doc/glossary: add "Period" to glossary

Add definition for "period" to glossary.

Signed-off-by: Zac Dover <zac.dover@proton.me>
(cherry picked from commit bd9bc3adb3960385615fe79ea83809396a19dae0)

diff --git a/doc/glossary.rst b/doc/glossary.rst
index 2149a76e6dab982f67c79be3bbbdec6810c44eb3..091d332629f03f7fad6fd149a89b66ac7b2e0e09 100644 (file)
--- a/doc/glossary.rst
+++ b/doc/glossary.rst
@@ -271,6 +271,12 @@
                 This is the unique identifier of an OSD. This term is used
                 interchangeably with ``fsid``
 
+        Period
+                In the context of :term:`RGW`, a period is the configuration
+                state of the :term:`Realm`. The period stores the configuration
+                state of a multi-site configuration. When the period is updated,
+                the "epoch" is said thereby to have been changed.
+
        :ref:`Pool<rados_pools>`
                A pool is a logical partition used to store objects.