--- tags: - taskflow references: - https://docs.openstack.org/taskflow/latest/user/persistence.html --- Main interface is called Backend. **prep** Backend + (Logbook ->) Flow Detail -> Engine -> Storage **execution** inspect existing atom details -> find unfinished -> inspect graph -> run atoms **post exec** destroy logbook, clear backend can be configured to keep those things around for any purpose > Logbook is the authoritive source of run-time state. Logbook written first, then persisted. Namespace: `taskflow.persistence`. ``` from taskflow.persistence import backends ... persistence = backends.fetch(conf={ "connection": "mysql", "user": ..., "password": ..., }) logbookj ``` Types: - memory (connection: memoery) - files (connection: dir | file) - https://docs.openstack.org/taskflow/latest/user/persistence.html#id5 - sqlalchemy (connection: mysql | postgres | sqlite) - zookeper (connection: zookeeper)