Adding exception tag to http request metrics

[twh270]

Hi all,

I'm improving our service observability, and would like to capture metrics about specific exceptions so we can dashboard/alert on something like CallSomeServiceException. I know I can use @Timed on a method/class, along with @MeterTag to add custom tags, and it will also report an 'exception' tag.

I can also write a HttpServerMetricsTagsContributor, but the context doesn't seem to know anything about an exception thrown by the endpoint.

I'd like to (1) be able to use the built-in metrics for http_server_requests_seconds and (2) not have to put a @Timed annotation on everything, and (3) be able to (at least) add an exception tag to the metrics handling for http_server_requests_seconds, and ideally, be able to share information from the http handler method to the HttpServerMetricsTagsContributor.

Is this a reasonable thing, or is it common to just @Timed everything? What's a good way to approach this?

[quarkus-bot[bot]]

/cc @ebullient (metrics), @jmartisk (metrics)