doc/rgw: refine 1-50 of multisite.rst

Refine the English in the first fifty lines of multisite.rst. This is
part of a project whose goal is the creation of a document that will
impart a good aerial view of RGW to a first-time reader in the minimum
number of words.

Co-authored-by: Anthony D'Atri <anthony.datri@gmail.com>
Signed-off-by: Zac Dover <zac.dover@proton.me>
(cherry picked from commit 6721196ff129b00d9dea3515fbaaacde8f84eaea)

diff --git a/doc/radosgw/multisite.rst b/doc/radosgw/multisite.rst
index dcdf5d3147e752a83d67e7276f91b7dd3b3dd7ab..561d7bb2996b1c3e90deed480d4d03736ac006e5 100644 (file)
--- a/doc/radosgw/multisite.rst
+++ b/doc/radosgw/multisite.rst
@@ -6,33 +6,39 @@ Multi-Site
 
 .. versionadded:: Jewel
 
-A single zone configuration typically consists of one zone group containing one
-zone and one or more `ceph-radosgw` instances where you may load-balance gateway
-client requests between the instances. In a single zone configuration, typically
-multiple gateway instances point to a single Ceph storage cluster. However, Kraken
-supports several multi-site configuration options for the Ceph Object Gateway:
-
-- **Multi-zone:** A more advanced configuration consists of one zone group and
-  multiple zones, each zone with one or more `ceph-radosgw` instances. Each zone
-  is backed by its own Ceph Storage Cluster. Multiple zones in a zone group
-  provides disaster recovery for the zone group should one of the zones experience
-  a significant failure. In Kraken, each zone is active and may receive write
-  operations. In addition to disaster recovery, multiple active zones may also
-  serve as a foundation for content delivery networks.
-
-- **Multi-zone-group:** Formerly called 'regions', Ceph Object Gateway can also
-  support multiple zone groups, each zone group with one or more zones. Objects
-  stored to zones in one zone group within the same realm as another zone
-  group will share a global object namespace, ensuring unique object IDs across
-  zone groups and zones.
-
-- **Multiple Realms:** In Kraken, the Ceph Object Gateway supports the notion
-  of realms, which can be a single zone group or multiple zone groups and
-  a globally unique namespace for the realm. Multiple realms provide the ability
-  to support numerous configurations and namespaces.
-
-Replicating object data between zones within a zone group looks something
-like this:
+A single-zone configuration typically consists of (1) one "zone group", which
+contains one zone and (2) one or more `ceph-radosgw` instances between which
+gateway client requests are load-balanced. In a typical single-zone
+configuration, multiple gateway instances make use of a single Ceph storage
+cluster.  
+
+Beginning with the Kraken release, Ceph supports several multi-site
+configurations for the Ceph Object Gateway:
+
+- **Multi-zone:** A more advanced topology, the "multi-zone" configuration, is
+  possible. This multi-zone configuration consists of one zone group and
+  multiple zones, with each zone comprising one or more `ceph-radosgw`
+  instances. Each zone is backed by its own Ceph Storage Cluster. The presence
+  of multiple zones in a given zone group provides disaster recovery for that
+  zone group in the event that one of the zones experiences a significant
+  failure. Beginning with Kraken, each zone is active and can receive write
+  operations. A multi-zone configuration with multiple active zones enhances
+  disaster recovery and can also be used as a foundation for content delivery
+  networks. 
+
+- **Multi-zone-groups:** Formerly called 'regions'. Ceph Object Gateway
+  supports multiple zone groups, with each zone group containing one or more
+  zones. Objects that are stored to zones in one zone group within the same
+  realm as another zone group share a global object namespace, which ensures
+  unique object IDs across zone groups and zones.
+
+- **Multiple Realms:** Beginning with the Kraken Ceph release, the Ceph Object
+  Gateway supports something called "realms". Realms have a globally unique
+  namespace and can be a either a single-zone group or multiple-zone groups.
+  Multiple realms provide support for multiple configurations and namespaces.
+
+The replication of object data between zones within a zone group looks
+something like this:
 
 .. image:: ../images/zone-sync2.png
    :align: center