Merge pull request #107934 from jonels-msft/compute-scaling

Can now adjust vCores via the UI

Author: v-shils

articles/postgresql/howto-hyperscale-alert-on-metric.md

@@ -5,7 +5,7 @@ author: jonels-msft
 ms.author: jonels
 ms.service: postgresql
 ms.topic: conceptual
-ms.date: 2/18/2020
+ms.date: 3/16/2020
 ---
 
 # Use the Azure portal to set up alerts on metrics for Azure Database for PostgreSQL - Hyperscale (Citus)
@@ -96,7 +96,7 @@ As the disk approaches its space limit, try these techniques to get more free sp
 
 * Review data retention policy. Move older data to cold storage if feasible.
 * Consider [adding nodes](howto-hyperscale-scaling.md#add-worker-nodes) to the server group and rebalancing shards. Rebalancing distributes the data across more computers.
-* Consider [growing the capacity](howto-hyperscale-scaling.md#increase-vcores) of worker nodes. Each worker can have up to 2 TiB of storage. However adding nodes should be attempted before resizing nodes because adding nodes completes faster.
+* Consider [growing the capacity](howto-hyperscale-scaling.md#increase-or-decrease-vcores-on-nodes) of worker nodes. Each worker can have up to 2 TiB of storage. However adding nodes should be attempted before resizing nodes because adding nodes completes faster.
 
 ### CPU usage
 

articles/postgresql/howto-hyperscale-scaling.md

@@ -5,7 +5,7 @@ author: jonels-msft
 ms.author: jonels
 ms.service: postgresql
 ms.topic: conceptual
-ms.date: 12/17/2019
+ms.date: 3/16/2020
 ---
 
 # Scale a Hyperscale (Citus) server group
@@ -45,13 +45,24 @@ The `rebalance_table_shards` function rebalances all tables in the
 argument. Thus you do not have to call the function for every distributed
 table, just call it on a representative table from each colocation group.
 
-## Increase vCores
+## Increase or decrease vCores on nodes
 
-In addition to adding new nodes, you can increase the capabilities of existing
-nodes. This feature is currently in preview — to request increased vCores for
+> [!NOTE]
+> This feature is currently in preview. To request a change in vCores for
 nodes in your server group, please [contact Azure
 support](https://portal.azure.com/?#blade/Microsoft_Azure_Support/HelpAndSupportBlade).
 
+In addition to adding new nodes, you can increase the capabilities of existing
+nodes. Adjusting compute capacity up and down can be useful for performance
+experiments as well as short- or long-term changes to traffic demands.
+
+To change the vCores for all worker nodes, adjust the **vCores** slider under
+**Configuration (per worker node)**. The coordinator node's vCores can be
+adjusted independently. Click the **Change configuration** link under
+**coordinator node**. A dialog will appear with sliders for the vCores and
+Storage capacity of the coordinator. Change the sliders as desired and select
+**OK**.
+
 ## Next steps
 
 Learn more about server group [performance