To allow better control the cache eviction process.
Introduce MINIO_CACHE_WATERMARK_LOW and
MINIO_CACHE_WATERMARK_HIGH env. variables to specify
when to stop/start cache eviction process.
Deprecate MINIO_CACHE_EXPIRY environment variable. Cache
gc sweeps at 30 minute intervals whenever high watermark is
reached to clear least recently accessed entries in the cache
until sufficient space is cleared to reach the low watermark.
Garbage collection uses an adaptive file scoring approach based
on last access time, with greater weights assigned to larger
objects and those with more hits to find the candidates for eviction.
Thanks to @klauspost for this file scoring algorithm
Co-authored-by: Klaus Post <klauspost@minio.io>
X-Cache sets cache status of HIT if object is
served from the disk cache, or MISS otherwise.
X-Cache-Lookup is set to HIT if object was found
in the cache even if not served (for e.g. if cache
entry was invalidated by ETag verification)
Fixes#7458Fixes#7573Fixes#7938Fixes#6934Fixes#6265Fixes#6630
This will allow the cache to consistently work for
server and gateways. Range GET requests will
be cached in the background after the request
is served from the backend.
- All cached content is automatically bitrot protected.
- Avoid ETag verification if a cache-control header
is set and the cached content is still valid.
- This PR changes the cache backend format, and all existing
content will be migrated to the new format. Until the data is
migrated completely, all content will be served from the backend.
This will allow cache to consistently work for
server and gateways. Range GET requests will
be cached in the background after the request
is served from the backend.
Fixes: #7458, #7573, #6265, #6630
poornas