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In this blog post, we’ll walk through Eventstream’s pricing model to give you a clear understanding of how it works and help you navigate it with confidence.
By the end of this post, you will be able to:
First, let's summarize the components of a Fabric Eventstream:
Each component maps to one or more of the four Eventstream operation types (billing meters). These operation types define how Eventstream activity is represented in the Fabric Capacity Metrics app and how they contribute to Fabric consumption.
The following reference table outlines how Eventstream components correspond to each operation type. Note that certain components may map to one or more operation types:
| Eventstream Component | Operation Type | Description of Operation Type | Operation unit of measure | Fabric consumption rate |
| Eventstream Per Hour | Flat charge | Per hour | 0.222 capacity unit (CU) hours | |
| Streams (default and derived) | Eventstream Data Traffic Per GB | Data ingress and egress volume in default and derived streams (includes 24-hour retention) | Per gigabyte | 0.342 CU hours |
| Operators and some input sources | Eventstream Processor Per Hour | Computing resources that the processor consumes | Per hour | Starts at 0.778 CU hours and autoscales 2 per throughput |
| Input sources leveraging connector | Eventstream Connectors Per vCore Hour | Computing resources that the connectors consume | Per hour | 0.611 CU hours per vCore |
Flow_diagram_Input_Source_Default_Stream_Operator_Derived_Stream_Destination
Flow diagram: Input Source → Default Stream → Operator → Derived Stream → Destination.
Input source(s) represents where your data comes from in an Eventstream. You can connect to different types of sources, and pricing is based on how they operate.
Most Eventstream sources fall under ‘connectors’, meaning they incur the cost of Connector vCore per hour meter (e.g., Azure SQL DB, Cosmos DB, Service Bus, etc.).
Other sources do not incur the connector cost and instead incur the Eventstream Processor Per Hour meter charge (e.g. Azure Event Hubs, Azure IoT Hub).
Billing is determined by how each source brings data into Fabric.
There are two types of streams in an Eventstream topology. Default Stream is present in all Eventstreams, and additionally, you can create a Derived Stream.
A derived stream refers to a logical stream of data which is created by applying transformations to the default stream after adding operators such as filtering and aggregations. Derived streams can be accessed independently from default streams for additional consumption or analysis through the Real-Time Hub.
For billing purposes, the Eventstream Data Traffic per GB meter is calculated based on the volume of data entering (ingress) and exiting (egress) each stream within your Eventstream topology, as illustrated below:
Flow_diagram_with_two_branches_Input_Source_Default_Stream_Transform_Operator_De
Operators (configured through no-code options or SQL) enable the application of processing logic within your Eventstream, including filtering, enrichment, and routing. Billing is determined by the number of processing routes defined in the Eventstream, representing the paths through which data flows from sources, through processing steps, to their respective outputs:
Flow_diagram_with_three_processing_routes_from_Default_Stream_Processing_route_1
The Eventstream Processor Per Hour meter is determined by the number of processing routes defined within your Eventstream.
Separately, the throughput setting serves as a lever to manage how the system scales. Eventstream automatically adjusts compute resources to maintain low latency, and billing reflects the compute that is actually consumed. By configuring throughput, you establish an upper limit on system scaling, which can also support cost management.
In Fabric Eventstreams, destinations fall into two categories:
We will now examine several examples to calculate CU consumption based on the Eventstream components involved.
Flow_diagram_Source_Custom_endpoint_Default_Stream_Destination_Eventhouse_Direct
The set-up:
For this set-up, the meter calculation would be as follows:
| Operation in Capacity Metrics App | Description | Operation unit of measure | Fabric consumption rate | Calculation |
| Eventstream Per Hour | Flat charge | Per hour | 0.222 CU hour | 0.22 per hour |
| Eventstream Data Traffic per GB | Data ingress & egress volume in default and derived streams (Includes 24-hour retention) | Per GB | 0.342 CU hour | 0.08 GB (.04 GB ingress+.04 GB egress) of data X .342 = 0.03 per hour |
| Eventstream Processor Per Hour | Computing resources consumed by the processor | Per hour | Starts at 0.778 CU hour and autoscale per throughput | 0 X .778 = 0 per hour |
| Eventstream Connectors Per vCore Hour | Computing resources consumed by the connectors | Per hour | 0.611 CU hour per vCore | 0 X .611 = 0 per hour |
| SUM = 0.25 CU per hour |
This Eventstream topology consumes 0.25 CU per hour.
Recommended SKU for this Eventstream alone: F2 (87% unused)
Flow_diagram_Source_Connector_Default_Stream_two_branches_Operator_1_Filter_Dest
The set-up:
For this set-up, the meter calculation would be as follows:
| Operation in Capacity Metrics App | Description | Operation unit of measure | Fabric consumption rate | Calculation |
| Eventstream Per Hour | Flat charge | Per hour | 0.222 CU hour | 0.22 per hour |
| Eventstream Data Traffic per GB | Data ingress & egress volume in default and derived streams (Includes 24-hour retention) | Per GB | 0.342 CU hour | 0.12 GB (.04 GB ingress + (2 x .04 GB egress)) x .342 = 0.04 per hour |
| Eventstream Processor Per Hour | Computing resources consumed by the processor | Per hour | Starts at 0.778 CU hour and autoscale per throughput | 2 X .77 = 1.55 per hour |
| Eventstream Connectors Per vCore Hour | Computing resources consumed by the connectors | Per hour | 0.611 CU hour per vCore | 1 X .611 = 0.61 per hour |
| SUM = 2.42 CU per hour |
This Eventstream topology consumes 2.42 CU per hour.
Recommended SKU for this Eventstream alone: F4
This example shows how the same processing logic results in different processing charges based on the amount of data. As traffic increases, Eventstream scales compute, and the Eventstream Processor Per Hour cost grows accordingly.
The set-up (common across except for traffic levels):
| Operation in Capacity Metrics App | Description | Operation unit of measure | Fabric consumption rate | Calculation |
| Eventstream Per Hour | Flat charge | Per hour | 0.222 CU hour | 0.22 per hour |
| Eventstream Data Traffic per GB | Data ingress & egress volume in default and derived streams (Includes 24-hour retention) | Per GB | 0.342 CU hour | 2 GB (1 in + 1 out) × 0.342 = 0.68 per hour |
| Eventstream Processor Per Hour | Computing resources consumed by the processor | Per hour | Starts at 0.778 CU hour and autoscale per throughput | 1 × 0.778 = 0.77 CU per hour |
| Eventstream Connectors Per vCore Hour | Computing resources consumed by the connectors | Per hour | 0.611 CU hour per vCore | 1 × 0.611 = 0.61 per hour |
| SUM = 2.28 CU per hour |
Recommended SKU for Example 3A: F4
| Operation in Capacity Metrics App | Description | Operation unit of measure | Fabric consumption rate | Calculation |
| Eventstream Per Hour | Flat charge | Per hour | 0.222 CU hour | 0.22 per hour |
| Eventstream Data Traffic per GB | Data ingress & egress volume in default and derived streams (Includes 24-hour retention) | Per GB | 0.342 CU hour | 20 GB (10 in + 10 out) × 0.342 = 6.84 per hour |
| Eventstream Processor Per Hour | Computing resources consumed by the processor | Per hour | Starts at 0.778 CU hour and autoscale per throughput | 1 × (0.778 x 3*) = 2.33 CU per hour *1 base rate (2.33 CU hours) |
| Eventstream Connectors Per vCore Hour | Computing resources consumed by the connectors | Per hour | 0.611 CU hour per vCore | 1 × 0.611 = 0.61 per hour |
| SUM = 10.00 CU per hour |
Recommended SKU for Example 3B: F16
The cost of operating Eventstream is determined by several factors:
While this blog post helps calculate CU consumption, we recommend running your Eventstream in a realistic, steady-state configuration for a period of time—ideally 24 hours—to observe actual consumption patterns.
The Microsoft Fabric Capacity Estimator can also be used to assist in cost planning, as it estimates the capacity requirements of an Eventstream based on your input parameters. It is important to consider any additional Fabric workloads, such as Eventhouse, Lakehouse, or Notebooks, since all services draw from the same capacity pool.
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Questions? Reach out via email at askeventstreams@microsoft.com.
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