[MESOS-9254] Make SLRP be able to update its volumes and storage pools.

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.9.0
• Labels: mesosphere mesosphere-dss-post-ga storage
• Epic Link: Resource Provider and CSI Tech Debt
• Sprint: Storage: RI-16 Sprint 51, Storage: RI-17 Sprint 52
• Story Points: 5
• Assignee: Benjamin Bannier
• Reporter: Chun-Hung Hsiao
• Shepherd: Chun-Hung Hsiao
• Created: 25/Sep/18 00:00
• Updated: 20/Aug/19 10:05
• Resolved: 20/Aug/19 10:05

Description

We should consider making SLRP update its resources periodically, or adding an endpoint to trigger that, for the following reasons:

1. Mesos currently assumes all profiles have disjoint storage pools. This is because Mesos models each resource independently. However, in practice an operator can set up, say two profiles, one for linear volumes and one for raid volumes, and an "LVM" resource provider that can provision both linear and raid volumes. The correlation between the storage pools of the linear and raid profiles would reduce one's pool capacity when a volume of the other type is provisioned. To reflect the actual sizes of correlated storage pools, we need a way to make SLRP update its resources.

2. The SLRP now only queries the CSI plugin to report a list of volumes during startup, so if a new device is added, the operator will have to restart the agent to trigger another SLRP startup, which is inconvenient.

Issue Links

• is blocked by: MESOS-9553 Do not drop operations when SLRP reconciles storage pools.
• relates to: MESOS-9540 Support `DESTROY_DISK` on preprovisioned CSI volumes.
• relates to: MESOS-9004 Add unit tests for dropping operations during SLRP reconciliation.