MD-SAL and Context Memory Integration

Table of Contents

1 Introduction
2 Current Design
3 Sample Code
4 NodeString Format

Introduction

The controller using OpenDayLight and SLI need to integrated MD-SAL and context memory. This page will provide some sample code and design details.

If you are not interested in the provider code or design, but work on directed graphs you can skip to NodeString Format (fill in link).

Current Design

Yang model is created by hand or using a tool.
YangTools (ODL project) generates java classes from the YangModel.
MdsalHelper (ATT code) can convert the generated java object to and from context memory format.

Today the binding aware broker is being used. The DOM data broker is not supported currently. Below is a detailed diagram of the overall flow.

Sample Code

MdsalHelper has a method accepting the generated builder class and the properties object. The provider code should populate the properties object before invoking the directed graph.

This is how all of the data setup is done for context memory. For example if we have an RPC and we want everything on the input loaded into context memory we would have the below lines

    @Override
    protected ProvideCustomerVnfNamesRequestOutput execute(ProvideCustomerVnfNamesRequestInput input) throws BusinessObjectException {
        ProvideCustomerVnfNamesRequestOutputBuilder b = new ProvideCustomerVnfNamesRequestOutputBuilder();
        Properties properties = new Properties();
        ProvideCustomerVnfNamesRequestInputBuilder builder = new ProvideCustomerVnfNamesRequestInputBuilder(input);
        MdsalHelper.toProperties(properties, builder);
        return null;
    }

The signature of this method is determined by the generated interface BAREUCPEAPIService. The next steps to make this code work would be to execute the graph with this properties object.

If the RPC needs to read from the config or operational tree you must retrieve the appropriate builder object and load it into the same properties object. The below block of code can be used to get the builder for config or operational based on the service instance id.

    protected ServiceDataBuilder getData(InstanceIdentifier<ServiceList> id, LogicalDatastoreType type) {
        String siid = id.toString();
        Optional<ServiceList> data = null;
        try {
            ReadOnlyTransaction readTx = getDataBroker().newReadOnlyTransaction();
            data = readTx.read(type, id).get();
        } catch (InterruptedException | ExecutionException e) {
            log.error("Caught Exception reading MD-SAL (" + type + ") for [" + siid + "] ", e);
        }
        log.debug("data:" + data);
        if (data.isPresent()) {
            ServiceData serviceData = (ServiceData) data.get().getServiceData();
            ServiceDataBuilder serviceDataBuilder = new ServiceDataBuilder(serviceData);

            if (serviceData != null) {
                log.info("Read MD-SAL (" + type + ") data for [" + siid + "] ServiceData: " + serviceData);
                return serviceDataBuilder;

            } else {
                log.info("No service-data found in MD-SAL (" + type + ") for [" + siid + "] ");
            }
        } else {
            log.info("No data found in MD-SAL (" + type + ") for [" + siid + "] ");
        }
        return null;
    }

This identifier can be built from a string coming in on the RPC a sample method is below

    protected InstanceIdentifier<ServiceList> getInstanceIdentifier(String serviceInstanceId) {
        return InstanceIdentifier.<Services> builder(Services.class).child(ServiceList.class, new ServiceListKey(serviceInstanceId)).toInstance();
    }

To execute the graph we get an instance of SvcLogicService

Then execute is called on this instance. The provider code is responsible for mapping YANG RPCs to Directed Graphs.

The properties object created previously that has been populated with input, config and operational data should be passed in here.

After execution the graph has modified the properties object. This object can be changed back into a builder and the builder can be used to update MD-SAL config or operational.

This object could then be passed into

An example of this call would look like

NodeString Format

See NodeString Format.