diff --git a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
index 0c10451add4c..ccbcb0a9a2ab 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
@@ -519,6 +519,25 @@
           because Python 2 is being retired from nixpkgs.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          Services in the <literal>hadoop</literal> module previously
+          set <literal>openFirewall</literal> to true by default. This
+          has now been changed to false. Node definitions for multi-node
+          clusters would need <literal>openFirewall = true;</literal> to
+          be added to to hadoop services when upgrading from NixOS
+          21.11.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          <literal>services.hadoop.yarn.nodemanager</literal> now uses
+          cgroup-based CPU limit enforcement by default. Additionally,
+          the option <literal>useCGroups</literal> was added to
+          nodemanagers as an easy way to switch back to the old
+          behavior.
+        </para>
+      </listitem>
       <listitem>
         <para>
           The <literal>wafHook</literal> hook now honors
@@ -1071,6 +1090,33 @@
           using the PyPy interpreter were added.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          Some improvements have been made to the
+          <literal>hadoop</literal> module:
+        </para>
+        <itemizedlist spacing="compact">
+          <listitem>
+            <para>
+              A <literal>gatewayRole</literal> option has been added,
+              for deploying hadoop cluster configuration files to a node
+              that does not have any active services
+            </para>
+          </listitem>
+          <listitem>
+            <para>
+              Support for older versions of hadoop have been added to
+              the module
+            </para>
+          </listitem>
+          <listitem>
+            <para>
+              Overriding and extending site XML files has been made
+              easier
+            </para>
+          </listitem>
+        </itemizedlist>
+      </listitem>
       <listitem>
         <para>
           If you are using Wayland you can choose to use the Ozone
diff --git a/nixos/doc/manual/release-notes/rl-2205.section.md b/nixos/doc/manual/release-notes/rl-2205.section.md
index b9402ba5f9dd..6d91ee1dffc8 100644
--- a/nixos/doc/manual/release-notes/rl-2205.section.md
+++ b/nixos/doc/manual/release-notes/rl-2205.section.md
@@ -223,6 +223,14 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - The MoinMoin wiki engine (`services.moinmoin`) has been removed, because Python 2 is being retired from nixpkgs.
 
+- Services in the `hadoop` module previously set `openFirewall` to true by default.
+  This has now been changed to false. Node definitions for multi-node clusters would need
+  `openFirewall = true;` to be added to to hadoop services when upgrading from NixOS 21.11.
+
+- `services.hadoop.yarn.nodemanager` now uses cgroup-based CPU limit enforcement by default.
+  Additionally, the option `useCGroups` was added to nodemanagers as an easy way to switch
+  back to the old behavior.
+
 - The `wafHook` hook now honors `NIX_BUILD_CORES` when `enableParallelBuilding` is not set explicitly. Packages can restore the old behaviour by setting `enableParallelBuilding=false`.
 
 - `pkgs.claws-mail-gtk2`, representing Claws Mail's older release version three, was removed in order to get rid of Python 2.
@@ -391,6 +399,11 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - The `writers.writePyPy2`/`writers.writePyPy3` and corresponding `writers.writePyPy2Bin`/`writers.writePyPy3Bin` convenience functions to create executable Python 2/3 scripts using the PyPy interpreter were added.
 
+- Some improvements have been made to the `hadoop` module:
+  - A `gatewayRole` option has been added, for deploying hadoop cluster configuration files to a node that does not have any active services
+  - Support for older versions of hadoop have been added to the module
+  - Overriding and extending site XML files has been made easier
+
 - If you are using Wayland you can choose to use the Ozone Wayland support
   in Chrome and several Electron apps by setting the environment variable
   `NIXOS_OZONE_WL=1` (for example via