From: Arun Arora (c) [mailto:[email protected]]
Sent: Thursday, July 06, 2017 10:21 AM
To: Arun Arora (c) <[email protected]>; FREEMAN, BRIAN D <[email protected]>
Cc: [email protected]
Subject: RE: SDN-C Code flow Queries
Hi Brian,
We continued to study the code with the information you provided along with
getting more familiar with the ODL framework. As you explained and we
understood, SDNC has 3 workflows, namely, design-time, onboarding and run-time.
We are trying to understand the code execution flow for each from northbound to
southbound.
We have some questions and would really appreciate if you can provide your
comments on them and if possible provide the APIs for the workflows:
1. Design-Time
* We understand dgbuilder is used to create the directed-graphs. Are
these static files which are stored once created into any database, like AAI?
>> they are static and versioned and stored in the mysql databse in the
>> SVC_LOGIC table.
* Also, what is the input to dgbuilder create the directed-graphs? We
saw in the netconf mount example, that certain JSON are used.. is similar input
used for creating directed graphs for any service/ resource?
>> I dont understand the question. DG creation is a design time activity by the
>> network engineers/developers to implement the state changes. They are not
>> automtically generated.
* What is the role of admin portal in design time
>> its a way to activate new versions of a DG for testing in the development
>> labs. Its also used for add-on admin functions if we need a GUI for some
>> tier support function on an instance but generally its an extremely thin
>> helper application for managing data in the controller.
1. Run-Time
* I have some confusion about the RPC request. I suppose the RPC request
comes to the SDN-C interface as part of the run-time workflow? If yes, what is
the interface on which the RPC request is received?
>> http://[ipaddrss]:8282/restconf/operations/VNF-API:vnf-topology-operation
(POST body would be the json or xml for the input)
You can see the list of these operations in the apidoc/explorer if you have a
running SDNC instnace (btw this is swagger.json based online documenation as
you can see from the GUI view )
* Also, how the directed-graph is used along with RPC input to create
the complete sequence
>> Again not sure I fully understand the question but look at the
>> [sdnc/northbound.git]<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;hb=HEAD>
>> /
>> vnfapi<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi;hb=HEAD>
>> /
>> provider<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider;hb=HEAD>
>> /
>> src<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src;hb=HEAD>
>> /
>> main<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main;hb=HEAD>
>> /
>> java<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main/java;hb=HEAD>
>> /
>> org<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main/java/org;hb=HEAD>
>> /
>> openecomp<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main/java/org/openecomp;hb=HEAD>
>> /
>> sdnc<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main/java/org/openecomp/sdnc;hb=HEAD>
>> /
>> vnfapi<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=tree;f=vnfapi/provider/src/main/java/org/openecomp/sdnc/vnfapi;hb=HEAD>
>> /
@Override
1008<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=blob;f=vnfapi/provider/src/main/java/org/openecomp/sdnc/vnfapi/vnfapiProvider.java;h=92ba08d07c4faa701ef8e588a9f91347dafe3ae5;hb=HEAD#l1008>
public Future<RpcResult<VnfInstanceTopologyOperationOutput>>
vnfInstanceTopologyOperation(
1009<https://gerrit.onap.org/r/gitweb?p=sdnc/northbound.git;a=blob;f=vnfapi/provider/src/main/java/org/openecomp/sdnc/vnfapi/vnfapiProvider.java;h=92ba08d07c4faa701ef8e588a9f91347dafe3ae5;hb=HEAD#l1009>
VnfInstanceTopologyOperationInput input) {
That method maps the vnf-topology-operation (VnfInstanceTopologyOpreration) to
the process of pulling data from md-sal, combining with the input parameters ,
finding the active DG and then calling the execute method on the DG.
From:
[email protected]<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Arun Arora (c)
Sent: Thursday, July 06, 2017 12:38 AM
To: [email protected]<mailto:[email protected]>
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [onap-discuss] SDN-C Code flow Queries
Hi Brian,
Really appreciate this detailed walk through. It would surely help in
expediting our code understanding.
With Best Regards,
Arun Arora
PS: Would ping back if any more queries. Thanks
On Jul 6, 2017, at 12:20 AM, "FREEMAN, BRIAN D"
<[email protected]<mailto:[email protected]>> wrote:
Some replies inline.
Brian
From:
[email protected]<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Arun Arora (c)
Sent: Wednesday, July 05, 2017 10:14 AM
To: [email protected]<mailto:[email protected]>
Subject: [onap-discuss] SDN-C Code flow Queries
Hi There,
We are trying to understand the SDN-C code flow from its Northbound interface
to Southbound Controllers which manage the controlled devices.
Following is our understanding till now (build from ONAP Wiki and code reading):
1) SDN-C is based on ODL framework
>> yes
2) ONAP has added SLI which understands the network configuration workflow
>> yes
3) The DG builder builds different models (using YANG, XML). These models
are then converted into SVC Recopies [Recipies]
>> not quite. DG Builder builds the logic for processing rpc requests that are
>> in yang models. 1 rpc == 1 DG
>> 1 DG can call other DGs as needed to keep the size of any
single DG manageable and to create re-useable DGs
4) SLI consumes into SVC Recopies to execute the network configuration
workflow contained in the recipe
>> yes the RPC in the yang model is a service recipe – the “input” data is the
>> minimum data set needed for the service.
>> the directed graph would then execute to fill out the rest of the containers
>> in the model in the right sequence including assigning resources and
>> calculating attributs as needed. Finally the DG at the ends of the branches
>> would convert/map network data to the device specific attributes in config
>> nodes.
5) Effectively the workflow is passed to one of he underlying Network
Adaptors which actually configure the necessary network resources
>> I hesitate to call it a workflow – it is procedural logic meant to run to
>> complete quickly and deal with devices not people and uses in some cases
>> network signaling protocols like BGP
>> it is the adapters that do the real work of “safe changes in state” of the
>> network which includes things like applying engineering rules to the
>> resource assignments and calculated network attributes (think calculating
>> static routes from newly assigned ip addresses for example)
6) The update (success/ failure) is sent to MSO and AAI once the request
is complete
>> yes. Although the response is to MSO. AAI is updated on success or failure
>> as appropriate. SDNC is the source of truth for network data in AAI that is
>> set/configured/assingned by SDNC.
Following are the code modules we know till now:
1) From MSO mso-sdn-adaptor calls VNFAPIProvider() in SDNCAdpaterRest.java
2) VNFApiProvider() – receives the request and invokes the
activate/configure services
>> the VNFApiProvider is the simplest case of MSO-SDNC interaction and really
>> is used for dealing with L4-L7 VNFs that have a need for resource assignment
>> but not any controller configuration.
Questions:
1. We have seen multiple entry pointers across SDN-C/SLI, dmaplisterner,
uebClient, admportal and dgbuilder. But the interaction of these with each
other, VnfAPIProvider() and southbound interfaces is not clear
>> you need to separate design time / onboarding vs run time.
>> dgbuilder is used as design time to create directed graphs. It is not used
>> during run time. In fact we dont deploy it in production SDNC instnaces we
>> use the desktop version and check the json strings into git.
>> admin portal is only used to load/modify directed graphs and interact with
>> mysql at design time if needed.
>> uebclient is deprecated and it will go away – it was replaced with the
>> dmapplistener
>> dmaaplistener is used during onboarding when new models are distributed from
>> SDNC
>> SDNC/SLI is the run time component that is called when a REST RPC request is
>> sent into the controller. A provider class is called by the rpc and this in
>> turn pulls the xml form of the directed graph from mysql and calls the
>> “execute” function othe SvcLogic object.
2) Post, VnfAPIProvider() how the allocateResourceL3SDN()and later the
Southbound Adpator APIs are called is not known
>> SDNC is nto demonstrating them in this release. The southbound
adapter of interest in SDNC is probably the aai adapter. You can see how the DG
updates AAI in the activate and delete sub-direcged graphs
>> I would also point you to the tutorial on the wiki on the
creating a netconf mount on APPC from SDNC’s VNF API DG.
While we are trying to understand the code further, if anyone can give some
pointers or explain the codeflow on a broader level, it would be extremely
helpful.
Thanks,
Arun Arora
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