2021 年 1 月，当时 Elastic 公司决定把 Elasticsearch 和 Kibana 的许可证从 Apache 2.0 变更为 Elastic License 2.0（ELv2）和 Server Side Public License（SSPL）双许可。尽管这两个许可证也允许源代码公开，但它们并不符合开源倡议组织（OSI）的开源定义。
应对质疑：“本就是一个错误，现在 Elastic 反悔了？”
“任何改变都会带来一些质疑，当然也会引来一些挑剔者。”在宣布 Elasticsearch 重新开源的同时，Shay Banon 就已经预料到会受到许多负面评论，为此他在博文中一一提前回应。
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“三年前更改许可证就是一个错误，所以现在 Elastic 反悔了”。
三年前我们更改许可证时，是为了缓解市场上的混乱局面。由于我们的决定，很多事情都改变了，但现在的环境完全不同了。我们不会活在过去，而是希望为用户构建一个更好的未来。正因为我们当时采取了行动，现在我们才有机会再次做出改变。
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“AGPL 不是完全的开源，XX 许可证才是。”
AGPL 是一个获得 OSI 认可的许可证，而且被广泛采用。例如，MongoDB 曾使用 AGPL，Grafana 现在也使用 AGPL。这表明 AGPL 并不会影响项目的使用或流行度。我们选择 AGPL 是因为我们相信，这是与 OSI 一起推动世界开源的最佳途径。
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“Elastic 现在才更改许可证，是因为这几年他们经营不佳。”
我想说的是，我对 Elastic 的未来依然充满期待，我也为我们的产品和团队执行力感到无比自豪。我们推出了无状态 Elasticsearch、ES|QL 以及大量针对生成式 AI 用例的向量数据库/混合搜索改进；我们在日志记录和可观察性方面大力采用 OTel；我们的安全信息和事件管理（SIEM）产品不断增加新功能，并且是市场上增长最快的产品之一……我可以向你保证，我们始终考虑的是长期发展，而这次的改变也是其中的一部分。
原文：Elasticsearch is Open Source, Again | Elastic Blog
Elasticsearch is Open Source, Again
作者
2024年8月30日
[D.N.A] Elasticsearch and Kibana can be called Open Source again. It is hard to express how happy this statement makes me. Literally jumping up and down with excitement here. All of us at Elastic are. Open source is in my DNA. It is in Elastic DNA. Being able to call Elasticsearch Open Source again is pure joy.
[LOVE.] The tl;dr is that we will be adding AGPL as another license option next to ELv2 and SSPL in the coming weeks. We never stopped believing and behaving like an open source community after we changed the license. But being able to use the term Open Source, by using AGPL, an OSI approved license, removes any questions, or fud, people might have.
[Not Like Us] We never stopped believing in Open Source at Elastic. I never stopped believing in Open Source. I’m going on 25 years and counting as a true believer. So why the change 3 years ago? We had issues with AWS and the market confusion their offering was causing. So after trying all the other options we could think of, we changed the license, knowing it would result in a fork of Elasticsearch with a different name and a different trajectory. It’s a long story.
[Like That] The good news is that while it was painful, it worked. 3 years later, Amazon is fully invested in their fork, the market confusion has been (mostly) resolved, and our partnership with AWS is stronger than ever. We were even named AWS partner of the year. I had always hoped that enough time would pass that we could feel safe to get back to being an Open Source project - and it finally has.
[All The Stars] We want to make the life of our users as simple as possible. We have people that really like ELv2 (a BSD inspired license). We have people that have SSPL approved (through MongoDB using it). Which is why we are simply adding another option, and not removing anything. If you already use and enjoy Elasticsearch, please carry on, nothing changed. For others, you now have the option to choose AGPL as well.
[LOYALTY.] We chose AGPL, vs another license, because we hope our work with OSI will help to have more options in the Open Source licensing world. And it seems like another OSI approved license will rhyme with SSPL and/or AGPL. Heck, maybe AGPL is enough for infrastructure software like us with how things have progressed since we had to change the license (for example, Grafana who moved to it from Apache2). We are committed to figure it out.
[euphoria] I am so happy to be able to call Elasticsearch Open Source again.
[Alright] With any change, there can be confusion, and, of course, there can be trolls. (Aren’t there always trolls?) Let’s have some fun and try to answer some of these.. Here are some I can imagine, but let’s keep adding to this.
- “Changing the license was a mistake, and Elastic now backtracks from it”. We removed a lot of market confusion when we changed our license 3 years ago. And because of our actions, a lot has changed. It’s an entirely different landscape now. We aren’t living in the past. We want to build a better future for our users. It’s because we took action then, that we are in a position to take action now.
- “AGPL is not true open source, license X is”: AGPL is an OSI approved license, and it's a widely adopted one. For example, MongoDB used to be AGPL and Grafana is AGPL. It shows that AGPL doesn’t affect usage or popularity. We chose AGPL because we believe it’s the best way to start to pave a path, with OSI, towards more Open Source in the world, not less.
- “Elastic changes the license because they are not doing well” - I will start by saying that I am as excited today as ever about the future of Elastic. I am tremendously proud of our products and our team's execution. We shipped Stateless Elasticsearch, ES|QL, and tons of vector database/hybrid search improvements for GenAI use cases. We are leaning heavily into OTel in logging and Observability. And our SIEM product in Security keeps adding amazing features and it's one of the fastest growing in the market. Users' response has been humbling. The stock market will have its ups and downs. What I can assure you, is that we are always thinking long term, and this change is part of it.
If we see more, we will add them above to hopefully reduce confusion.
[HUMBLE.] It’s so exciting to build for the future. Elasticsearch is back to being Open Source. Yay! What a wonderful thing to say. What a wonderful day.
Forever :elasticheart:
Open Source
Shay