[Hawkular-dev] embedding hawkular-metrics

[John Sanda]

> On Jan 21, 2015, at 4:52 AM, Heiko W.Rupp <hrupp at redhat.com> wrote:
> 
> 
>> Am 21.01.2015 um 05:17 schrieb John Sanda <jsanda at redhat.com>:
>> 
>> One option could be undertow core + json parser. I have not investigated enough to know what if any functionality we get/use from JAX-RS that we might need to implement on our own. We would need a JSON parser.
> 
> WildFly has afaik Jackson as mapper in its list of modules.

I do not see it in WF Core 8.2.0.Final. I have not checked more recent versions WF Core though.

> 
>> 
>> Another option could be netty + json parser. As with undertow, there may be some functionality we currently get/use from JAX-RS that we might need to implement on our own. One potential advantage of netty over undertow is the support for additional protocols. 
> 
> So we pull in (yet another version of) netty into WIldFly to workaround its existing Undertow http thingy?

The issue here is not trying to work around undertow. The issue is that hawkular-metrics currently requires more than  WF Core to be embedded in WF. If I understand correctly, it would be find if our solution requires dependencies X, Z provided they remain implementation details and can be packaged up as a module because then it WF Core would just require that additional module instead as opposed to more WF services. With that said, it will be easier to embed in general with fewer dependencies.

With respect to netty, we already require it for the Cassandra driver. I think it would make sense for metrics and the driver to use the same version. Then we are not pulling in yet another version.

> 
>> The Cassandra driver is also built on netty.
>> 
>> The last option I have thought about is vert.x 3.0. It looks like the minimum/core runtime dependencies are netty, jackson, log4j, and slf4j. This is pretty slim as well. It gives us higher level APIs  and support for implementing REST endpoints. We also have support for additional protocols since this is built on netty.
>