Large clusters
This section describes a validated MOSK cluster architecture that is capable of handling 10,000 instances under a single control plane.
Hardware characteristics
Note
If a node role requires a Local Volume Provisioner (LVP) disk, place
it on a separate physical device from the system disk that contains /.
Mirantis does not recommend creating the LVP volume on the system disk.
For disk roles and sizes, see Host operating system disk layout.
Cluster architecture
Cluster validation
The architecture validation is performed by means of simultaneous creation of multiple OpenStack resources of various types and execution of functional tests against each resource. The amount of resources hosted in the cluster at the moment when a certain threshold of non-operational resources starts being observed, is described below as cluster capacity limit.
Note
A successfully created resource has the Active status in the API
and passes the functional tests, for example, its floating IP address is
accessible. The MOSK cluster is considered to be able to
handle the created resources if it successfully performs the LCM operations
including the OpenStack services restart, both on the control and data
plane.
Note
The key limiting factor for creating more OpenStack objects in this illustrative setup is hardware resources (vCPU and RAM) available on the compute nodes.