On the JVM the Default and IO dispatchers are backed by fixed-size threadpool? right? according to the java docs of

newFixedThreadPool

it is backed by an unbounded job queue. is that true for our dispatchers, too?

IO has unlimited threads. Default is limited by number of cores you have, and at least 2. Job queued are unbound.

This is all written in the KDoc of each dispatcher, please read it.

yes just wanted to make this clear. the actual problem i have: is there a way to track the size of the queue?

No, there's no such way, but why would you need it?

im trying to figure out whats causing the behavior of the system i am experiencing

Maybe you can access the internals and peek at it using reflection on the JVM

i'd love to set up monitoring for it - maybe i will monitor the aprt that offers the jobs in the first place