Acceleration Service has a garbage collector capable of removing resources
which are not used for a long time or unfrequently. The garbage collector consists
of leaseManager and leaseCache. The acceld has responsible for
ensuring that all resources(blobs) which are stored locally are held by
leases
at all times, else they will be cleared.
Acceleration Service uses leaseManager and leaseCache to manager all leases
which are persisted in boltdb. The leaseManager will creat a new lease for the
new blob and delete leases of the blobs which should be cleared away.
The leaseCache will sync with the leases which are persisted in boltdb and provide
the lease that should be cleared in LFRU(LFU first, LRU second) order. The acceld will
init leaseCache when daemon started.
Garbage Collection can be triggered in two ways. Firstly, gc will be triggered after each task completed. Secondly, gc has scheduled tasks every hourly since dameon started. GC clears the blobs until local storage size below 80% of the threshold. Specially, scheduled gc tasks clear the blobs until local storage size below 40% of the threshold.
| Configuration | Example | Description |
|---|---|---|
gcpolicy.threshold |
"100MB" | size threshold that triggers GC, the gc will start reclaim blobs if exceeds the size. |