docs(scaling): updates scaling section to instruct how to scale ssh and celery

docs/source/configuration/scaling-rhodecode.rst

@@ -4,6 +4,10 b''
 Scaling to handle more traffic
 ==============================
 
+
+scaling http traffic
+++++++++++++++++++++
+
 In case for bigger setups docker-compose can scale more rhodecode/vcsserver workers:
 Adjust the .custom/docker-compose-apps.override.yaml file and change `replicas: NUM`
 
@@ -30,3 +34,41 b' Then scale docker replicas without any downtime using this command'
 .. code-block:: bash
 
   ./rcstack stack rhodecode up --detach --no-recreate --scale rhodecode=4 --scale vcsserver=4
+
+
+
+scaling ssh traffic
++++++++++++++++++++
+
+ssh workers can scale independently from the http traffic handled by rhodecode/vcsserver. To scale for more ssh
+traffic, increase replicas for sshd service
+
+.. code-block:: yaml
+
+    services:
+      sshd:
+        deploy:
+          # set number of instances of services to be spawned on stack start
+          replicas: 4
+
+
+scaling celery workers
+++++++++++++++++++++++
+
+celery workers can scale independently from the http traffic handled by rhodecode/vcsserver. To scale for more celery
+task processing capabilities, increase replicas for celery service.
+
+.. code-block:: yaml
+
+    celery:
+      sshd:
+        deploy:
+          # set number of instances of services to be spawned on stack start
+          replicas: 4
+
+
+.. note::
+
+    Celery already has an autoscaler defined by the command argument called `"--autoscale=20,2".`
+    This means that there are min of 2 processes per worker that can scale upto 20 if there are more tasks to process.
+    Scaling replicas means the maximum task processing capacity would be defined by replicas * maximum autoscale number.