Ussuri Series Release Notes



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

  • 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:

  • 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.