Live data from Hacker News

Mount Mayhem at Netflix: Scaling Containers on Modern CPUs

netflixtechblog.com

1–10 of 35 posts

Re: Mount Mayhem at Netflix: Scaling Containers on Modern CPUs

#5

- can someone kindly explain why there are 2 websites that all claim to be netflix tech blog? - website 1 https://netflixtechblog.medium.com/ - website 2 https://netflixtechblog.com/

I mean Netflix is dealing with big, important things like container scaling, creating a million micro services talking to each other and so on. Having multiple tech blogging platform on Medium is not something they have a spare moment to think about.

Re: Mount Mayhem at Netflix: Scaling Containers on Modern CPUs

#8
I am not familiar with the nitty gritty of container instance building process, so maybe I'm just not the intended audience, but this is particularly unclear to me:

  > To avoid the costly process of untarring and shifting UIDs for every container, the new runtime uses the kernel’s idmap feature. This allows efficient UID mapping per container without copying or changing file ownership, which is why containerd performs many mounts
Why does using idmap require to perform more mount?

Re: Mount Mayhem at Netflix: Scaling Containers on Modern CPUs

#9
Okay, I'll ask the dumb question: Couldn't you also reduce the number of layers per container? Sure, if you can reuse layers you should, but unless you've done something very clever like 1 package per layer I struggle to think that 50 is really useful?

Re: Mount Mayhem at Netflix: Scaling Containers on Modern CPUs

#10

Okay, I'll ask the dumb question: Couldn't you also reduce the number of layers per container? Sure, if you can reuse layers you should, but unless you've done something very clever like 1 package per layer I struggle to think that 50 is really useful?

> unless you've done something very clever like 1 package per layer I struggle to think that 50 is really useful?

1 package per layer can actually be quite nice, since it means that any package updates will only affect that layer, meaning that downloading container updates will use much less network bandwidth. This is nice for things like bootc [0] that are deployed on the "edge", but less useful for things deployed in a well-connected server farm.

[0]: https://bootc-dev.github.io/bootc/

Post reply on HN