Add example

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Aaron Crawfis 2021-01-15 16:16:31 -08:00
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@ -18,7 +18,7 @@ In some components, such as Kafka, time-to-live can be configured in the topic v
When message time-to-live has native support in the component, Dapr will simply forward the time-to-live configuration without adding extra logic, keeping predictable behavior. This is helpful when the expired messages are handled differently by the component - like in Azure Service Bus, where expired messages are stored in the dead letter queue and not simply deleted.
### Components with native message TTL support
### Supported components
#### Azure Service Bus
@ -28,4 +28,45 @@ Azure Service Bus supports [entity level time-to-live]((https://docs.microsoft.c
If messages are consumed by subscribers without Dapr, expired messages are not automatically dropped, as expiration is handled by the Dapr runtime when a Dapr application receives a message. However, subscribers can programmatically drop expired messages by adding logic to handle the `expiration` attribute in the cloud event, which follows the [RFC3339](https://tools.ietf.org/html/rfc3339) format.
When non-Dapr subscribers use components such as Azure Service Bus, which natively handle message TTL, they will not receive expired messages. No extra logic is needed.
When non-Dapr subscribers use components such as Azure Service Bus, which natively handle message TTL, they will not receive expired messages. No extra logic is needed.
## Example
Message TTL can be set in the metadata as part of the publishing request:
{{< tabs curl "Python SDK">}}
{{% codetab %}}
```bash
curl -X "POST" http://localhost:3500/v1.0/publish/pubsub/TOPIC_A?metadata.ttlInSeconds=120 -H "Content-Type: application/json" -d '{"order-number": "345"}'
```
{{% /codetab %}}
{{% codetab %}}
```python
from dapr.clients import DaprClient
with DaprClient() as d:
req_data = {
'order-number': '345'
}
# Create a typed message with content type and body
resp = d.publish_event(
pubsub_name='pubsub',
topic='TOPIC_A',
data=json.dumps(req_data),
metadata=(
('ttlInSeconds', '120')
)
)
# Print the request
print(req_data, flush=True)
```
{{% /codetab %}}
{{< /tabs >}}
See [this guide]({{< ref pubsub_api.md >}}) for a full reference on the pub/sub API.
## Related links
- [Pub/sub API reference]({{< ref pubsub_api.md >}})