Concurrency

Cap simultaneously-running jobs per task or per queue.

maxConcurrent limits how many jobs of a task run at once across all workers — enforced by the scheduler against the live running count, so it holds even with many workers on shared storage.

queue.task("transcode", transcode, { maxConcurrent: 2 }); // never more than 2 at once

Over the limit, additional jobs stay pending and dispatch as running ones finish.

Apply it to a whole queue:

queue.configureQueue("video", { maxConcurrent: 4 });

Concurrency bounds simultaneous executions; rate limiting bounds throughput over time. They compose — a task can be both maxConcurrent: 2 and 100/min.

Coming from BullMQ? See the note on workers — BullMQ's concurrency option scales with worker-process count; flexiq's maxConcurrent is a single global cap the scheduler enforces no matter how many workers are running.