sessioned

sessioned()

Decorator that enables sticky sessions on a Server.

Every request must carry a session token obtained from a session start request; requests with the same token are routed to the same container until the session is idle for idle_timeout seconds or explicitly terminated. A container won't be scaled down for as long as it holds a live session.

Only valid with @app.server().

Usage

Define a Server with the @modal.sessioned() decorator:

app = modal.App("my-app")

@app.server(port=8000)
@modal.sessioned()
class MyServer:
    @modal.enter()
    def start(self):
        self.proc = subprocess.Popen(["python3", "-m", "http.server", "8000"])

    @modal.exit()
    def stop(self):
        self.proc.terminate()

After deploying the App, start a session from another script:

server = modal.Server.from_name("my-app", "MyServer")
server_url = server.get_url()
session = server.sessions.start(idle_timeout=600)
headers = {"Modal-Authorization": f"Bearer {session.token}"}

requests.get(server_url, headers=headers).raise_for_status()

server.sessions.terminate(session.token)