darkmarmot
How to kill a Task in Task.Supervisor.async_stream_nolink?
I’m running batches of short-lived fire and forget tasks (I sometimes receive feedback from them).
I can kill the tasks from within themselves… but was hoping to use the supervisor to kill long-running
tasks for me?
I’ve tried variants of the commented options, but have yet to find a way to get them to actually timeout and die . 
Am I missing some basic setting or concept here?
def work(some_values) do
Task.Supervisor.async_stream_nolink(
MyApp.TaskSupervisor,
some_values,
fn v -> do_something(v) end,
ordered: false,
# timeout: 50
# shutdown: 50,
# on_timeout: :kill_task
)
end
Thanks,
Scott
Marked As Solved
darkmarmot
It turned out that an underlying library was trapping exits on spawned processes. So – these processes did end – but produced orphaned processes that made it look non-functional
Also Liked
OvermindDL1
What library was this and what purpose was that for I’m curious?
darkmarmot
So, it was an odd combo.
I’m working with :luerl – and in particular the :luerl_sandbox module which lets you limit the number of reductions used by a process running Lua code.
I had inadvertently been testing without passing in the reductions limit, which defaults to infinite reductions. But I suspect that if you do that it was trapping the exit? (I’m not yet up on Erlang )
When I switched to “normal” :luerl it seemed to work ok. Again, this is more theory than understanding…
OvermindDL1
luerl_sandbox sounds quite useful, right now I run user lua code in a new process and if it does not complete within 5 seconds then I kill it and tell the user their script took too long. I’d love a way to suspend, serialize it out, back in, and resume it though!
darkmarmot
Ohhh that’s a really cool idea! I’ll bring that up on the Luerl Slack if you like!
Another feature I’d appreciate is having it return the reduction count that was used by a script – so it would be easy to see how heavily your script is taxing the cpu.
If you want, check out https://hex.pm/packages/sandbox. It’s my attempt to wrap :luerl_sandbox (still very much in progress though).
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Develop your skills with books, videos, and courses.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Practical resources that improve the lives of professional developers.
Develop your skills with books, videos, and courses.
Producing high quality Elixir screencasts since 2017.
Courses that'll move you from confusion to "Aha, now I get it!"