Hello, Cyberax, you wrote: a C> Hello, Sharov, you wrote: S>> the Question: as well as on what similar storage is better for organizing - mysql, nosql. There is something similar ? The task unpretentious, the decision for certain . Not one decade. It would not be desirable to invent a bicycle. The C> Is some variants. As my preferences: a C> 1) to Throw out on three letters RabbitMQ and simply to make queue of tasks. Working nodes periodically interrogate it, taking away jobs. The taken away jobs thus are marked at once as "in process". The logic with , falling, etc. is elementarily added if needed directly in request "give-me-following-task". Well and simple table MySQL/PostgreSQL will be scaled to hundreds tasks a second. To throw out not a variant, not my moped.> 2) If so it would be desirable to eat a C a cactus we do the message "the task it is received" idempotent and it is combined with a template "the invisible message". I.e. The working node takes the message, without confirming it, and sends on a central node acknowledgement "ja-ja-work". In case of falling (after a while) the message again becomes visible and other node starts it to execute, repeatedly sending "ja-ja-work". I somehow and planned to make, was then clarified that the come message is necessary ack, . Queue removes it. Above like conciliatory proposals with double ack have been found. Cs> In my practice, with a state on messages result difficult protocols only in so I would begin with 1). At us yet the difficult protocol, and hardly becomes difficult.