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> "BONUS: Capsule OSv" That could be something decent. I'd be interested to know what performance benefits you get from using Capsule to manage OSv. Does anyon

> "BONUS: Capsule OSv" That could be something decent. I'd be interested to know what performance benefits you get from using Capsule to manage OSv. Does anyone have a JVM-based Docker app they could use for comparison?

mike_hearn 11y ago
The performance boost for using OSv can be pretty significant if you can use it (it's a rather specialised tool). You're effectively using the hypervisor as a kernel. If you mean "a docker based app on OSv" then the answer is almost certainly no, as OSv is an operating system that's designed to only run one or two apps at once. It's not a regular operating system at all. I don't think Docker would likely even start on it.
- pron 11y ago
  Right, but luckily JVM applications do run on OSv, and they have even made some modifications to HotSpot that can use more efficient (non-POSIX) syscalls for added performance (esp. networking I believe).
- mwcampbell 11y ago
  I think it would be more interesting to compare a JVm app running on OSV inside a VM to the same JVM app running in a Docker-compatible container on bare metal. In both cases you effectively have a single process running on a kernel, without the extra kernel in between (as in the common case of an app running on a general-purpose OS in a VM). But virtualization probably still has extra overhead. And of course, the hypervisor offers lower-level abstractions to the VM than a general-purpose kernel would offer to a container; for example, for storage, you get a block device rather than a filesystem. Note that I said Docker-compatible. One alternative to the Docker Engine itself would be Joyent's Triton, which uses Illumos rather than Linux as the kernel (while still supporting Linux binaries), so it doesn't have the security problems of Linux namespaces + cgroups.
- ZenoArrow 11y ago
  Sorry, I wasn't clear, I mean comparing a JVM app managed in a Docker container with a JVM app running on OSv managed by capsule.

mike_hearn 11y ago

The performance boost for using OSv can be pretty significant if you can use it (it's a rather specialised tool). You're effectively using the hypervisor as a kernel. If you mean "a docker based app on OSv" then the answer is almost certainly no, as OSv is an operating system that's designed to only run one or two apps at once. It's not a regular operating system at all. I don't think Docker would likely even start on it.

pron 11y ago
Right, but luckily JVM applications do run on OSv, and they have even made some modifications to HotSpot that can use more efficient (non-POSIX) syscalls for added performance (esp. networking I believe).
mwcampbell 11y ago
I think it would be more interesting to compare a JVm app running on OSV inside a VM to the same JVM app running in a Docker-compatible container on bare metal. In both cases you effectively have a single process running on a kernel, without the extra kernel in between (as in the common case of an app running on a general-purpose OS in a VM). But virtualization probably still has extra overhead. And of course, the hypervisor offers lower-level abstractions to the VM than a general-purpose kernel would offer to a container; for example, for storage, you get a block device rather than a filesystem. Note that I said Docker-compatible. One alternative to the Docker Engine itself would be Joyent's Triton, which uses Illumos rather than Linux as the kernel (while still supporting Linux binaries), so it doesn't have the security problems of Linux namespaces + cgroups.
ZenoArrow 11y ago
Sorry, I wasn't clear, I mean comparing a JVM app managed in a Docker container with a JVM app running on OSv managed by capsule.