Durable state

Shows a type declared with durable="write", whose state is also kept in the store of the system: each state.set returns after the store has kept the write. Three nodes in the same process share a store over a SQLite file (casty.stores.SQL), take deposits and all stop together, which loses every replica. Three new nodes start on the same file and each account comes back with its last confirmed balance, while a type kept only in memory starts over from zero. The same store takes the URL of a PostgreSQL, MySQL or MariaDB database, which nodes on several machines reach.

Needs local TCP ports 7451 to 7453 to be free. The store file is kept in a temporary directory.

cd examples/11-durable-state
uv run main.py