Monasca High Availability & Monasca-Agent Role


2015-10-07 17:00


Ansible, Monasca, Monasca-agent, High Availability, Clustering

Currently, the Monasca role for Openstack-Ansible does not configure any of the services in HA. Installation of the monasca-agent into hosts and containers is also not handled.

Problem description

Most modern monitoring systems have the ability to cluster its database for resiliency and present the user interface in a highly available fashion. The Monasca role as currently defined only launches single hosts with the supporting services configured as single hosts. If you wanted to put the monasca-api behind a VIP, you would have three different apis with disparate information.

There is currently no monasca-agent Openstack-Ansible role defined. To get monasca-agent on a Openstack-Ansible installation, you have to manually install it, or use the ansible-monasca-agent playbook to install it into hosts and containers after the fact.

Proposed change

Notable changes:
  • Monasca-api & friends

  • The following services must be placed under a VIP

  • Monasca-api

  • Influxdb

  • MySQL

  • The following services must have clustering configured:

  • MySQL

  • Influxdb

  • Storm Nimbus & Supervisor

  • Storm Nimbus & Supervisor

  • Zookeeper

  • Grafana & Monasca-ui

    • Not clustered, but for HA to work correctly on Grafana, session sharing and configuration database connection must be set to the Openstack-Ansible Galera cluster

  • Add python-monascaclient to the utility containers

  • Monasca-agent

  • The os_monasca-agent role must be developed to install the agent onto all hosts during the pre-install

  • Improvements must be made to monasca-agent to correctly identify all services


Only alternative is using another monitoring system if you plan on using Openstack-Ansible, or living with the eventual doom of your monitoring data.

Playbook/Role impact

If the user does not include the os_monasca role, there will be no impact other than the inclusion of the python-monascaclient into the utility containers. If included, the user will likely have to add a few configuration options, like VIP ranges, replication factors, things that related solely to monitoring and data resiliency.

Upgrade impact

Monasca & friends work independently from Openstack-Ansible so no impact to the openstack upgrade process is expected.

If the containers are trashed during the upgrade, monasca-agent will have to be re-installed. If not, monasca-reconfigure script will have to be ran to discover changes to hosts/containers.

Security impact

  • Does this change touch sensitive data such as tokens, keys, or user data?

    • Only sensitive item the playbook would need would be the admin password to enroll the monasca users & endpoints.

  • Does this change alter a deployed OpenStack API in a way that may impact security, such as a new way to access sensitive information or a new way to login?

    • Monasca uses it’s own API and only consumes from the keystone API.

  • Does this change involve cryptography or hashing?

    • No

  • Does this change require the use of sudo or any elevated privileges?

    • Yes but only on the dedicated Monasca hosts to install & configure services. Monasca-agent install does not require escalation.

  • Does this change involve using or parsing user-provided data? This could be directly at the API level or indirectly such as changes to a cache layer.

    • Only Monasca specific variables will be provided by users.

Performance impact

Monasca runs on its own dedicated hosts.

The impact of the monasca-agent on hosts & containers is minimal.

End user impact

Addition of monitoring as a service. No changes to existing user exposed services.

Deployer impact

  • What config options are being added? Should they be more generic than proposed? Are the default values ones which will work well in real deployments?

  • Only configuration options related to Monasca will be added.

  • Is this a change that takes immediate effect after its merged, or is it something that has to be explicitly enabled?

  • Monasca must be explicitly enabled.

  • If this change is a new binary, how would it be deployed?

  • N/A

  • Please state anything that those doing continuous deployment, or those upgrading from the previous release, need to be aware of. Also describe any plans to deprecate configuration values or features. For example, if we change the name of a play, how do we handle deployments before the change landed? Do we have a special case in the code? Do we assume that the operator will recreate containers within the infrastructure of the cloud? Does this effect running instances within the cloud?

  • Does not affect current Openstack Installation without Monasca.

  • Monasca specific upgrade instructions will be provided if needed.

Developer impact

Will not affect developers not working with Monasca.


No blueprint dependencies.



Primary assignee:


Work items

Same as Proposed changes.


The os_monasca role already has testing. I will look at similar roles and determine what best tests to implement for testing the HA aspect of Monasca.

Documentation impact

Openstack-Ansible documentation will not be affected.

New os_monasca documentation will be written.