RE: [tosca] Event Interface Proposal

Calin,

Thanks for responding. Clarifications below:

1. I am actually referring to cases where artifacts associated with a node template could invoke the event interfaces, consider examples of scripts that could notify the Orchestrator upon some occurrence of some events. In such cases, there should be a way to describe this artifact within the scope of node template.

2. Regarding TOPOLOGY keyword, in the current TOSCA Simple profile specification there are two cases how attribute is assigned a value from operation:

a. Attribute - by means of get_operation_ouput function in attribute definition/assignment

b. Operation â by means of output section

Topology attributes can be filled through substitution mapping. We could adhere to a common approach and provide possibility to fill topology attributes through operation (or event) and read topology attribute values from node instances inside topology.

Let me know your views.

Regards,

Priya

From: tosca@lists.oasis-open.org [mailto:tosca@lists.oasis-open.org] On Behalf Of Calin Curescu
Sent: Wednesday, August 29, 2018 7:59 PM
To: Priya T G; lauwers@ubicity.com
Cc: tosca@lists.oasis-open.org
Subject: Re: [tosca] Event Interface Proposal

Hi Priya,

I realized I have not answered to your mail, I was hoping to discuss it all in the WG meeting before we go further. Anyway, some first thoughts on your proposals inline.

BR,

/Calin

From: <tosca@lists.oasis-open.org> on behalf of Priya T G <priya.g@netcracker.com>
Date: Tuesday, 7 August 2018 at 15:10
To: "lauwers@ubicity.com" <lauwers@ubicity.com>, Calin Curescu <calin.curescu@ericsson.com>
Cc: "tosca@lists.oasis-open.org" <tosca@lists.oasis-open.org>
Subject: [tosca] Event Interface Proposal

Hello Calin, Chris,

This is regarding the event interface proposal that was uploaded in OASIS portal recently: https://www.oasis-open.org/apps/org/workgroup/tosca/download.php/63289/EventInterface2018_06_20.docx

I believe this has not yet been discussed in TOSCA Simple Profile meetings, but is in plan for TOSCA YAML v1.3.

I have a few comments and suggestions on this:

We could embed implementation artifacts in the event_interfaces which could be responsible for triggering these events external to the Orchestrator. This is in addition to how information in such notification will be stored on node instances/topology instance attributes after it has been received.

I was thinking initially that the orchestrator will provide a couple of standard interface technologies (HTTP/REST, RPC, â) to accept these notifications, where the data model exchanged is YAML/JSON. So an external implementation would know exactly how to format data and use the API.

The only effect in the orchestrator is that attributes values are updated and specific orchestrator events are generated. The events may then trigger workflows are already defined in TOSCA, and these workflows can then call operations that artifact implementations can be attached to. If we want to have a shortcut for the latter step (i.e. not needing to set up and specify an entire workflow), Iâm more inclined that we provide an extra âcall_operationâ keyword in the definition that will call a specific operation i.e:

fault_report:

outputs:

name: fault

value: [ SELF, monitor, failure ]

event_types:

- failure_processing

call_operation: #new

- SELF.alarm_processing #new

Just an alignment with common approaches like REST (when you can POST or wait for callback notification), we could rename âevent_interfaceâ as ânotificationâ

Notification is a good alternative. Letâs propose it to the group.

Introduce a new keyword âTOPOLOGYâ on similar lines as âSELFâ. This provides possibility to fill topology attributes as a result of an operation or event and provide possibility to read topology attribute values from node instances inside topology.

I donât think I understand the TOPOLOGY reference. Afaik, there are no attributes that are connected to the topology_template.

BR,

/Calin

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