CM Handle Connectivity Freshness/Staleness

Related Jira(s):

CPS-1415 - Getting issue details... STATUS

Description

1. Define scenarios which cause a CM Handle to go stale
2. Implement changes to support tracking of CM Handle Freshness/Staleness

What might trigger a cmhandle to go to STALE?

1. dmi plugin identifies that the device is no longer contactable
2. dmi plugin identifies that an underlying device manager managing the device (node) is out of sync with the device itself. 

Scope

1. Currently only supporting NONE and COMPLETE. PARTIAL and POOR may be added later as below.

Changes to DMI Registry Model

We will not be making changes to the DMI Registry Model, Public Properties of the CMHandle will be used where needed.

Triggers of CMHandle trust level change

DMI Availability

Ping every 30 seconds configurable or (every communication with DMI OOS)

Health check endpoint already exists 

http://'$1'/manage/health/readiness

Hazelcast Map

When DMI comes back up, DMI does audit and provides list of Trustworthy CM Handles

Audit triggered by NCMP with list of CMHandles IDs and for DMI to reregister HTTP

Deltas: DMI handling, properties; Delete all under a DMI? Performance?

Device Heart Beat

Assumed functionality is that this will be defined by the DMI Plugin as NCMP does not communicate with device directly

Interface in NCMP for DMI Plugin to be able to tell when device HB has been lost?

10 minute limit should be configurable with 10 as default.

Probably event based

Reregistration

This process occurs when the DMI Plugin Availability is down and then comes back up.
NCMP makes a synchronous call to the DMI Plugin (New Audit Endpoint) to trigger a reregistration
DMI Plugin then reregisters its CMHandles with NCMP (new reregistaration Endpoint?)
NCMP then compares the CMHandles which are being reregistered with the CMHandles which already exist.
CMHandles which are in NCMP but not in DMI reregistration request are kept as trust level none
What happens if there is conflict between the old and new properties of a CMHandle, just take the new properties?
New CMHandles could be registered

Hazelcast for Trust Level

Map Trust level for DMI Plugins
Key: Dmi Name, Values: health check url, trust level

Set Trust level for untrustworthy CMHandles
Key: CmHandleId

When checking the trust level for a CMHandle first check the trust level of that CMHandle's DMI Plugin
If None return None
If Complete check trust level for the CMHandle and return that

Last Data Update

OUT OF SCOPE

Trust Level defined by Client's use of NCMP endpoints to change data related to a CMHandle (passthrough only).

10 minute limit should be configurable with 10 as default.

Stored in public properties

Open Question: External Notifications NCMP is subscribed to should effect this?

Schema Model Mismatch

OUT OF SCOPE

Occurs when data change has been called for a CMHandle and the data change does not fit the defined schema for that CMHandle Anchor (passthrough only).

If this error occurs Trust Level is set to NONE. 

Open Questions