Get Druid Service details in runtime (via extension)

[Jeet Patel]

Hi all,

Is there a way to to know what druid services are running in a DruidNode (Not
talking about the HTTP APIs)?
I went through druid-server module, class
DruidNodeDiscoveryProvider.getForNodeRole which accepts a NodeRole and
returns a DruidNodeDiscovery instance after which we can use
getAllNodes() method
which returns Collection<DiscoveryDruidNode>. And for each item in the
Collection<DiscoveryDruidNode> we can use getServiceName() method to get
the service name.

The question is, how can we get the instance of NodeRole running in the
druid process. For example, if we have a host running broker service, is
there a way to get NodeRole for broker process dynamically?

For now I'm doing something like this. Adding all NodeRole in every host,
since our extension runs in every host.:

List<DruidNodeDiscovery> druidNodeDiscoveryList = ImmutableList.of(
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.COORDINATOR),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.OVERLORD),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.HISTORICAL),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.MIDDLE_MANAGER),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.INDEXER),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.BROKER),
        druidNodeDiscoveryProvider.getForNodeRole(NodeRole.ROUTER)
);

I'm trying to build an extension. So this extension will run in every hosts
in our druid cluster. After getting the service details we wanted to some
further procession from our side.

Will really appreciate some pointers on this.

Thank you :)