Known gaps · metrics4s · Sendline Open Source

Known gaps

process_resident_memory_bytes is read from /proc, so it exists only on Linux. On macOS that JVM panel is empty.
MongoDB command series are not created up front: commands times collections times buckets would be thousands of zeros. Their panels fill as the commands run.
rapid cancels by interrupting a thread. A fiber cancelled while parked on a callback runs none of its finalizers.
Kyo does not wait for a cancelled fiber's finalizers, so they may finish after the cancellation returns.
ZIO fiber metrics count only the fibers started after the metrics are registered.
cats-effect 3.7.1 counts a timer that fires on its own thread twice in _executed, and _canceled lags behind.
metrics4s_callback_errors_total is read in the same scrape as the callbacks it counts, so a scrape shows the failures up to the one before it.