Cloned from launchpad blueprint https://blueprints.launchpad.net/nova/+spec/transaction-manager.

Description:

In Openstack we have a lot of code that is creating/allocating some resources (networks, volumes, quotas, etc.) but we don't have a clear way to release such resources in case of failure. Release is currently done manually in "except" block. Such approach leads to more complicated error handling and potential resource leak.
We could implement a utility that will help us to manage such resources and will allow us to simplify existing error handling and fix resource leak issues.

Please see Specification URL for details

Specification URL (additional information):

https://wiki.openstack.org/wiki/TransactionManager