Engineering / Open resources
Queue, retries and recovery
Adjust arrivals, workers and failures to observe backlog and dead letters. An educational model inspired by the cases, with no production data.
Local deterministic simulation. One step = one second; one worker = one attempt per step; three failures = DLQ. Does not measure production systems.
Time (s)
0
Backlog
0
Completed
0
DLQ
0
Arrived: 0 · Rejected at capacity: 0
To recover: set arrivals to zero, increase workers and advance. Failures affect deterministic IDs; the same message fails again until the configuration changes.
What is being modeled
Each step represents one second. A worker attempts one message per step. Failures return to the queue for up to three attempts, then move to the DLQ. This model has no backoff, persistence or partitions. It illustrates capacity; it does not estimate actual project throughput.