cf1744373f
Add new option to tripleo_derive_hci_parameters module so that if both the average_guest_cpu_utilization_percentage and the average_guest_memory_size_in_mb are not passed, then a simpler calculation is performed which computes the required memory for the Ceph OSDs. It is preferable for the user to pass the expected workload but if this value is unknown it is still better to at least reserve the bare minimum in memory for the OSDs so that they do not get shutdown from an OOM error. Change-Id: I68ad3783d3e0bf47fd63ab79f6ea0b0655c751c1
521 lines
22 KiB
Python
521 lines
22 KiB
Python
#!/usr/bin/env python
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# Copyright 2020 Red Hat, Inc.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""Derive paramters for HCI (hyper-converged) deployments"""
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import re
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import yaml
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from ansible.module_utils.basic import AnsibleModule
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ANSIBLE_METADATA = {
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'metadata_version': '0.1',
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'status': ['preview'],
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'supported_by': 'community'
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}
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DOCUMENTATION = '''
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---
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module: tripleo_derive_hci_parameters
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short_description: Tune Nova scheduler parameters to reserve resources for collocated Ceph OSDs
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description:
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- "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."
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options:
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tripleo_environment_parameters:
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description: Map from key environment_parameters from output of the tripleo_get_flatten_stack module stack_data. Used to determine number of OSDs in deployment per role
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required: True
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type: map
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tripleo_role_name:
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description: TripleO role name whose parameters are being derived
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required: True
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type: string
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introspection_data:
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description: 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
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required: True
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type: map
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average_guest_cpu_utilization_percentage:
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description: Percentage of CPU utilization expected for average guest, e.g. 99 means 99% and 10 means 10%
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required: False
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type: int
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default: 0
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average_guest_memory_size_in_mb:
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description: Amount of memory in MB required by the average guest
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required: False
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type: int
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default: 0
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derived_parameters:
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description: any previously derived parameters which should be included in the final result
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required: False
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type: map
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new_heat_environment_path:
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description: 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
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required: False
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type: str
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report_path:
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description: Path to file new where a report on how HCI paramters were derived be written, e.g. /home/stack/hci_derived_paramaters.txt
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required: False
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type: str
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author:
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- John Fulton (fultonj)
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'''
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EXAMPLES = '''
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- name: Add Derived HCI parameters to existing derived parameters for ComputeHCI role
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tripleo_derive_hci_parameters:
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tripleo_environment_parameters: "{{ tripleo_environment_parameters }}"
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introspection_data: "{{ hw_data }}"
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derived_parameters: "{{ derived_parameters }}"
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tripleo_role_name: "ComputeHCI"
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average_guest_cpu_utilization_percentage: 90
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average_guest_memory_size_in_mb: 8192
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new_heat_environment_path: "/home/stack/hci_result.yaml"
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report_path: "/home/stack/hci_report.txt"
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register: derived_parameters_result
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- name: Show derived HCI Memory result
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debug:
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msg: "{{ derived_parameters_result['derived_parameters']['ComputeHCIParameters']['NovaReservedHostMemory'] }}"
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- name: Show derived HCI CPU result
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debug:
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msg: "{{ derived_parameters_result['derived_parameters']['ComputeHCIParameters']['NovaCPUAllocationRatio'] }}"
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- name: Update deployment plan with derived_parameters
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tripleo_plan_parameters_update:
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container: "{{ plan }}"
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parameter_key: 'derived_parameters'
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parameters: "{{ derived_parameters_result['derived_parameters'] }}"
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validate: true
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'''
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RETURN = '''
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message:
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description: A description of the HCI derived parameters calculation or an error message
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type: str
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returned: always
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derived_parameters:
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description: map with derived hci paramters and any previously derived parameters
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required: False
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type: map
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'''
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MB_PER_GB = 1024
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def derive(mem_gb, vcpus, osds, average_guest_memory_size_in_mb=0,
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average_guest_cpu_utilization_percentage=0,
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mem_gb_per_osd=5, vcpus_per_osd=1.0, total_memory_threshold=0.8):
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"""
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Determines the recommended Nova scheduler values based on Ceph needs
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and described average Nova guest workload in CPU and Memory utilization.
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If expected guest utilization is not provided result is less accurate.
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Returns dictionary containing the keys: cpu_allocation_ratio (float),
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nova_reserved_mem_mb (int), message (string), failed (boolean).
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"""
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gb_overhead_per_guest = 0.5 # based on measurement in test environment
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# seed the result
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derived = {}
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derived['message'] = ""
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derived['failed'] = False
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if average_guest_memory_size_in_mb == 0 and \
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average_guest_cpu_utilization_percentage == 0:
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workload = False
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else:
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workload = True
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# catch possible errors in parameters
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if mem_gb < 1:
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msg = "Unable to determine the amount of physical memory "
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msg += "(no 'memory_mb' found in introspection_data)."
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derived['message'] += msg + "\n"
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derived['failed'] = True
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if vcpus < 1:
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msg = "Unable to determine the number of CPU cores. "
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msg += "Either no 'cpus' found in introspection_data or "
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msg += "NovaVcpuPinSet is not correctly set."
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derived['message'] += msg + "\n"
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derived['failed'] = True
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if osds < 1:
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msg = "No OSDs were found in deployment definition under CephAnsibleDisksConfig"
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derived['message'] += msg + "\n"
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derived['failed'] = True
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if average_guest_memory_size_in_mb < 0 and workload:
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msg = "If average_guest_memory_size_in_mb is used it must be greater than 0"
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derived['message'] += msg + "\n"
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derived['failed'] = True
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if average_guest_cpu_utilization_percentage < 0 and workload:
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msg = "If average_guest_cpu_utilization_percentage is used it must be greater than 0"
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derived['message'] += msg + "\n"
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derived['failed'] = True
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left_over_mem = mem_gb - (mem_gb_per_osd * osds)
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if left_over_mem < 0:
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msg = "There is not enough memory to run %d OSDs. " % (osds)
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msg += "%d GB RAM - (%d GB per OSD * %d OSDs) is < 0" % (mem_gb, mem_gb_per_osd, osds)
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derived['message'] += msg + "\n"
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derived['failed'] = True
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if derived['failed']:
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return derived
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# perform the calculation
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if workload:
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average_guest_size = average_guest_memory_size_in_mb / float(MB_PER_GB)
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average_guest_util = average_guest_cpu_utilization_percentage * 0.01
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number_of_guests = int(left_over_mem
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/ (average_guest_size + gb_overhead_per_guest))
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nova_reserved_mem_mb = MB_PER_GB * ((mem_gb_per_osd * osds)
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+ (number_of_guests * gb_overhead_per_guest))
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nonceph_vcpus = vcpus - (vcpus_per_osd * osds)
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guest_vcpus = nonceph_vcpus / average_guest_util
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cpu_allocation_ratio = guest_vcpus / vcpus
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else:
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nova_reserved_mem_mb = MB_PER_GB * (mem_gb_per_osd * osds)
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# save calculation results
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derived['nova_reserved_mem_mb'] = int(nova_reserved_mem_mb)
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if workload:
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derived['cpu_allocation_ratio'] = cpu_allocation_ratio
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# capture derivation details in message
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msg = "Derived Parameters results"
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msg += "\n Inputs:"
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msg += "\n - Total host RAM in GB: %d" % mem_gb
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msg += "\n - Total host vCPUs: %d" % vcpus
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msg += "\n - Ceph OSDs per host: %d" % osds
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if workload:
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msg += "\n - Average guest memory size in GB: %d" % average_guest_size
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msg += "\n - Average guest CPU utilization: %.0f%%" % \
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average_guest_cpu_utilization_percentage
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msg += "\n "
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msg += "\n Outputs:"
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if workload:
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msg += "\n - number of guests allowed based on memory = %d" % number_of_guests
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msg += "\n - number of guest vCPUs allowed = %d" % int(guest_vcpus)
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msg += "\n - nova.conf cpu_allocation_ratio = %2.2f" % cpu_allocation_ratio
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msg += "\n - nova.conf reserved_host_memory = %d MB" % nova_reserved_mem_mb
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msg += "\n "
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if workload:
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msg += "\nCompare \"guest vCPUs allowed\" to \"guests allowed based on memory\""
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msg += "\nfor actual guest count."
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msg += "\n "
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warning_msg = ""
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if nova_reserved_mem_mb > (MB_PER_GB * mem_gb * total_memory_threshold):
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warning_msg += "ERROR: %d GB is not enough memory to run hyperconverged\n" % mem_gb
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derived['failed'] = True
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if workload:
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if cpu_allocation_ratio < 0.5:
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warning_msg += "ERROR: %d is not enough vCPU to run hyperconverged\n" % vcpus
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derived['failed'] = True
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if cpu_allocation_ratio > 16.0:
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warning_msg += "WARNING: do not increase vCPU overcommit ratio beyond 16:1\n"
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else:
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warning_msg += "WARNING: the average guest workload was not provided. \n"
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warning_msg += "Both average_guest_cpu_utilization_percentage and \n"
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warning_msg += "average_guest_memory_size_in_mb are defaulted to 0. \n"
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warning_msg += "The HCI derived parameter calculation cannot set the \n"
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warning_msg += "Nova cpu_allocation_ratio. The Nova reserved_host_memory_mb \n"
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warning_msg += "will be set based on the number of OSDs but the Nova \n"
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warning_msg += "guest memory overhead will not be taken into account. \n"
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derived['message'] = warning_msg + msg
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return derived
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def count_osds(tripleo_environment_parameters):
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"""
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Counts the requested OSDs in the tripleo_environment_parameters.
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Returns an integer representing the count.
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"""
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total = 0
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try:
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disks_config = tripleo_environment_parameters['CephAnsibleDisksConfig']
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for key in ['devices', 'lvm_volumes']:
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total = total + len(disks_config[key])
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except KeyError:
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pass
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return total
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def count_memory(ironic):
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"""
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Counts the memory found in the ironic introspection data as
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represented by memory_mb. Returns integer of memory in GB.
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"""
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try:
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memory = ironic['data']['memory_mb'] / float(MB_PER_GB)
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except KeyError:
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memory = 0
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return memory
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def convert_range_to_number_list(range_list):
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"""
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Returns list of numbers from descriptive range input list
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E.g. ['12-14', '^13', '17'] is converted to [12, 14, 17]
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Returns string with error message if unable to parse input
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"""
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# borrowed from jpalanis@redhat.com
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num_list = []
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exclude_num_list = []
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try:
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for val in range_list:
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val = val.strip(' ')
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if '^' in val:
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exclude_num_list.append(int(val[1:]))
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elif '-' in val:
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split_list = val.split("-")
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range_min = int(split_list[0])
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range_max = int(split_list[1])
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num_list.extend(range(range_min, (range_max + 1)))
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else:
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num_list.append(int(val))
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except ValueError as exc:
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return "Parse Error: Invalid number in input param 'num_list': %s" % exc
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return [num for num in num_list if num not in exclude_num_list]
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def count_nova_vcpu_pins(module):
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"""
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Returns the number of CPUs defined in NovaVcpuPinSet as set in
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the environment or derived parameters. If multiple NovaVcpuPinSet
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parameters are defined, priority is given to role, then the default
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value for all roles, and then what's in previously derived_parameters
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"""
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tripleo_role_name = module.params['tripleo_role_name']
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tripleo_environment_parameters = module.params['tripleo_environment_parameters']
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derived_parameters = module.params['derived_parameters']
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# NovaVcpuPinSet can be defined in multiple locations, and it's
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# important to select the value in order of precedence:
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# 1) User specified value for this role
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# 2) User specified default value for all roles
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# 3) Value derived by a previous derived parameters playbook run
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#
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# Set an exclusive prioritized possible_location to get the NovaVcpuPinSet
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if tripleo_role_name + 'Parameters' in tripleo_environment_parameters: # 1
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possible_location = tripleo_environment_parameters[tripleo_role_name + 'Parameters']
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elif 'NovaVcpuPinSet' in tripleo_environment_parameters: # 2
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possible_location = tripleo_environment_parameters
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elif tripleo_role_name + 'Parameters' in derived_parameters: # 3
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possible_location = derived_parameters[tripleo_role_name + 'Parameters']
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else: # default the possible_location to an empty dictionary
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possible_location = {}
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if 'NovaVcpuPinSet' in possible_location:
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converted = convert_range_to_number_list(possible_location['NovaVcpuPinSet'])
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if isinstance(converted, str):
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module.fail_json(converted)
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if isinstance(converted, list):
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return len(converted)
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return 0
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def count_vcpus(module):
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# if only look at ironic data if NovaVcpuPinSet is not used
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vcpus = count_nova_vcpu_pins(module)
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if vcpus == 0:
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try:
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vcpus = module.params['introspection_data']['data']['cpus']
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except KeyError:
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vcpus = 0
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return vcpus
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def get_vcpus_per_osd(ironic, tripleo_environment_parameters, num_osds):
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"""
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Dynamically sets the vCPU to OSD ratio based the OSD type to:
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HDD | OSDs per device: 1 | vCPUs per device: 1
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SSD | OSDs per device: 1 | vCPUs per device: 4
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NVMe | OSDs per device: 4 | vCPUs per device: 3
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Gets requested OSD list from tripleo_environment_parameters input
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and looks up the device type in ironic input. Returns the vCPUs
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per OSD, an explanation message, and a boolean warning if settings
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are non-optimal.
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"""
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msg_pre = "OSD type distribution: \n"
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msg = ""
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cpus = 1.0
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nvme_re = re.compile('.*nvme.*')
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type_map = {}
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hdd_count = ssd_count = nvme_count = 0
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warning = False
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try:
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devices = tripleo_environment_parameters['CephAnsibleDisksConfig']['devices']
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except KeyError:
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devices = []
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msg = "No devices defined in CephAnsibleDisksConfig"
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warning = True
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try:
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ironic_disks = ironic['data']['inventory']['disks']
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except KeyError:
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ironic_disks = []
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msg = "No disks found in introspection data inventory"
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warning = True
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if len(devices) != num_osds:
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msg = "Not all OSDs are in the devices list. "
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msg += "Unable to determine hardware type for all OSDs. "
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msg += "This might be because lvm_volumes was used to define some OSDs. "
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warning = True
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elif len(devices) > 0 and len(ironic_disks) > 0:
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disks_config = tripleo_environment_parameters['CephAnsibleDisksConfig']
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for osd_dev in disks_config['devices']:
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for ironic_dev in ironic_disks:
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for key in ('name', 'by_path', 'wwn'):
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if key in ironic_dev:
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if osd_dev == ironic_dev[key]:
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if 'rotational' in ironic_dev:
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if ironic_dev['rotational']:
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type_map[osd_dev] = 'hdd'
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hdd_count += 1
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elif nvme_re.search(osd_dev):
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type_map[osd_dev] = 'nvme'
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nvme_count += 1
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else:
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type_map[osd_dev] = 'ssd'
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ssd_count += 1
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msg = " HDDs %i | Non-NVMe SSDs %i | NVMe SSDs %i \n " % \
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(hdd_count, ssd_count, nvme_count)
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if hdd_count > 0 and ssd_count == 0 and nvme_count == 0:
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cpus = 1 # default
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msg += "vCPU to OSD ratio: %i" % cpus
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elif hdd_count == 0 and ssd_count > 0 and nvme_count == 0:
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cpus = 4
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msg += "vCPU to OSD ratio: %i" % cpus
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elif hdd_count == 0 and ssd_count == 0 and nvme_count > 0:
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# did they set OSDs per device?
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if 'osds_per_device' in disks_config:
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osds_per_device = disks_config['osds_per_device']
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else:
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osds_per_device = 1 # default defined in ceph-ansible
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if osds_per_device == 4:
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# All NVMe OSDs so 12 vCPUs per OSD for optimal IO performance
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cpus = 3
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else:
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cpus = 4 # use standard SSD default
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msg += "\nWarning: osds_per_device not set to 4 "
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msg += "but all OSDs are of type NVMe. \n"
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msg += "Recomentation to improve IO: "
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msg += "set osds_per_device to 4 and re-run \n"
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msg += "so that vCPU to OSD ratio is 3 "
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msg += "for 12 vCPUs per OSD."
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warning = True
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msg += "vCPU to OSD ratio: %i" % cpus
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msg += " (found osds_per_device set to: %i)" % osds_per_device
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elif hdd_count == 0 and ssd_count == 0 and nvme_count == 0:
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cpus = 1 # default
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msg += "vCPU to OSD ratio: %i" % cpus
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msg += "\nWarning: unable to determine OSD types. "
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msg += "Unable to recommend optimal ratio so using default."
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warning = True
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else:
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cpus = 1 # default
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msg += "vCPU to OSD ratio: %i" % cpus
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msg += "\nWarning: Requested OSDs are of mixed type. "
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msg += "Unable to recommend optimal ratio so using default."
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warning = True
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return cpus, msg_pre + msg, warning
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def main():
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"""Main method of Ansible module
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"""
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result = dict(
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changed=False,
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message=''
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)
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module_args = dict(
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tripleo_environment_parameters=dict(type=dict, required=True),
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tripleo_role_name=dict(type=str, required=True),
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introspection_data=dict(type=dict, required=True),
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average_guest_cpu_utilization_percentage=dict(type=int, required=False, default=0),
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average_guest_memory_size_in_mb=dict(type=int, required=False, default=0),
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derived_parameters=dict(type=dict, required=False),
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new_heat_environment_path=dict(type=str, required=False),
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report_path=dict(type=str, required=False),
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)
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module = AnsibleModule(
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argument_spec=module_args,
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supports_check_mode=True
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)
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if module.params['derived_parameters'] is None:
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module.params['derived_parameters'] = {}
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vcpus = count_vcpus(module)
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num_osds = count_osds(module.params['tripleo_environment_parameters'])
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mem_gb = count_memory(module.params['introspection_data'])
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mem_gb_per_osd = 5
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vcpu_ratio, vcpu_ratio_msg, vcpu_warn = get_vcpus_per_osd(
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module.params['introspection_data'],
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module.params['tripleo_environment_parameters'],
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num_osds)
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# Derive HCI parameters
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derivation = derive(mem_gb, vcpus, num_osds,
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module.params['average_guest_memory_size_in_mb'],
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module.params['average_guest_cpu_utilization_percentage'],
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mem_gb_per_osd, vcpu_ratio)
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# directly set failed status and message
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result['failed'] = derivation['failed']
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result['message'] = derivation['message']
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if vcpu_warn:
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result['message'] += "\n" + "Warning: " + vcpu_ratio_msg + "\n"
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else:
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result['message'] += "\n" + vcpu_ratio_msg + "\n"
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# make a copy of the existing derived_parameters (e.g. perhaps from NFV)
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existing_params = module.params['derived_parameters']
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# add HCI derived paramters for Nova scheduler
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if not derivation['failed']:
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role_derivation = {}
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role_derivation['NovaReservedHostMemory'] = derivation['nova_reserved_mem_mb']
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if 'cpu_allocation_ratio' in derivation:
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role_derivation['NovaCPUAllocationRatio'] = derivation['cpu_allocation_ratio']
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role_name_parameters = module.params['tripleo_role_name'] + 'Parameters'
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existing_params[role_name_parameters] = role_derivation
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# write out to file if requested
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if module.params['new_heat_environment_path'] and not module.check_mode:
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output = {}
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output['parameter_defaults'] = existing_params
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with open(module.params['new_heat_environment_path'], 'w') as outfile:
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yaml.safe_dump(output, outfile, default_flow_style=False)
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# because we wrote a file we're making a change on the target system
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result['changed'] = True
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if module.params['report_path'] and not module.check_mode:
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with open(module.params['report_path'], 'w') as outfile:
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outfile.write(result['message'])
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# because we wrote a file we're making a change on the target system
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result['changed'] = True
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# return existing derived parameters with the new HCI parameters too
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result['derived_parameters'] = existing_params
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# Exit and pass the key/value results
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module.exit_json(**result)
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if __name__ == '__main__':
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main()
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