Honestly, I don't really understand why G1 is being pushed so hard.
The parallel collector is a perfectly fine collector, particularly for smaller heaps. Even the serial collector isn't bad for things like a containerized environment, yet G1 replaces it by default now [1].
It's not a bad algorithm, but especially when you start talking about sub 2G environments I've not seen a situation where the parallel and serial collectors won't handily beat G1 on pretty much every metric. Major collectors with modern CPUs just doesn't take much time for a lot of memory.
The parallel collector is a perfectly fine collector, particularly for smaller heaps. Even the serial collector isn't bad for things like a containerized environment, yet G1 replaces it by default now [1].
It's not a bad algorithm, but especially when you start talking about sub 2G environments I've not seen a situation where the parallel and serial collectors won't handily beat G1 on pretty much every metric. Major collectors with modern CPUs just doesn't take much time for a lot of memory.
[1] https://openjdk.org/jeps/523