s Redis business is worth billions of dollars (or at least that’s what Trollope argues), that could make Amazon change its stance on the AGPL.

Trollope also admitted that he and the rest of the company didn’t fully engage with the open source community. Sanfilippo may now have the credibility in the community to do that, he believes, but at the time, the company remained mostly silent, “and that was a mistake,” Trollope said.

Redis does not believe that the Valkey fork has made much of a dent in the overall Redis community.

“We have 98% of the people that actually contributed to Redis open source work for Redis. The people that are on the foundation of Valkey really were more of the fringe contributors, with the one exception of Madelyn [Olson], who is a good contributor,” Trollope said — and immediately walked that back. “That sounds more pejorative than I needed to be. We respect those people. We love that they’re doing that. We would like them to be contributors on Redis again.”

As for Redis 8 itself, it’ll come with include the new vector sets, which Sanfilippo created during his time back at Redis, as well as a number of performance improvements. What’s maybe even more important, though, is that it will also integrate all of the packages from Redis Stack, which was previously available under a separate license but is now reintegrated into the overall Redis distribution again. This brings features like JSON, Time Series and probabilistic data support to Redis.