--- title: "start storage transaction · RUAL Documentation" description: "Opens a storage transaction: every document create, update, remove and restore this flow performs until the end block is journaled so the whole group ca…" canonical: https://docs.rual.nl/block-types/storage/function_transaction_start language: en --- [Cluster](https://docs.rual.nl/cluster) [Blocks](https://docs.rual.nl/block-types) [Interfaces](https://docs.rual.nl/interfaces) [Blueprints](https://docs.rual.nl/blueprints) [Blueprint Language](https://docs.rual.nl/engine) [Tutorials](https://docs.rual.nl/tutorials) [Home automation](https://docs.rual.nl/home-automation) [Examples](https://docs.rual.nl/examples) [Reference](https://docs.rual.nl/reference) [Architecture](https://docs.rual.nl/architecture) [Troubleshooting](https://docs.rual.nl/troubleshooting) Other # start storage transaction This block is part of the [`storage`](https://docs.rual.nl/block-types/storage) group and was last modified in core [`v15.0.1`](https://docs.rual.nl/core-versions/150001). Opens a storage transaction: every document create, update, remove and restore this flow performs until the end block is journaled so the whole group can be reverted as one. - flow `flow` - transaction id `value` Stable identity of this operation (e.g. an order number). Leave empty for a random id : usable for rollback, not for idempotent retry. - name `value` Human label stored on the transaction record. - retention (sec.) `number` How long the journal is kept after the transaction ends. Default 604800 (7 days). Default `604800` - lease (sec.) `number` How long an opener that stopped renewing (crashed) is still considered alive before a retry may revert its attempt. Default 60. Default `60` - revert abandoned attempt `condition` When a previous attempt under the same id is open with an expired lease, revert it before starting fresh (default on). Off fails with TRANSACTION_ABANDONED instead. Default `true` - flow `flow` - success `condition` - transaction id `value` - transaction reference `value` Qualified `bp: : ` form of the id. A transaction belongs to the blueprint that started it; hand this to an end or revert block in ANOTHER blueprint (an operator's repair flow) to address it there. - already committed `condition` True when this id already committed earlier; `result` then carries what the end block stored. - stored result `value` - status `value` started, already_committed, in_progress, abandoned, revert_conflict or simulated. - attempt `number` - abandoned revert report `object` - error `value` Opens a storage transaction for the rest of this flow (and every function it calls). While it is open, every store write : function_create_*, function_update_*, function_remove_*, function_restore_*, function_delete_document, upserts : records the document's state BEFORE the write into a Redis journal, and created documents carry _meta.transaction_id. function_transaction_revert then undoes the journal newest-first, refusing any document whose update_hash moved since; function_transaction_end commits it and stores `result`. NOT an ACID transaction: writes are visible immediately, and bulk ES operations (update by query, reindex, bulk delete) fail with TRANSACTION_UNSUPPORTED_WRITE while one is open. A transaction is identified by the id AND the blueprint that started it (the `transaction_ref` out-pin is the qualified form), so another blueprint cannot read or revert it by guessing the id. With a stable `id` (an order number, account+season) it is also an idempotent-retry gate: a second start of an id that already committed answers already_committed=true with the stored result and does not reopen; one whose previous attempt is still running (its lease is alive) fails with TRANSACTION_IN_PROGRESS; one whose previous attempt died (lease expired) is reverted first when revert_abandoned is on (default) : status revert_conflict and TRANSACTION_REVERT_CONFLICT when that revert could not complete : or fails with TRANSACTION_ABANDONED when it is off. status is one of started, already_committed, in_progress, abandoned, revert_conflict; success is true only for started and already_committed. The journal is kept for `retention` seconds (default 7 days); `lease` seconds (default 60) is how long a crashed opener is still considered alive. In simulation nothing is written and status is simulated. A typical wiring for [start storage transaction](https://docs.rual.nl/block-types/storage/function_transaction_start): a [function trigger](https://docs.rual.nl/block-types/globals/trigger_custom_function) starts the flow; the `flow` out pin feeds [debug](https://docs.rual.nl/block-types/state%2520ui/state_debug). [![Studio canvas example for the start storage transaction block: typical wiring for start storage transaction.](https://docs.rual.nl/canvas-examples/function_transaction_start.png)](https://docs.rual.nl/canvas-examples/function_transaction_start.png?v=3) ## Version history Introduced in [`v15.0.1`](https://docs.rual.nl/core-versions/150001). - [Back to `storage`](https://docs.rual.nl/block-types/storage): Return to the main group to view all sub-groups - [Back to `storage`](https://docs.rual.nl/block-types/storage?group=storage): Return to the group to view all blocks within this group Was this page helpful? [Tell us what to improve](https://docs.rual.nl/support) · RUAL Docs is an integral component of the [RUAL ecosystem](https://rual.nl)