On Tue, Sep 12, 2023 at 07:13:13PM +0200, Matthias Ferdinand wrote:
On Mon, Sep 11, 2023 at 02:37:59PM -0400, Matt Benjamin wrote:
Yes, it's also strongly consistent. It's also last writer wins, though, so two clients somehow permitted to contend for updating policy could overwrite each other's changes, just as with objects.
this would be a tremendous administrative bonus, but could also be a caching/performance problem. Amazon explicitly says they have eventual consistency for caching reasons: https://docs.aws.amazon.com/IAM/latest/UserGuide/troubleshoot_general.html#t... For Dell ECS I don't seem to find it mentioned in their docs, but they too are eventually consistent. I guess the bucket policies in Ceph get written to special rados objects (strongly consistent by design), but how are rgw daemons notified about these updates for immediate effect? Or do rgw daemons re-read the bucket policy for each and every request to this bucket? thanks in advance Matthias
On Mon, Sep 11, 2023 at 2:21 PM Matthias Ferdinand <mf+ml.ceph@mfedv.net> wrote:
Hi,
while I don't currently use rgw, I still am curious about consistency guarantees.
Usually, S3 has strong read-after-write consistency guarantees (for requests that do not overlap). According to https://docs.ceph.com/en/latest/dev/radosgw/bucket_index/ in Ceph this is also true for per-object ACLs.
Is there also a strong consistency guarantee for (bucket) policies? The documentation at https://docs.ceph.com/en/latest/radosgw/bucketpolicy/ apparently does not say anything about this.
How would multiple rgw instances synchronize a policy change? Is this effective immediate with strong consistency or is there some propagation delay (hopefully on with some upper bound)?
Best regards Matthias _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
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