Replace large-chunk blob downloads with parallel small-chunk
verification to solve timeout and performance issues. Registry users
experienced progressively slowing download speeds as large-chunk
transfers aged, often timing out completely.
The previous approach downloaded blobs in a few large chunks but
required a separate, single-threaded pass to read the entire blob back
from disk for verification after download completion.
This change uses the new chunksums API to fetch many smaller
chunk+digest pairs, allowing concurrent downloads and immediate
verification as each chunk arrives. Chunks are written directly to their
final positions, eliminating the entire separate verification pass.
The result is more reliable downloads that maintain speed throughout the
transfer process and significantly faster overall completion, especially
over unstable connections or with large blobs.
This commit replaces the old pull implementation in the server package
with the new, faster, more robust pull implementation in the registry
package.
The new endpoint, and now the remove endpoint too, are behind the
feature gate "client2" enabled only by setting the OLLAMA_EXPERIMENT
environment variable include "client2".
Currently, the progress indication is wired to perform the same as the
previous implementation to avoid making changes to the CLI, and because
the status reports happen at the start of the download, and the end of
the write to disk, the progress indication is not as smooth as it could
be. This is a known issue and will be addressed in a future change.
This implementation may be ~0.5-1.0% slower in rare cases, depending on
network and disk speed, but is generally MUCH faster and more robust
than the its predecessor in all other cases.
Previously, using a Registry required a DiskCache to be passed in for
use in various methods. This was a bit cumbersome, as the DiskCache is
required for most operations, and the DefaultCache is used in most of
those cases. This change makes the DiskCache an optional field on the
Registry struct.
This also changes DefaultCache to initialize on first use. This is to
not burden clients with the cost of creating a new cache per use, or
having to hold onto a cache for the lifetime of the Registry.
Also, slip in some minor docs updates for Trace.
This commit is a step towards a goal to make names less ceremonial
outside of the registry client. Clients of the registry package can
treat names as opaque strings, and the registry package will handle
parsing, validating, and normalizing names.
Ideally we end up with the names package tucked away in an internal
package for good. We'll see how things go.
Also, this package name is not permanent. This another step in the
on-going process of refactoring the server code, and at some point it
will most likely be renamed/moved.
This commit introduces a new API implementation for handling
interactions with the registry and the local model cache. The new API is
located in server/internal/registry. The package name is "registry" and
should be considered temporary; it is hidden and not bleeding outside of
the server package. As the commits roll in, we'll start consuming more
of the API and then let reverse osmosis take effect, at which point it
will surface closer to the root level packages as much as needed.
