--- schema_version: "1" id: 121eae276021d0352b4ab394c748e350297c09e13eb8c969d520329c6d935373 title: Size-Based Aggregator Example collection: mulesoft version: current locale: en-us portal_url: https://docs.salesforce.com/mulesoft/current/en-us/aggregators-module/latest/aggregators-size-example.md canonical_url: https://docs.mulesoft.com/aggregators-module/latest/aggregators-size-example source_site: docs.mulesoft.com content_type: documentation content_hash: 0080a1c332335d6001978c8bcf7b139bdc465c28490d5d78f6a7eb6c7c19840f description: MuleSoft Documentation Site release: "1.1" latest: true --- --- product: Aggregators Module version: 1.1 is-latest-version: true --- # Size-Based Aggregator Example > For the full documentation index, see: https://docs.mulesoft.com/llms.txt The Aggregators module **Size based aggregator** scope enables you to aggregate elements until a predefined size number of elements completes the aggregation. The following example shows how to configure this scope to aggregate up to `3` HTTP request calls. The application uses DataWeave to set the payload of each call with a random ID number. When the aggregation reaches the `3` calls required for completion, the application logs all the aggregated random ID number elements. ![Size-Based Aggregator Flow Example in Anypoint Studio Canvas](/mulesoft/current/en-us/aggregators-module/latest/_images/aggregator-size-example.png) Figure 1. Size-Based Aggregator Flow Example To test this example in your own environment, you must create the Mule application and test it with curl commands. ## Create the Mule Application To create the Mule flow in Anypoint Studio: 1. In **Mule Palette**, select **HTTP Listener** and drag it onto the canvas. The source initiates the flow by listening for incoming HTTP message attributes. 2. In **Connector configuration**, select **HTTP\_Listener\_config**. 3. Set **Path** to `/test`. 4. Drag a **Transform message** component to the right of **Listener**. 5. In the DataSense preview window of the **Transform message** component, add the following DataWeave expression, which sets to each HTTP request payload a `Source Name` as `"size-based"` and a `Source ID` as `random() as String`: ```DataWeave %dw 2.0 output application/json --- { "Source Name": "size-based", "Source ID": (random() as String) } ``` 6. Drag the **Size based aggregator** scope to the right of **Transform message**. 7. Set **Name** to `sizeBasedAggregator`. 8. Set **Max size** to `3`. 9. Set **Content** to `payload`, which is the expression that defines what to aggregate: in this case, the transformed HTTP requests. 10. Drag a **Logger** component into the **Incremental aggregation** route. 11. In the **Logger** configuration screen, set **Message** to `Doing incremental aggregation step.` 12. Drag a **Logger** component into the **Aggregation complete** route. 13. Set **Message** to `Aggregation complete`. 14. Drag another **Logger** component to the right of the first **Logger** component in **Aggregation complete**. 15. Set **Message** to the following expression, which returns all the aggregated elements: ```xml output application/json --- payload ``` 16. Save the project. 17. In **Package Explorer**, click **Run > Run As > Mule Application**. 18. Test the app by sending the following curl command three times: `curl -X POST [http://localhost:8086/test](http://localhost:8086/test)` This generates three HTTP requests for the **Size based aggregator** to process. 19. Navigate to the **Console** view to read the logger message: ```none INFO 2021-06-08 11:18:44,897 [[MuleRuntime].uber.02: [aggregator-size-demo].aggregator-size-demoFlow.CPU_INTENSIVE @20a8a5b4] [processor: aggregator-size-demoFlow/processors/1/route/0/processors/0; event: 6ee63ec0-c864-11eb-b5a7-f01898ad2638] org.mule.runtime.core.internal.processor.LoggerMessageProcessor: Doing incremental aggregation step. INFO 2021-06-08 11:18:48,570 [[MuleRuntime].uber.02: [aggregator-size-demo].aggregator-size-demoFlow.CPU_INTENSIVE @20a8a5b4] [processor: aggregator-size-demoFlow/processors/1/route/0/processors/0; event: 71283f80-c864-11eb-b5a7-f01898ad2638] org.mule.runtime.core.internal.processor.LoggerMessageProcessor: Doing incremental aggregation step. INFO 2021-06-08 11:18:50,189 [[MuleRuntime].uber.02: [aggregator-size-demo].aggregator-size-demoFlow.CPU_INTENSIVE @20a8a5b4] [processor: aggregator-size-demoFlow/processors/1/route/1/processors/0; event: 721efb90-c864-11eb-b5a7-f01898ad2638] org.mule.runtime.core.internal.processor.LoggerMessageProcessor: Aggregation complete INFO 2021-06-08 11:18:50,254 [[MuleRuntime].uber.02: [aggregator-size-demo].aggregator-size-demoFlow.CPU_INTENSIVE @20a8a5b4] [processor: aggregator-size-demoFlow/processors/1/route/1/processors/1; event: 721efb90-c864-11eb-b5a7-f01898ad2638] org.mule.runtime.core.internal.processor.LoggerMessageProcessor: [ { "Source Name": "size-based", "Source ID": "0.49127866969631506" }, { "Source Name": "size-based", "Source ID": "0.4250959269275998" }, { "Source Name": "size-based", "Source ID": "0.4160926509813687" } ] ``` This example logger message shows that for the first two HTTP requests, the **Logger** component in the **Incremental aggregator** route logs the message `Doing incremental aggregation step.` After the aggregation reaches the third HTTP request call, the first **Logger** component in the **Aggregation complete** route logs the message `Aggregation complete`, and the second **Logger** component returns the aggregated payload elements, which are the random ID numbers: ```none { "Source Name": "size-based", "Source ID": "0.49127866969631506" }, { "Source Name": "size-based", "Source ID": "0.4250959269275998" }, { "Source Name": "size-based", "Source ID": "0.4160926509813687" } ``` ## XML for Size-Based Aggregator Example Paste this code into your Studio XML editor to quickly load the flow for this example into your Mule app: ```xml ``` ## See Also - [Aggregators Module Examples](https://docs.mulesoft.com/aggregators-module/latest/aggregators-examples) - [Salesforce Help](https://help.salesforce.com)