EZRA usage examples

Runnable examples that show EZRA in action. Each directory starts a full stack with Docker Compose: an EZRA server, a producer that pushes tasks, and one or more workers that process them.

• python/ — redis-py ≥5.0, RESP3
• node/ — node-redis v4, RESP3

Quick start

Prerequisite: Docker with Compose v2 (docker compose version).

# pick an example
cd python   # or: cd node

# start EZRA, push tasks, and run a worker - all in one
docker compose up --build

The producer runs once and exits. The worker processes tasks as they arrive, then idles out after 30 s with no new work.

To push another batch without restarting everything:

docker compose run --rm producer

Scale workers

docker compose up --build --scale worker=3

Run the producer again. Three workers compete for tasks - each task goes to exactly one worker. The hostname prefix in the logs shows who processed what.

What the demo does

The producer pushes 50 tasks. Each task has a simulated duration (0.1-10 s, log-uniform) so most finish quickly but a few take longer. About 3% of tasks are marked will_fail, which causes the worker to nack them. After max_attempts (default 3) the task lands in the dead-letter queue.

Environment variables

variable	default	effect
TASK_COUNT	50	number of tasks the producer pushes
NACK_MODE	immediate	immediate - xdel, task retries right away; deferred - skip nack, EZRA reclaims after visibility_timeout seconds
IDLE_TIMEOUT	30	seconds a worker waits with no tasks before exiting
EZRA_QUEUE	tasks	queue name

Pass them inline or set in a .env file before starting:

TASK_COUNT=200 docker compose up --build

Links

• EZRA repository
• Full usage reference