Initiate and terminate the connection to the database

The app must be opened at the beginning of the program to create the connection pool to the database, and eventually closed to properly terminate it.

The app implements several ways to do this.

Explicitly open and close the app

The app can be opened using the open method (for sync case) or open_async method (for async case). It eventually needs to be closed, using the close method (for sync case) or close_async (for async case).

For sync case:

For async case:

await app.open_async()
await app.close_async()

Open and close the app with a context manager

The app can be opened with a context manager, which will automatically close it when leaving the context.

For sync case:


For async case:

async with app.open_async():

Create and open the app in a single line

Both open and open_async return the current app when they are called or entered, which allows you to instantiate and open your app in a single line.

For sync case:

app = procrastinate.App(connector=connector).open()

Open the app, and let the garbage collector terminate the connection

The app does not necessarily need to be closed at the end of your program. The connections to the database will be automatically terminated when the database connector is garbage collected. Thus, your program can work with only the following statements, as we did in the readme and the quickstart:

app = procrastinate.App(connector=connector)

But remember: “explicit is better than implicit”.

Use an external pool instead of the connectors default pool

The database connectors instantiate their own connection pool by default. You can overwrite this behavior and supply your own pool, passing it as an argument to the open and open_async functions.