For consistency with other systems, the redis and caching monitoring data has
been moved under the "registry" section in expvar. This ensures the entire
registry state is kept to a single section.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
This changeset integrates the layer info cache with the registry webapp and
storage backend. The main benefit is to cache immutable layer meta data,
reducing backend roundtrips. The cache can be configured to use either redis or
an inmemory cache.
This provides massive performance benefits for HEAD http checks on layer blobs
and manifest verification.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
