From: Zac Dover Date: Wed, 5 Jul 2023 17:36:52 +0000 (+1000) Subject: doc/radosgw: add Zonegroup purpose X-Git-Tag: v17.2.7~265^2 X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=b5cda59fd723979d4d4d9d6e0f272fd4cd7049e2;p=ceph.git doc/radosgw: add Zonegroup purpose Add a note about the telos of zonegroups. The information added in this commit was originally sent to ceph-users by Casey Bodley on 30 Jun 2023 in response to a question from Yixin Jin. Alexander Patrakov then suggested that Casey's response should be added to doc/radsogw/multisite.rst. Co-authored-by: Casey Bodley Co-authored-by: Anthony D'Atri Signed-off-by: Zac Dover (cherry picked from commit 5c46a1a00962918c885e434986d0f846c3ee4730) --- diff --git a/doc/radosgw/multisite.rst b/doc/radosgw/multisite.rst index 43d28b456636e..38acc866fb4e3 100644 --- a/doc/radosgw/multisite.rst +++ b/doc/radosgw/multisite.rst @@ -46,6 +46,26 @@ configurations for the Ceph Object Gateway: a global object namespace. This global object namespace ensures unique object IDs across zonegroups and zones. + It can be useful to create multiple zonegroups in cases where isolation of + the RADOS object data is desirable when those datasets exist in a shared + namespace of users and buckets. It might be that you have several connected + sites that share storage, but only require a single backup for purposes of + disaster recovery. In such a case, it could make sense to create several + zonegroups with only two zones each to avoid replicating all objects to all + zones. + + In other cases, it might make more sense to isolate RADOS object data in + separate realms, with each having a single zonegroup. Zonegroups provide + flexibility by making it possible to control the isolation of data and + metadata separately. + + Metadata (for example, users and buckets) replicates to all zonegroups, but + object data replicates only within a single zonegroup. A bucket is "owned" by + the zonegrup that created it (except in cases in which the + ``LocationConstraint`` has overridden this upon creation of the bucket). Any + request for data in that bucket that are sent to other zonegroups redirect to + the zonegroup where the bucket resides. + - **Multiple Realms:** Beginning with the Kraken release, the Ceph Object Gateway supports "realms", which are containers for zonegroups. Realms make it possible to set policies that apply to multiple zonegroups. Realms have a @@ -55,6 +75,7 @@ configurations for the Ceph Object Gateway: realm can have a configuration that is distinct from the configuration of other realms). + Diagram - Replication of Object Data Between Zones --------------------------------------------------