[joncrocks]

The characterisation of JVM GC behavior seems slightly unfair.

Saying that JVMs are 'stop the world' and Pony is 'concurrent' feels like it's ignoring modern JVM GC strategies.

It might be true that you can avoid stop the world collection for an actor-system, but by logical extension would that not be possible on the JVM as well for that particular workload, given a suitably designed actor-system?

[spooneybarger]

Its possible yes. At the time we started working on Wallaroo, the only real option for concurrent GC on the JVM was Azul. And we didn't want to tie our product and our goals to another company's commercial offering.

My intent was not be unfair. There's a lot of nuance in the topic that can be hard to cover in a more general blog post. Garbage collection is a fascinating topic, there's a great amount of detail that is left out in that post. I was going to a broad overview of general thinking.

[edited for typo]

[exabrial]

I think this statement is a reach. There are plenty of concurrent collectors for the JVM, and there are tons of architectural and coding strategies to mitigate inconvenient GCs. This is not a one-of-a-kind problem, this is well studied and the path is well trodden. Azul is a convenient solution that wouldn't involve having to do a whole lot of case study, but it's certainly not the only one. And this is as-if perfect deterministic latency was the only factor that was important (then why not use C?).

What it sounds like instead was very minimal benchmarks or science was performed ahead of time, then a lot of justification written afterward. I know that's a reach as well, but this is a well-trodden path, so the answer "Pony is the best possible solution for the interest of our business" just seems like a very strange conclusion.

[riku_iki]

> At the time we started working on Wallaroo, the only real option for concurrent GC on the JVM was Azul.

Curious if you did any benchmarks for Pony against standard JVM Concurrent Mark Sweep GC, which aims to reduce GC induced pauses?

[spooneybarger]

It's not really an apples to apples comparison but before we went with Pony we did try out a number of things on the JVM.