Ussuri Series Release Notes

4.0.0

Prelude

Many operations in the decision engine will block on I/O. Such I/O operations can stall the execution of a sequential application significantly. To reduce the potential bottleneck of many operations the general purpose decision engine threadpool is introduced.

New Features

• Add a new webhook API and a new audit type EVENT, the microversion is 1.4. Now Watcher user can create audit with EVENT type and the audit will be triggered by webhook API. The user guide is available online: https://docs.openstack.org/watcher/latest/user/event_type_audit.html

• A new threadpool for the decision engine that contributors can use to improve the performance of many operations, primarily I/O bound onces. The amount of workers used by the decision engine threadpool can be configured to scale according to the available infrastructure using the watcher_decision_engine.max_general_workers config option. Documentation for contributors to effectively use this threadpool is available online: https://docs.openstack.org/watcher/latest/contributor/concurrency.html

• The building of the compute (Nova) data model will be done using the decision engine threadpool, thereby, significantly reducing the total time required to build it.

Upgrade Notes

• Python 2.7 support has been dropped. Last release of Watcher to support py2.7 is OpenStack Train. The minimum version of Python now supported by Watcher is Python 3.6.