Deprecation of Direct Engine¶
https://blueprints.launchpad.net/sahara/+spec/deprecate-direct-engine
Currently Sahara has two types of infrastructure engines. First is Direct Infrastructure Engine and second is Heat Infrastructure Engine. This spec proposes deprecating the Direct Engine.
Problem description¶
Each time when Sahara start support new feature, Sahara should support it in both engines. So, it became much harder to support both versions of engines, because in case of Direct Engine it would need to have duplication of work, which is already done in Heat.
Proposed change¶
It’s proposed to deprecate Direct Engine in Liberty release, but it will be
available to use. After merging this spec Direct Engine should be freezed
for new feautures which will be added in Liberty. It will be opened for
fixes of High and Critical bugs. We should make Heat Engine used by
default in Sahara.
This change will allow to switch most testing jobs in Sahara CI to use Heat Engine instead of Direct Engine.
In M release we should remove all operations from direct engine. After that the only operation which can be done with direct-engine-created cluster is the cluster deletion. We should rewrite cluster deletion behavior to support deletion direct-engine-created cluster via Heat Engine. Now heat engine removes cluster from database but doesn’t remove all cluster elements (for example, instances).
Alternatives¶
Sahara can continue support of both engines.
Data model impact¶
None
REST API impact¶
None
Other end user impact¶
None
Deployer impact¶
Deployers should switch to use Heat Engine instead of Direct Engine.
Developer impact¶
New features, which impacts infrastructure part of Sahara, should be supported only in Heat Engine.
Sahara-image-elements impact¶
None
Sahara-dashboard / Horizon impact¶
None
Implementation¶
Assignee(s)¶
- Primary assignee:
vgridnev
- Other contributors:
None
Work Items¶
This change will require following changes:
Add deprecation warnings at sahara startup.
Mark Heat Engine as default in Sahara.
Document deprecation of Direct Engine.
Dependencies¶
None
Testing¶
This change require manual testing of deletion direct-engine-created cluster after switch to heat engine.
Documentation Impact¶
Need to document that Direct Engine became deprecated.
References¶
None
