Module - tripleo_derive_hci_parameters

This module provides for the following ansible plugin:

  • tripleo_derive_hci_parameters

Module Documentation

When collocating Ceph OSDs on Nova Compute hosts (hyperconverged or hci) the Nova Scheduler does not take into account the CPU/Memory needs of the OSDs. This module returns recommended NovaReservedHostMemory and NovaCPUAllocationRatio parmaters so that the host reseves memory and CPU for Ceph. The values are based on workload description, deployment configuration, and Ironic data. The workload description is the expected average_guest_cpu_utilization_percentage and average_guest_memory_size_in_mb.



Map from key environment_parameters from stack_data. Used to determine number of OSDs in deployment per role


TripleO role name whose parameters are being derived


Output of the tripleo_get_introspected_data module. Used to determine available memory and CPU of each instance from any role with the CephOSD service


Percentage of CPU utilization expected for average guest, e.g. 99 means 99% and 10 means 10%


Amount of memory in MB required by the average guest


any previously derived parameters which should be included in the final result


Path to file new where resultant derived parameters will be written; result will be valid input to TripleO client, e.g. /home/stack/derived_paramaters.yaml


If new_heat_environment_path already exists and append_new_heat_environment_path is true, then append new content to the existing new_heat_environment_path instead of overwriting a new version of that file.


Path to file new where a report on how HCI paramters were derived be written, e.g. /home/stack/hci_derived_paramaters.txt


John Fulton (fultonj)

Example Tasks

- name: Add Derived HCI parameters to existing derived parameters for ComputeHCI role
    tripleo_environment_parameters: '{{ tripleo_environment_parameters }}'
    introspection_data: '{{ hw_data }}'
    derived_parameters: '{{ derived_parameters }}'
    tripleo_role_name: ComputeHCI
    average_guest_cpu_utilization_percentage: 90
    average_guest_memory_size_in_mb: 8192
    new_heat_environment_path: /home/stack/hci_result.yaml
    report_path: /home/stack/hci_report.txt
  register: derived_parameters_result
- name: Show derived HCI Memory result
    msg: "{{ derived_parameters_result['derived_parameters']['ComputeHCIParameters']['NovaReservedHostMemory']\
      \ }}"
- name: Show derived HCI CPU result
    msg: "{{ derived_parameters_result['derived_parameters']['ComputeHCIParameters']['NovaCPUAllocationRatio']\
      \ }}"