notification about entities that are back to live

[pchainho]

As discussed here

[rjflp]

One possible way to do this, maintaining the REST interface:

To request notification

• Runtime asks for notification
• Connector transmits the request to the Domain Registry server (REST call)
• DR server appends the URL to notify to the notification list of the object to observe

When there is a change:

• The reply to REST (PUT) calls will return the list of URL (message destinations) to notify. The DR clears the list of URLs to notify.
• The connector pushs the messages into the Message Node

[rjflp]

Status update: -Methods mostly implemented in the Domain Registry. Still missing database storage. -Connector still Work In Progress -Runtime still WIP

[rjflp]

@pchainho When the runtime receives the notification, from the message node, that the hyperty is back, what should happen?

[nunofmn]

@pchainho, what do need to implement here from the connector side? The specs only define a message to the Message Node Subscription Manager.

[pchainho]

As far as I remember, the connector only has to publish status changes:

• When registered entities goes offline publish change to disconnected
• When registered entities goes online publish change to live

[nunofmn]

But there is this message also: https://github.com/reTHINK-project/specs/blob/master/messages/registration-messages.md#subscribe-to-receive-notifications-about-registration-status-changes

Is the Subscription Manager that contacts the Domain Registry directly?

[pchainho]

No, it is the MN that broadcasts the published status change to all subscribers using pub—sub

[nunofmn]

In order to this to work is still necessary to implement the "notification" functionality in the Runtime side. Our proposal of API that should be exposed by the Service Framework is simple:

• subscribe(<URL_to_subscribe>, <subscriber>, callback)
• unsubscribe(<URL_to_unsubscribe>, <subscriber>)

From the Runtime <-> Subscription Manager comunication, this will have the following interactions:

• When the subscribe function is called a message is sent from the Runtime to the Subscription Manager (detailed here).
• When a status change is detected the SM will send a message to the Runtimes that asked to be notified. The Runtime then propagates the notification to all the "entities" that subscribed for the change using the subscribe function by calling the associated callbacks.

@pchainho seems ok?

[pchainho]

As discussed in Slack I would propose a more developer friendly API in the service framework discovery lib, where each returned discovered object will support a onLive() and a onDisconnect() event handler.

[BernardoMG]

This issue is complete.

The changes are in branch: hyperty-notification (service-framework); disconnected-hyperties (runtime-core); connector-release-1.0.0 (msg-node-vertx); 32-connector-sm (registry-domain).

This issue will be closed after the next release.

[BernardoMG]

We are replicating the notifications feature to data objects.

[BernardoMG]

Notification feature is now available not only for hyperties but also for data objects.

The changes are in branch: hyperty-notification (service-framework); disconnected-hyperties (runtime-core); connector-release-1.0.0 (msg-node-vertx); 32-connector-sm (registry-domain).

This issue will be closed after the next release.

[pchainho]

I've found some issues when testing with UserAvailability Hyperties at hyperty-notification branch from dev-hyperty repo:

1. when unregistering HypertyAvailabilityReporter, executing runtime.registry.unregisterAllHyperties(); in the browser console I receive a "not found" response:

then, if from HypertyAvailabilityObserver side I try to discover this Hyperty, I got results with "status = live":

2. when the expires is set to 30 sec in the UserAvailabilityReporter Hyperty configuration, and after the UserAvailabilityObserver subscribes the reporter, if I close the windows browser without explicitely unregistering the hyperty (ie sending an update message with status = disconnected), the UserAvailabilityObserver does not receive the onDisconnect event when the Hyperty registration expires (after 30 secs)

[BernardoMG]

Hi @pchainho .

1. The resource field is wrong. Should be only: hyperty://localhost/cc5a34be-d08b-4ff6-a21b-7859690b85b5.

2. And that is correct, according to the implementation. The HeartBeatThread runs only after one hour. So, unless you make a GET request for the hyperty that validates the expire field, you should wait for the HeartBeatThread.

[BernardoMG]

This issue should be fixed in later versions.

Closing for now.