public void update()

in software/nosql/src/main/java/org/apache/brooklyn/entity/nosql/cassandra/CassandraDatacenterImpl.java [453:488]
30 lines of code
9 McCabe index (conditional complexity)

    public void update() {
        synchronized (mutex) {
            // Update our seeds, as necessary
            seedTracker.refreshSeeds();
            
            // Choose the first available cluster member to set host and port (and compute one-up)
            Optional<Entity> upNode = Iterables.tryFind(getMembers(), EntityPredicates.attributeEqualTo(SERVICE_UP, Boolean.TRUE));

            if (upNode.isPresent()) {
                sensors().set(HOSTNAME, upNode.get().getAttribute(Attributes.HOSTNAME));
                sensors().set(THRIFT_PORT, upNode.get().getAttribute(CassandraNode.THRIFT_PORT));

                List<String> currentNodes = getAttribute(CASSANDRA_CLUSTER_NODES);
                Set<String> oldNodes = (currentNodes != null) ? ImmutableSet.copyOf(currentNodes) : ImmutableSet.<String>of();
                Set<String> newNodes = MutableSet.<String>of();
                for (Entity member : getMembers()) {
                    if (member instanceof CassandraNode && Boolean.TRUE.equals(member.getAttribute(SERVICE_UP))) {
                        String hostname = member.getAttribute(Attributes.HOSTNAME);
                        Integer thriftPort = member.getAttribute(CassandraNode.THRIFT_PORT);
                        if (hostname != null && thriftPort != null) {
                            newNodes.add(HostAndPort.fromParts(hostname, thriftPort).toString());
                        }
                    }
                }
                if (Sets.symmetricDifference(oldNodes, newNodes).size() > 0) {
                    sensors().set(CASSANDRA_CLUSTER_NODES, MutableList.copyOf(newNodes));
                }
            } else {
                sensors().set(HOSTNAME, null);
                sensors().set(THRIFT_PORT, null);
                sensors().set(CASSANDRA_CLUSTER_NODES, Collections.<String>emptyList());
            }

            ServiceNotUpLogic.updateNotUpIndicatorRequiringNonEmptyList(this, CASSANDRA_CLUSTER_NODES);
        }
    }