i'd have thought you could blacklist the jetty namespaces using timbre's configuration https://github.com/ptaoussanis/timbre#configuration
you can blacklist specific namespaces, e.g.
:ns-blacklist ["*jetty.*"]
(or something like that)
you can add that into timbre dynamically with timbre/merge-config!
, something like
(timbre/merge-config! {:ns-blacklist ["*.jetty.*"]})
maybe give that a shot? note that you can actually write your own appender functions to filter messages (or do anything else), so you could drop in a function that says "if it's jetty and doesn't include the word Exception then ignore"