MCP in Degraded State due to etcdserver: request is too large during cluster upgrade.

Issue

• Master MachineConfigPool(MCP) is in degraded state during OpenShift Container Platform upgrade between minor version (e.g., 4.14 to 4.16) due to the machineconfig size is exceeding the etcd limit of 1.5MB.

• Machine Config Operator stuck into degraded state with following message:

    message: 'Failed to resync 4.15.50 because: error during syncRequiredMachineConfigPools:
      [context deadline exceeded, failed to update clusteroperator: [client rate limiter
      Wait returned an error: context deadline exceeded, error MachineConfigPool master
      is not ready, retrying. Status: (pool degraded: true total: 3, ready 3, updated:
      3, unavailable: 0)]]'
    reason: RequiredPoolsFailed
    status: "True"
    type: Degraded
  

• MCP stuck into degraded state with the following error message:

    message: 'Failed to render configuration for pool master: etcdserver: request
      is too large'
    reason: ""
    status: "True"
    type: RenderDegraded