Streaming API¶
Streaming API for real-time point value and device alarm data streams.
Concepts & Glossary¶
| Term | Description |
|---|---|
| Point Stream | A Point Stream determines the real-time data flow for specific sensor points (e.g., temperature, pressure) from IoT devices to registered webhook endpoints over a defined period. |
| Alarm Stream | An Alarm Stream determines the real-time data flow for alarm events from selected devices to registered webhook endpoints. |
| Webhook Registration | Webhook Registration is the process where clients register HTTP endpoints to receive real-time notifications for point and alarm stream events. |
| Event Publishing | Event Publishing is the process where backend systems publish point and alarm events for processing and delivery to registered webhooks. |
| Partition | A Partition represents a logical grouping or tenant boundary that isolates streaming subscriptions and events for different customers or organizational units. |
| Stream Subscription | A Stream Subscription defines which specific entities a webhook endpoint wants to monitor (point IDs for point streams, device IDs for alarm streams). |
| Webhook Secret | A Webhook Secret is a shared key used to authenticate and verify the integrity of webhook deliveries using HMAC signatures for secure communication. |
| Dead Letter Queue | A Dead Letter Queue (DLQ) stores failed webhook delivery attempts for manual review and reprocessing when endpoints are temporarily unavailable. |
Streaming performance and limits¶
This section describes the request limits for the Streaming API and the load levels that were validated during performance testing. Use it to plan the size of your subscriptions and the capacity of your webhook endpoints.
- Request limits are the maximum values allowed in a single request. Keep each request within these limits.
- Tested capacity describes load levels that were successfully verified. It is not a hard limit or a guaranteed service level. Actual throughput depends on your data volume, event frequency, and how fast your webhook endpoint responds.
Point data (COV) streams¶
Point streams deliver change-of-value (COV) updates for the points that you register.
| Type | Value | Description |
|---|---|---|
| Request limit | 1,000 points per request | Maximum number of points that you can register in a single POST or PATCH request. |
| Tested capacity | 5,000 registered points | Streaming was successfully tested with 5,000 registered points and a COV interval of 5 minutes. |
To register more than 1,000 points, split the points into batches of up to 1,000 and send one request per batch.
Device alarm event streams¶
Alarm streams deliver alarm events from the devices that you register.
| Type | Value | Description |
|---|---|---|
| Tested capacity | 10,000 alarm events | Streaming was successfully tested with alarm events generated sequentially in batches of 1,000, up to 10,000 events in total. |
Recommendations¶
- Make sure that your webhook endpoint responds quickly and can handle bursts of events, especially when many points change value or many alarms are raised at the same time.
- If you plan to stream more data than the tested capacity, test with your expected load before you go to production.