Upgrading Connection Servers in Parallel

If your deployment has multiple Connection Servers, you can upgrade the Connection Servers in parallel to save down time.

Before you perform an upgrade of multiple Connection Servers in parallel, you must verify the following prerequisites.

• Verify that there are no issues with Horizon LDAP replication. For a successful upgrade of multiple Connection Servers in parallel, the local Horizon LDAP instance and the global Horizon LDAP instance in the Connection Server cluster must be in a consistent state. The Connection Server installer blocks the upgrade process if there are any issues with Horizon LDAP replication.

  The local Horizon LDAP instance is created during installation of the first Connection Server and holds configuration data for the Connection Server cluster, which includes the Connection Server and replica servers. This local Horizon LDAP instance is replicated across all Connection Servers within a single cluster.

  The global Horizon LDAP instance is created when you set up the Cloud Pod Architecture environment and holds configuration data for a federation of clusters or pods. This global Horizon LDAP instance is replicated across all Connection Servers in the federation.

  To determine if there are any issues replicating the local Horizon LDAP instance, run the following command:

  repadmin.exe /showrepl localhost:389

  To determine if there are any issues replicating the global Horizon LDAP instance in a Cloud Pod Architecture environment, run the following command:

  repadmin.exe /showrepl localhost:22389

  For additional troubleshooting information, see Troubleshooting Errors During Upgrade and Installation of Connection Servers.

• Upgrade one Connection Server to determine if there are any issues with Horizon LDAP replication. After you resolve any errors during the upgrade process, you can proceed to upgrade multiple Connection Servers in parallel.
• Bring up all the Horizon LDAP nodes in the Connection Server cluster before the upgrade. This ensures that the schema master node is available on the cluster. The upgrade fails if the schema master node is removed from the cluster. If the schema master node is removed, you can use the vdmadmin -X command to make the current node the schema master node. For more information about the vdmadmin -X command, see "Detecting and Resolving LDAP Entry and Schema Collisions Using the -X Option" in the Horizon Administration document.
• You can upgrade all Connections Servers in three pods at a time.

Use the following process to upgrade all Connection Servers in a pod in parallel:

1. Upgrade all Connection Server instances in the pods. See Upgrade Connection Servers in a Replicated Group.
   Note: The Connection Server installer will pause for a longer time than usual at the last step because it waits for all the services to start.