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.
with missing nextMarker with delimiter based listing,
top level prefixes beyond 4500 or max-keys value
wouldn't be sent back for client to ask for the next
batch.
reproduced at a customer deployment, create prefixes
as shown below
```
for year in $(seq 2017 2020)
do
for month in {01..12}
do for day in {01..31}
do
mc -q cp file myminio/testbucket/dir/day_id=$year-$month-$day/;
done
done
done
```
Then perform
```
aws s3api --profile minio --endpoint-url http://localhost:9000 list-objects \
--bucket testbucket --prefix dir/ --delimiter / --max-keys 1000
```
You shall see missing NextMarker, this would disallow listing beyond max-keys
requested and also disallow beyond 4500 (maxKeyObjectList) prefixes being listed
because client wouldn't know the NextMarker available.
This PR addresses this situation properly by making the implementation
more spec compatible. i.e NextMarker in-fact can be either an object, a prefix
with delimiter depending on the input operation.
This issue was introduced after the list caching changes and has been present
for a while.
X-Minio-Replication-Delete-Status header shows the
status of the replication of a permanent delete of a version.
All GETs are disallowed and return 405 on this object version.
In the case of replicating delete markers.
X-Minio-Replication-DeleteMarker-Status shows the status
of replication, and would similarly return 405.
Additionally, this PR adds reporting of delete marker event completion
and updates documentation
Delete marker replication is implemented for V2
configuration specified in AWS spec (though AWS
allows it only in the V1 configuration).
This PR also brings in a MinIO only extension of
replicating permanent deletes, i.e. deletes specifying
version id are replicated to target cluster.
Design: https://gist.github.com/klauspost/025c09b48ed4a1293c917cecfabdf21c
Gist of improvements:
* Cross-server caching and listing will use the same data across servers and requests.
* Lists can be arbitrarily resumed at a constant speed.
* Metadata for all files scanned is stored for streaming retrieval.
* The existing bloom filters controlled by the crawler is used for validating caches.
* Concurrent requests for the same data (or parts of it) will not spawn additional walkers.
* Listing a subdirectory of an existing recursive cache will use the cache.
* All listing operations are fully streamable so the number of objects in a bucket no
longer dictates the amount of memory.
* Listings can be handled by any server within the cluster.
* Caches are cleaned up when out of date or superseded by a more recent one.
