Well, landlord is unknown to me, but it has all caps "EXPERIMENTAL" and had[1] 3 people working on it, so I wouldn't use it in production.
GraalVM is interesting, and it has isolates and from my memory it has plenty of sandboxing features like limiting network and file system access. However, it has some big downsides: it's Oracle, people still associate it with your regular JVM and all its downsides. Yeah, it can match v8 in performance if you let it warm up (it takes longer for it to warm up compared to V8.) and it's even further from what CF does in terms of compatibility with existing ecosystem.
CloudFlare workers have single digit cold-start time[2]. GraalVM is...200ms and that is considered blazing fast by JVM standards. Takes longer and slower at runtime and probably more memory consumed.
Remember, we're not talking about long-running services, we're talking about short-lived request handlers in JavaScript that run on edge. Pricing for workers is per request. It's in CF interests to serve customers requests as fast as possible. Also remember that customers want to write JavaScript.
Why is Oracle an issue? GraalVM is under GPLv2 which does not cover patents. Some performance and security features locked in Enterprise version. In addition, first production-ready version was in 2019, CF already launched workers by then.
[1]: Last commit 2018. I doubt this is a feature complete software...
GraalVM is interesting, and it has isolates and from my memory it has plenty of sandboxing features like limiting network and file system access. However, it has some big downsides: it's Oracle, people still associate it with your regular JVM and all its downsides. Yeah, it can match v8 in performance if you let it warm up (it takes longer for it to warm up compared to V8.) and it's even further from what CF does in terms of compatibility with existing ecosystem.
CloudFlare workers have single digit cold-start time[2]. GraalVM is...200ms and that is considered blazing fast by JVM standards. Takes longer and slower at runtime and probably more memory consumed.
Remember, we're not talking about long-running services, we're talking about short-lived request handlers in JavaScript that run on edge. Pricing for workers is per request. It's in CF interests to serve customers requests as fast as possible. Also remember that customers want to write JavaScript.
Why is Oracle an issue? GraalVM is under GPLv2 which does not cover patents. Some performance and security features locked in Enterprise version. In addition, first production-ready version was in 2019, CF already launched workers by then.
[1]: Last commit 2018. I doubt this is a feature complete software...
[2]: https://blog.cloudflare.com/eliminating-cold-starts-with-clo...