We use cache to avoid policing the same object multiple times in a short
time span (< 30 seconds). If we have 200_000 objects in a blobstor, it is a bit useless
-- if it takes 1 second to process an object and we have `replicator.pool_size: 20`
in config, the next iteration will happen in 10_000 second which is much
larger than 30 second. However we still consume a lot of memory, so it
makes sense to use saner default.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>