Prefer eliminating work that can’t affect observable behavior and prevent resource retention in hot paths.

Apply this as a checklist: 1) Guard mode-dependent logic: if the subsystem doesn’t propagate updates (or the surrounding condition is false), skip the computation/action entirely.

• Example pattern (prefetch/QoS):

  if worker_enable_prefetch_count_reduction:
      # If per-consumer QoS (apply_global=False), broker qos updates won’t reach running consumers.
      if qos_global is False:
          logger.info("Skipping prefetch reduction; per-consumer QoS in effect")
      else:
          active_count = len(active_requests)  # snapshot once
          initial_prefetch_count = max(
              prefetch_multiplier,
              max_prefetch_count - active_count * prefetch_multiplier,
          )
  

  2) Run expensive checks/copies only when needed: move detect_* calls and copy.copy(...) inside the “schedule changed” condition. 3) Avoid redundant computation drift: snapshot once and reuse (e.g., active_count = len(active_requests)) rather than recomputing in multiple expressions/logs. 4) Use the right data structures for de-duplication: prefer sets for membership/de-dup and convert at the end, avoiding repeated O(n) in list checks. 5) Prevent memory retention in exception/error handling: clear traceback frame references (e.g., traceback_clear(exc)) and delete local traceback variables (del tb) when they are no longer needed. 6) Avoid “harmless” side-effect calls that allocate resources: in pub/sub flows, don’t ping when there are no subscribers or when ping triggers empty replies/extra allocations.

These changes improve throughput and memory usage without altering functional behavior.