returns 500..599.
It is encouraged in the Phoenix docs to use `Plug.Exception` with
custom exceptions to generate for example 404 responses at certain
places. These 404s should not be marked as error, since simple "route
not found" 404s are also not marked as error.
Co-authored-by: Tristan Sloughter <t@crashfast.com>
There is an edge case, if you use `forward/4` and use Plug.ErrorHandler,
then when an exception reaches the outer router, then Plug.send_resp
will be called, triggering `[:phoenix, :endpoint, :stop]`, and the span
will be gone by the time the outer router gets the exception. This
causes this telemetry handler to crash and be detached.
Sequence of events:
- [:phoenix, :endpoint, :start]
- [:phoenix, :router_dispatch, :exception] (inner router)
- [:phoenix, :endpoint, :stop]
- [:phoenix, :router_dispatch, :exception] (outer router) ** here there is no span, crashes
Derek Kraan
Bryan Naegele
Yordis Prieto
matthijsqd
Ho-Yon Mak
Seth Archer Brown