96 karma · joined February 24, 2022
1. We don't gzip layers like Docker does. Gzip is really slow, and it's much slower than the network. Storage is cheap. So it's much faster to transmit uncompressed layers than to transmit compressed layers and decompress them.
2. We've heavily tuned our agents for pulling layers fast. Disk throughput and IOPS are really important so we provision those higher than you typically would for running workloads in the cloud. When pulling layers we modify kernel parameters like the dirty_ratio to values that we've empirically found with layer pulls. We make sure we completely exhaust our network bandwidth and throughput when pulling layers. And so on.
3. This third one is experimental and something we're actively working on improving, but we have our own underlying filesystem which lazily loads the files from a layer instead of pulling tons of (potentially unneeded) files up front. This is similar to AWS's [Seekable OCI](https://github.com/awslabs/soci-snapshotter) but tuned for our particular needs.
I've been slowly working on improving our documentation to explain these kinds of differentiators that our architecture and container runtime provide, but most of it is unpublished so far. We definitely need to do a much better job of explaining _how_ we are faster and better rather than just stating it :).
The other side of this is that we also made _building_ those layers much much faster. We blogged a little bit about it at https://www.rwx.com/blog/we-deleted-our-dockerfiles but just to hit some quick notes: in RWX you can vary the compute by task, and it turns out throwing a big machine at (e.g.) `npm install` is quite effective. Plus we make using an incremental cache very easy, and layers generated from an incremental cache are only the incremental parts, so they tend to be smaller. And we're a DAG, so you can parallelize your setup in a way that is very painful to do with Docker, even when using multi-stage builds. And our cache registry is global and very hard to mess up, whereas a lot of people misconfigure their Docker caches and have cache misses all over their docker builds. And we have miss-then-hit semantics for caching. Okay, I'm rambling now! But happy to go into more depth on any of this!
Trying to justify the CVE before fully explaining the scope of the CVE, who is affected, or how to mitigate it -- yikes.
The author later asks what color class definitions were. I think this fundamentally gets wrong how syntax highlighting helps humans. I don't have a clue what color anything is in my favored highlighting, but my brain does incredible pattern recognition to help me digest code in it without me consciously knowing what color does what.
So his arguments for why there's a problem don't hold up, but that doesn't mean there is not in fact a problem.
[1] https://github.com/rwx-cloud/packages/blob/main/git/clone/bi...
[0] https://www.rwx.com/blog/retry-failures-while-run-in-progres...
> The orange remains in the living room. Moving the plate to the kitchen does not affect the location of the orange, since it was placed below the plate but not attached to it. Therefore, the orange stays where it was originally placed, which is in the living room.
You don't need to visualize it in your mind to understand the relationship between being _below_ and being _moved with_. Keep in mind that many people cannot visualize anything in their mind!