watcher/doc/source/strategies/vm_workload_consolidation.rst
Lucian Petrut 424e9a76af vm workload consolidation: use actual host metrics
The "vm workload consolidation" strategy is summing up instance
usage in order to estimate host usage.

The problem is that some infrastructure services (e.g. OVS or Ceph
clients) may also use a significant amount of resources, which
would be ignored. This can impact Watcher's ability to detect
overloaded nodes and correctly rebalance the workload.

This commit will use the host metrics, if available. The proposed
implementation uses the maximum value between the host metric
and the sum of the instance metrics.

Note that we're holding a dict of host metric deltas in order to
account for planned migrations.

Change-Id: I82f474ee613f6c9a7c0a9d24a05cba41d2f68edb
2023-10-27 21:54:42 +03:00

113 lines
3.4 KiB
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==================================
VM Workload Consolidation Strategy
==================================
Synopsis
--------
**display name**: ``VM Workload Consolidation Strategy``
**goal**: ``vm_consolidation``
.. watcher-term:: watcher.decision_engine.strategy.strategies.vm_workload_consolidation.VMWorkloadConsolidation
Requirements
------------
Metrics
*******
The *vm_workload_consolidation* strategy requires the following metrics:
============================ ============ ======= =========================
metric service name plugins comment
============================ ============ ======= =========================
``cpu`` ceilometer_ none
``memory.resident`` ceilometer_ none
``memory`` ceilometer_ none
``disk.root.size`` ceilometer_ none
``compute.node.cpu.percent`` ceilometer_ none (optional) need to set the
``compute_monitors`` option
to ``cpu.virt_driver`` in the
nova.conf.
``hardware.memory.used`` ceilometer_ SNMP_ (optional)
============================ ============ ======= =========================
.. _ceilometer: https://docs.openstack.org/ceilometer/latest/admin/telemetry-measurements.html#openstack-compute
.. _SNMP: https://docs.openstack.org/ceilometer/latest/admin/telemetry-measurements.html#snmp-based-meters
Cluster data model
******************
Default Watcher's Compute cluster data model:
.. watcher-term:: watcher.decision_engine.model.collector.nova.NovaClusterDataModelCollector
Actions
*******
Default Watcher's actions:
.. list-table::
:widths: 30 30
:header-rows: 1
* - action
- description
* - ``migration``
- .. watcher-term:: watcher.applier.actions.migration.Migrate
* - ``change_nova_service_state``
- .. watcher-term:: watcher.applier.actions.change_nova_service_state.ChangeNovaServiceState
Planner
*******
Default Watcher's planner:
.. watcher-term:: watcher.decision_engine.planner.weight.WeightPlanner
Configuration
-------------
Strategy parameter is:
====================== ====== ============= ===================================
parameter type default Value description
====================== ====== ============= ===================================
``period`` Number 3600 The time interval in seconds
for getting statistic aggregation
from metric data source
====================== ====== ============= ===================================
Efficacy Indicator
------------------
.. watcher-func::
:format: literal_block
watcher.decision_engine.goal.efficacy.specs.ServerConsolidation.get_global_efficacy_indicator
Algorithm
---------
For more information on the VM Workload consolidation strategy please refer to: https://specs.openstack.org/openstack/watcher-specs/specs/mitaka/implemented/zhaw-load-consolidation.html
How to use it ?
---------------
.. code-block:: shell
$ openstack optimize audittemplate create \
at1 server_consolidation --strategy vm_workload_consolidation
$ openstack optimize audit create -a at1
External Links
--------------
*Spec URL*
https://specs.openstack.org/openstack/watcher-specs/specs/mitaka/implemented/zhaw-load-consolidation.html