Windows Patches & Upgrades
This section aims to help you achieve zero downtime for your NCache deployment when applying Windows patches.
How to Apply Windows Patches on NCache Server
Note
Please remember that you should always perform maintenance, patching, or upgrading activities, such as applying Windows patches to one node at a time.
The required steps to apply Windows patches on NCache server are as follows:
1. Stop Cache
Stop the cache on the server node being patched. If this node is part of multiple cache clusters, stop the cache on this node for all the cache clusters. This will start the state transfer process and data will be re-balanced on the other nodes available in the cluster.
Note
If all caches on the server node aren’t stopped before applying NCache or Windows patches, it could lead to a split brain scenario. Make sure all caches running on the server node are stopped so that the node gracefully leaves each cache cluster before proceeding.
2. Stop NCache Service
Stop NCache Service on this server and change the service start-up type from Automatic to Manual to manually start NCache Service after reboot. You can use our documentation to achieve this.
3. Apply Patch
Apply required Windows patches/updates. Complete all the maintenance tasks running on this machine and then reboot the server.
4. Restart NCache Service
After successful completion of step 3, now restart the NCache Service and also change the service start-up type back to Automatic for normal usage.
5. Start Cache
Now start the cache manually from the NCache Management Center if auto-start is not enabled.
Refresh the cache cluster from the NCache Management Center to view this node as an active node in the cluster. Furthermore, you can see data being transferred to the rejoining cache node by monitoring the cache through the NCache performance counters.
Note
You can skip this step if auto-start is already enabled.
Perform the same steps for the other nodes in your environment. It is a good practice to start NCache Service manually once all the patches are fully applied and maintenance work has been completed on your server.
