capp/src/manager/mailbox.rs currently gives each worker its own bounded mpsc inbox (default inbox_capacity = 1) and the dispatcher pushes envelopes via strict round-robin: next_worker = (next_worker + 1) % n. When the chosen worker is busy, inboxes[idx].send().await blocks indefinitely — even if the other workers are idle. Throughput collapses to the slowest worker.
capp/src/manager/mailbox.rscurrently gives each worker its own bounded mpsc inbox (defaultinbox_capacity = 1) and the dispatcher pushes envelopes via strict round-robin:next_worker = (next_worker + 1) % n. When the chosen worker is busy,inboxes[idx].send().awaitblocks indefinitely — even if the other workers are idle. Throughput collapses to the slowest worker.