Update distribution roadmap.

Update pull through cache status.
Add section for metadata storage.

Signed-off-by: Richard Scothern <richard.scothern@gmail.com>
This commit is contained in:
Richard Scothern 2015-10-27 17:20:49 -07:00
parent 1c5f8166e4
commit 183d144520

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@ -103,20 +103,20 @@ via IRC or the mailing list and we can talk about adding it. The goal here is
to make sure that new features go through a rigid design process before
landing in the registry.
##### Mirroring and Pull-through Caching
##### Proxying to other Registries
Mirroring and pull-through caching are related but slight different. We've
adopted the term _mirroring_ to be a proper mirror of a registry, meaning it
has all the content the upstream would have. Providing such mirrors in the
Docker ecosystem is dependent on a solid trust system, which is still in the
works.
A _pull-through caching_ mode exists for the registry, but is restricted from
within the docker client to only mirror the official Docker Hub. This functionality
can be expanded when image provenance has been specified and implemented in the
distribution project.
The more commonly helpful feature is _pull-through caching_, where data is
fetched from an upstream when not available in a local registry instance.
##### Metadata storage
Please see the following issues:
- https://github.com/docker/distribution/issues/459
Metadata for the registry is currently stored with the manifest and layer data on
the storage backend. While this is a big win for simplicity and reliably maintaining
state, it comes with the cost of consistency and high latency. The mutable registry
metadata operations should be abstracted behind an API which will allow ACID compliant
storage systems to handle metadata.
##### Peer to Peer transfer