Hopper offers primitives for distributed task processing in Haskell, simplifying asynchronous workflows and efficient task scheduling.
pinch-gen is an extra-package in the cabal project. Run
$ cabal exec pinch-gen -- --in hopper-thrift/thrift/hopper.thrift --out hopper-thrift/gen-src --hashable-vec-mod Data.Vector.Instances --module-prefix Hopper.Thrift.
to (re-)generate the Thrift data types.
hopper-distributed comes with an example application. The example application binary can run both scheduler and executor based on the flags you pass to them:
To launch a scheduler on port the (default) port 4000 execute
$ cabal run hopper-distributed
In separate terminal you can then execute
$ cabal run hopper-distributed -- executor
to launch an executor. The executor looks for a running scheduler on localhost:4000. If both are running you should see them working and logging.
If you want to be adventurous, you can run not one but many executors by opening many terminals and run the command to launch executors in them.
Play with terminating executors and scheduler and see what happens.