most of the delete calls today spend time in
a blocking operation where multiple calls need
to be recursively sent to delete the objects,
instead we can use rename operation to atomically
move the objects from the namespace to `tmp/.trash`
we can schedule deletion of objects at this
location once in 15, 30mins and we can also add
wait times between each delete operation.
this allows us to make delete's faster as well
less chattier on the drives, each server runs locally
a groutine which would clean this up regularly.
store the cache in-memory instead of disks to avoid large
write amplifications for list heavy workloads, store in
memory instead and let it auto expire.
currently crawler waits for an entire readdir call to
return until it processes usage, lifecycle, replication
and healing - instead we should pass the applicator all
the way down to avoid building any special stack for all
the contents in a single directory.
This allows for
- no need to remember the entire list of entries per directory
before applying the required functions
- no need to wait for entire readdir() call to finish before
applying the required functions
To avoid large delays in metacache cleanup, use rename
instead of recursive delete calls, renames are cheaper
move the content to minioMetaTmpBucket and then cleanup
this folder once in 24hrs instead.
If the new cache can replace an existing one, we should
let it replace since that is currently being saved anyways,
this avoids pile up of 1000's of metacache entires for
same listing calls that are not necessary to be stored
on disk.
Additional cases handled
- fix address situations where healing is not
triggered on failed writes and deletes.
- consider object exists during listing when
metadata can be successfully decoded.
Harshavardhana
Klaus Post