Eventually Consistent DHCP Agent
The DHCP agent has a number of design flaws in its state synchronization strategy that have the potential to negatively impact reliability. Notifications may be processed in the wrong order, there is no way to detect whether a notification is stale, and there is no guarantee that missed notifications will be detected. Any of these may result in inconsistencies between db and agent-local state that could impact VM connectivity. Explicit notification ordering should be possible and the agent should use this ordering to ensure eventual consistency.
Blueprint information
- Status:
- Complete
- Approver:
- Mark McClain
- Priority:
- High
- Drafter:
- Maru Newby
- Direction:
- Needs approval
- Assignee:
- None
- Definition:
- Obsolete
- Series goal:
- None
- Implementation:
-
Deferred
- Milestone target:
- None
- Started by
- Completed by
- Armando Migliaccio
Related branches
Related bugs
Sprints
Whiteboard
Nov-20-2015(armax): If someone is interested in pursuing it, this must be re-submitted according to guidelines defined in [1].
[1] http://
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As per feedback from a number of people at the Tempest/Neutron sprint in Montreal, the proposal to guarantee notification ordering via a per-network sequence id is considered too complicated to pursue in the icehouse timeframe. A potential stop-gap is to stop consuming notification payloads and use the delivery of a notification only as an indication that a change has occurred that requires making a request to the server.
