> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prefect.io/llms.txt
> Use this file to discover all available pages before exploring further.
# task_run_recorder
# `prefect.server.services.task_run_recorder`
## Functions
### `task_run_from_event`
```python theme={null}
task_run_from_event(event: ReceivedEvent) -> TaskRun
```
### `db_recordable_task_run_from_event`
```python theme={null}
db_recordable_task_run_from_event(event: ReceivedEvent) -> tuple[TaskRun, dict[str, Any]]
```
### `record_task_run_event`
```python theme={null}
record_task_run_event(event: ReceivedEvent, depth: int = 0) -> None
```
Record a single task run event in the database.
Delegates to `record_bulk_task_run_events`, which already retries once on
`IntegrityError` to recover from TOCTOU races against concurrent recorders.
Any `IntegrityError` that survives the retry is treated as an unrecoverable
duplicate and the event is discarded.
### `record_bulk_task_run_events`
```python theme={null}
record_bulk_task_run_events(events: list[ReceivedEvent]) -> None
```
Record multiple task run events in the database, taking advantage of bulk inserts.
Retries once on `IntegrityError` to handle TOCTOU races between concurrent
recorder instances: when two batches reference the same `task_run.id` with
different natural keys, one batch's existence-check SELECT may run before
the other batch's INSERT commits. The retry re-runs the SELECT in a fresh
session so the conflict target is chosen against the now-visible row.
### `consumer`
```python theme={null}
consumer(write_batch_size: int, flush_every: int, max_persist_retries: int = DEFAULT_PERSIST_MAX_RETRIES) -> AsyncGenerator[MessageHandler, None]
```
## Classes
### `RetryableEvent`
### `TaskRunRecorder`
Constructs task runs and states from client-emitted events
**Methods:**
#### `all_services`
```python theme={null}
all_services(cls) -> Sequence[type[Self]]
```
Get list of all service classes
#### `enabled`
```python theme={null}
enabled(cls) -> bool
```
Whether the service is enabled
#### `enabled_services`
```python theme={null}
enabled_services(cls) -> list[type[Self]]
```
Get list of enabled service classes
#### `environment_variable_name`
```python theme={null}
environment_variable_name(cls) -> str
```
#### `run_services`
```python theme={null}
run_services(cls) -> NoReturn
```
Run enabled services until cancelled.
#### `running`
```python theme={null}
running(cls) -> AsyncGenerator[None, None]
```
A context manager that runs enabled services on entry and stops them on
exit.
#### `service_settings`
```python theme={null}
service_settings(cls) -> ServicesBaseSetting
```
#### `service_settings`
```python theme={null}
service_settings(cls) -> ServicesBaseSetting
```
The Prefect setting that controls whether the service is enabled
#### `start`
```python theme={null}
start(self, max_persist_retries: int = DEFAULT_PERSIST_MAX_RETRIES) -> NoReturn
```
#### `start`
```python theme={null}
start(self) -> NoReturn
```
Start running the service, which may run indefinitely
#### `started_event`
```python theme={null}
started_event(self) -> asyncio.Event
```
#### `started_event`
```python theme={null}
started_event(self, value: asyncio.Event) -> None
```
#### `stop`
```python theme={null}
stop(self) -> None
```
#### `stop`
```python theme={null}
stop(self) -> None
```
Stop the service