`prefect.server.events.services.event_persister`

The event persister moves event messages from the event bus to storage storage as fast as it can. Never gets tired.

Functions

`create_handler`

create_handler(batch_size: int = 20, flush_every: timedelta = timedelta(seconds=5), queue_max_size: int = 50000, max_flush_retries: int = 5) -> AsyncGenerator[MessageHandler, None]

Set up a message handler that will accumulate and send events to the database every batch_size messages, or every flush_every interval to flush any remaining messages. Event trimming/retention is handled by the db_vacuum service (vacuum_old_events and vacuum_events_with_retention_overrides tasks). Args:

batch_size: Number of events to accumulate before flushing
flush_every: Maximum time between flushes
queue_max_size: Maximum events in queue before dropping new events
max_flush_retries: Consecutive flush failures before dropping events

Classes

`EventPersister`

A service that persists events to the database as they arrive. Methods:

`all_services`

all_services(cls) -> Sequence[type[Self]]

Get list of all service classes

`enabled`

enabled(cls) -> bool

Whether the service is enabled

`enabled_services`

enabled_services(cls) -> list[type[Self]]

Get list of enabled service classes

`environment_variable_name`

environment_variable_name(cls) -> str

`run_services`

run_services(cls) -> NoReturn

Run enabled services until cancelled.

`running`

running(cls) -> AsyncGenerator[None, None]

A context manager that runs enabled services on entry and stops them on exit.

`service_settings`

service_settings(cls) -> ServerServicesEventPersisterSettings

`service_settings`

service_settings(cls) -> ServicesBaseSetting

The Prefect setting that controls whether the service is enabled

`start`

start(self) -> NoReturn

`start`

start(self) -> NoReturn

Start running the service, which may run indefinitely

`started_event`

started_event(self) -> asyncio.Event

`started_event`

started_event(self, value: asyncio.Event) -> None

`stop`

stop(self) -> None

`stop`

stop(self) -> None

Stop the service

​prefect.server.events.services.event_persister

​Functions

​create_handler

​Classes

​EventPersister

​all_services

​enabled

​enabled_services

​environment_variable_name

​run_services

​running

​service_settings

​service_settings

​start

​start

​started_event

​started_event

​stop

​stop

`prefect.server.events.services.event_persister`

Functions

`create_handler`

Classes

`EventPersister`

`all_services`

`enabled`

`enabled_services`

`environment_variable_name`

`run_services`

`running`

`service_settings`

`service_settings`

`start`

`start`

`started_event`

`started_event`

`stop`

`stop`