The HCX Multi-Site Service Mesh was released in experimental mode with the R114 HCX service update in early February, and initially supported greenfield implementations. The R116 HCX service update in mid-March added the ability to upgrade an existing Interconnect to the Multi-Site Service Mesh configuration, and that addition to the HCX service is what this post is all about.

Service Mesh is a VMware homonym worth clarifying:
There is the HCX Multi-Site Service Mesh, the modern HCX Interconnect platform, and the subject of this post, which is distinct and unrelated to the NSX Service Mesh.

Why upgrade an existing Interconnect to the Multi-Site Service Mesh?

The Multi-Site Service Mesh has several benefits:

• Flexible Network wiring that supports complex wiring topologies (dedicated uplink interfaces, multiple uplink interfaces, dedicated management, vMotion and replication interfaces) or simple one-arm configurations (and every variation in-between).
• Deployment Datastore pools. If the datastores are running out of space, they can be added or removed from the pool. With the current release HCX will use additional datastores when the primary datastore does not have sufficient space.
• Service Mesh deployment configurations can be edited and synchronized. Previously changes required the Interconnect appliances to be ripped out and replaced with the changes.
• Migration appliance scale. It is possible to deploy a single Interconnect Service Mesh for all clusters in the vCenter Server, and it is also possible to deploy a Service Mesh per cluster to scale out the migration capability.
• The Service Mesh interface provides Site to Site diagrams, depicting the deployment topology.
• A new task pane provides improved operational detail.
• Interface improvements for day-2 operations (multi-appliance selection, etc).

Most importantly, the redesigned Interconnect Service Mesh provides a foundational platform for upcoming features. Said features will not be seen with the previous Interconnect.

Also, there are several provisioning improvements that are less evident with the Interconnect Upgrade to Service Mesh path (vs. a greenfield implementation) but they are worth mentioning. For better context, the “Pre-Service Mesh” Interconnect provisioning process involved two main things:

• First – creating the Interconnect Configuration (a definition of Compute, Storage, Network resources) on the HCX Cloud Manager in the destination environment.

• Second – enabling and configuring HCX services, all the required parameters on-the-fly, and following the deployment of those services to completion, as one monolithic operation using the HCX plugin in the source environment.
  
  Ideally services deploy, otherwise repeat the second operation from scratch.

The Multi-Site Service Mesh improves the provisioning process in multiple ways:

• On-the-fly configurations are gone, replaced with Compute Profiles (CP), Network Profiles and HCX Service definitions.
• CP creation is decoupled from the Service Mesh creation (the instantiation of the Interconnect), so deployment configurations can be planned.
• A CP can be used with multiple Service Mesh configurations. This means connecting to a new HCX remote site can use a previously planned deployment allocation.
• Service Mesh deployments are symmetrical. CP creation is the same in the source and destination HCX Manager systems.
• Parallel execution makes provisioning faster (Less than 5 minutes. Previously around 15 minutes.

In most cases, it will make sense to adopt the change. An exception may be a datacenter decom project with tight migration timelines, and with dense migration waves well underway.

How to Upgrade the Interconnect

Suggested Pre-checks:

• Open the HCX Appliance Management interface (:9443) and verify the system to system connections (HCX to vCenter Server, NSX|VCD|RMQ if applicable) are green.
• Open the HCX plugin and verify the HCX Site Pairs are connected.
• Open the HCX CCLI and use list to verify that appliances are connected.

Upgrade Procedure:

• Click Upgrade to the Multi-Site Service Mesh 
• The following message is displayed:
  
  Upgrade will transform the current ‘HCX components’ configuration into ‘Multi-Site Service Mesh’ configuration. This operation is not reversible. ‘Multi-Site Service Mesh’ is a new and better way of managing the interconnect configuration. Soon the support for managing the interconnect configuration using ‘HCX components’ will be discontinued. 
  
  The upgrade operation may require redeploying the service appliances. Any migration, DR or network extension operations in progress may be affected. Kindly confirm that there is no migration, DR, Network Extension operation in progress before proceeding with the upgrade. 

• Click YES to continue.
• The Interconnect upgrade will transition through these states:
  Initiated upgrade of compute and network configuration on endpoints…
  Created service meshes.
  Initiated upgrade of appliances configuration on endpoints…
  Backing up HCX Components and removing…

• In the HCX Components view, the services will disappear:

• After a short interval, the interface will display an Upgrade Successful message:

• The Multi-Site Service Mesh interface will display the converted objects:

And that is it! Thanks for reading. 🙌🏼