public void start()

in software/nosql/src/main/java/org/apache/brooklyn/entity/nosql/mongodb/MongoDBReplicaSetImpl.java [344:413]
61 lines of code
10 McCabe index (conditional complexity)

    public void start(Collection<? extends Location> locations) {
        // Promises that all the cluster's members have SERVICE_UP true on returning.
        super.start(locations);
        policy = policies().add(PolicySpec.create(MemberTrackingPolicy.class)
                .displayName(getName() + " membership tracker")
                .configure("group", this));

        for (AttributeSensor<Long> sensor: SENSORS_TO_SUM)
            enrichers().add(Enrichers.builder()
                    .aggregating(sensor)
                    .publishing(sensor)
                    .fromMembers()
                    .computingSum()
                    .valueToReportIfNoSensors(null)
                    .defaultValueForUnreportedSensors(null)
                    .build());
        
        // FIXME would it be simpler to have a *subscription* on four or five sensors on allMembers, including SERVICE_UP
        // (which we currently don't check), rather than an enricher, and call to an "update" method?
        enrichers().add(Enrichers.builder()
                .aggregating(MongoDBServer.REPLICA_SET_PRIMARY_ENDPOINT)
                .publishing(MongoDBServer.REPLICA_SET_PRIMARY_ENDPOINT)
                .fromMembers()
                .valueToReportIfNoSensors(null)
                .computing(new Function<Collection<String>, String>() {
                        @Override
                        public String apply(Collection<String> input) {
                            if (input==null || input.isEmpty()) return null;
                            Set<String> distinct = MutableSet.of();
                            for (String endpoint: input)
                                if (!Strings.isBlank(endpoint))
                                    distinct.add(endpoint);
                            if (distinct.size()>1)
                                LOG.warn("Mongo replica set "+MongoDBReplicaSetImpl.this+" detetcted multiple masters (transitioning?): "+distinct);
                            return input.iterator().next();
                        }})
                .build());

        enrichers().add(Enrichers.builder()
                .aggregating(MongoDBServer.MONGO_SERVER_ENDPOINT)
                .publishing(REPLICA_SET_ENDPOINTS)
                .fromMembers()
                .valueToReportIfNoSensors(null)
                .computing(new Function<Collection<String>, List<String>>() {
                        @Override
                        public List<String> apply(Collection<String> input) {
                            Set<String> endpoints = new TreeSet<String>();
                            for (String endpoint: input) {
                                if (!Strings.isBlank(endpoint)) {
                                    endpoints.add(endpoint);
                                }
                            }
                            return MutableList.copyOf(endpoints);
                        }})
                .build());
        
        enrichers().add(Enrichers.builder()
                .transforming(REPLICA_SET_ENDPOINTS)
                .publishing(DATASTORE_URL)
                .computing(new EndpointsToDatastoreUrlMapper(this))
                .build());

        subscriptions().subscribeToMembers(this, MongoDBServer.IS_PRIMARY_FOR_REPLICA_SET, new SensorEventListener<Boolean>() {
            @Override public void onEvent(SensorEvent<Boolean> event) {
                if (Boolean.TRUE == event.getValue())
                    sensors().set(PRIMARY_ENTITY, (MongoDBServer)event.getSource());
            }
        });

    }