Is your queue growing because you need more workers

Worker CPU sits near zero, the queue length keeps climbing, and nobody can say whether that means add workers or something else entirely.

Intermediate to advancedRead 7 minDoing: an afternoon8 steps

▶ Start

What you'll have at the end

A worker count and prefetch setting chosen from a measured queue-length graph instead of a guess

Before you start

You need

A background job queue that's visibly growing over time, at least two job types sharing it with noticeably different run times, and access to your broker's own queue-length command plus your worker pool's own inspection command.

Not covered

A queue stuck behind one specific job that keeps failing and retrying forever. That's a poison message, not a capacity or prefetch problem, and it needs a different fix entirely.

Leans on

8 steps

Where to go next

Catch the one poison message that retries forever and starves every worker

go there instead if the inspection command keeps showing the exact same job retrying over and over, rather than a mix of genuinely different long jobs; that's one bad message, not a capacity or prefetch problem.

Checked 19 Aug 2026

Part of the Background Job Processing Systems cookbook