Class: Greenroom::Census::Middleware

Inherits:
Object
  • Object
show all
Defined in:
lib/greenroom/census/middleware.rb

Overview

A Sidekiq server middleware that closes the one gap Census::Job cannot close on its own: when each_iteration raises, Sidekiq re-raises out of perform without calling on_stop, so the thread-local recorder build_enumerator installed is never uninstalled. Sidekiq reuses worker threads across jobs, so without this middleware, the next unrelated job Sidekiq happens to run on that thread would find an experiment already turned on -- the one safety property this gem promises (a candidate runs only inside a census) would be broken by an ordinary job failure.

Census::Job#build_enumerator also uninstalls at its own start, as a second, narrower guard between one census job and the next -- but that only covers census jobs calling each other; it cannot help an unrelated job. A host must add this middleware to its Sidekiq server middleware chain for the guarantee to hold in general.

Instance Method Summary collapse

Instance Method Details

#call(_job_instance, _job_payload, _queue) ⇒ Object 



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# File 'lib/greenroom/census/middleware.rb', line 23

def call(_job_instance, _job_payload, _queue)
  yield
ensure
  Greenroom::Recorder.uninstall
end