Log errors when fibers exit with an error in ResponseLogger
#7678
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danicheg
commented
May 9, 2025
| object ResponseLogger { | ||
| private[this] val logger = Platform.loggerFactory.getLogger | ||
| private[this] val errorLogger = | ||
| Platform.loggerFactory.getLoggerFromName("org.http4s.server.service-errors") |
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FWIW, we're already instantiating the logger with that name in org.http4s.server, so it should be cached already.
danicheg
commented
May 9, 2025
| )(implicit G: MonadCancelThrow[G], F: Async[F]): Kleisli[G, A, Response[F]] = { | ||
| val fallback: String => F[Unit] = s => logger.info(s).to[F] | ||
| val log = logAction.fold(fallback)(identity) | ||
| val errLog: (String, Throwable) => F[Unit] = (msg, th) => errorLogger.error(th)(msg).to[F] |
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Perhaps a better approach would be to add errLogAction alongside logAction, allowing users to decide how to log that case. But unfortunately, that would require duplicating a bunch of constructors to preserve binary compatibility, which I’m confident would hurt ergonomics for very little gain. Maybe I’ll revisit this in 1.0, but definitely not in 0.23.
rossabaker
approved these changes
Sep 22, 2025
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Today, I was investigating the classic thing when updating dependencies in a service that hasn’t been touched in years, and I was a bit amazed when I found this debug log (kinda cool that it got printed on that running environment though):
... with no additional info, like stack traces or anything meaningful else.
So, I propose to log errors by default for cases fibers exit with an error in
ResponseLogger.