I recently did a project with a client which involves a fairly complex design on their Platform Services Controller, I shall not be elaborating the details of the project, but the project required my team to relook into the options available under the supported topologies of PSC under vSphere 6.5.
"What is VMware Platform Services Controller (PSC)"
VMware PSC is a new service in vSphere 6.0 as a mechanism to simplify and centralize common vSphere infrastructure services. It handles the infrastructure security functions such as vCenter SSO, VMware Certificate Authority (VMCA), licensing, server reservation and registration services. PSC is available on both the Windows vCenter Server ISO or within the vCenter Server Appliance (VCSA) ISO. (For more info, refer to VMware KB article https://kb.vmware.com/s/article/2113115)
PSC includes a set of common infra services:
VMware vCenter Single Sign-On
VMware License Server
Lookup Service
Vmware Certificate Authority
Certificate Store
VMware Directory Services
"What happens when PSC goes down?"
This is one of the common questions raised by clients. When a PSC server is down, you will not be able to log in to vCenter Server or any VMware products that depends on it. Existing connections and user sessions to the vCenter Server remains active, and the vCenter Server services remains up and running. If when the PSC is down, and vCenter Server's services are restarted, vCenter Server is unable to fully start until PSC's services are restored or vCenter is repointed to an working PSC in the same vSphere Domain.
Supported and deprecated topologies for VMware vSphere 6.5
From experience, below are some of the commonly adopted topologies.
For the full range of supported architecture, refer to VMware KB article https://kb.vmware.com/s/article/2147672.
Long story short, in my opinion, below are the rule of thumb.
- Embedded PSC design is only support for single vCenter Server. If you have more than 1 vCenter Server, only option is external PSC.
- For multi-PSC and multi-vCenter design, it is recommended to deploy a 3rd party load balancer.
- In the absence of load balancer, for multi-PSC and multi-vCenter designs, in the event of a PSC failover, vCenter Servers will need to be manually repointed to the functioning PSC.
Note:
- When configuring PSC HA, the load balanced pair are required to be the same type; it is not supported to mix Appliance-Base and Widnows-Based PSCs in the same load balanced pair. (VMware KB article https://kb.vmware.com/s/article/2113115)
- During the migration or upgrade process, a mixed environment is supported
"What do you think?"
Let me know if you think there is any important/useful details I have missed in the above write up.
