---
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title: Troubleshooting Aggregators Module
collection: mulesoft
version: current
locale: en-us
portal_url: https://docs.salesforce.com/mulesoft/current/en-us/aggregators-module/1.0/aggregators-troubleshooting.md
canonical_url: https://docs.mulesoft.com/aggregators-module/1.0/aggregators-troubleshooting
source_site: docs.mulesoft.com
content_type: documentation
content_hash: 048dcaa20e283c7204ef00a00005a602cf9143de92c1605245fea9e8c536d5fa
description: MuleSoft Documentation Site
release: "1.0"
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---
---
product: Aggregators Module
version: 1.0
---

# Troubleshooting Aggregators Module

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

To troubleshoot the Aggregators module, become familiar with the information about app logs,
enabling verbose logging, and interpreting commonly thrown messages.

## Use the Latest Aggregators Module Version

To ensure that you use the latest patches, update the Aggregator module to the latest version. In
the Apache Maven `pom.xml` file generated by Anypoint Studio, replace `x.x.x` with the version that
corresponds to the latest version:

```xml
<dependency>
  <groupId>org.mule.modules</groupId>
  <artifactId>mule-aggregators-module</artifactId>
  <version>x.x.x</version>
  <classifier>mule-plugin</classifier>
</dependency>
```

To obtain the most up-to-date `pom.xml` file information:

1.  Go to [Anypoint Exchange](https://www.mulesoft.com/exchange/).

2.  In Exchange, click **Login** and supply your Anypoint Platform username and password.

3.  In Exchange, search for `aggregators`.

4.  Select the connector.

5.  Click **Dependency Snippets** near the upper right of the screen.

## Enable Verbose Logging

To begin troubleshooting Aggregator module, enable verbose logging to see the exact error messages:

1.  Access Anypoint Studio and navigate to the **Package Explorer** view.

2.  Open your application’s project.

3.  Open the `src/main/resources` path folder.

4.  Open the `log4j2.xml` file inside the folder.

5.  If the following line is already in the `log4j2.xml` file, uncomment it to enable it; otherwise,
    add it:

    ```xml
    <AsyncLogger name="org.mule.extension.aggregator" level="DEBUG"/>
    ```

6.  Save your changes.

7.  Click the project name in **Package Explorer** and then click **Run** > **Run As** > **Mule
    Application**.

8.  Navigate to the **Console** view to read the messages in the logger.

## Understand the Timeout Behavior in the Size-Based Aggregator

For the **Size based aggregator** scope, the **Timeout** field indicates the maximum time to wait
for the aggregation to complete. If the timeout is reached before the total number of elements is
equal to the value set in the **Max size** field, the aggregation is not considered complete and the
aggregation is reset. Note that you can use an **Aggregator listener** source to capture the
elements that were aggregated before the timeout occurred. For further details on timeout behavior,
see how to
[configure the Size-Based Aggregator Timeout and Max Size Fields](https://docs.mulesoft.com/aggregators-module/1.0/aggregators-size-timeout)
documentation.

## Make Sure You Are Not in a Multiple Worker Setting

Aggregators don’t work with multiple workers and a persistent object store because clustering is not
available in CloudHub. For details on how workers can be shared or doubled to scale your application
and provide high availability, see the [CloudHub Fabric](https://docs.mulesoft.com/cloudhub/cloudhub-fabric)
documentation.

## Understand Common Throws

Here is a list of common throw messages and how to interpret them:

For **Size based aggregator**:

- AGGREGATORS:AGGREGATOR\_CONFIG

  The Max size or Timeout fields have invalid values, for example, Max size < 0.

- AGGREGATORS:OBJECT\_STORE\_ACCESS

  An error occurred during an attempt to access the object store used to store the aggregated
  values.

For **Time based aggregator**:

- AGGREGATORS:AGGREGATOR\_CONFIG

  The Period or Max size fields have invalid values, for example, Period = 0.

- AGGREGATORS:OBJECT\_STORE\_ACCESS

  An error occurred during an attempt to access the object store used to store the aggregated
  values.

For **Group based aggregator**:

- AGGREGATORS:GROUP\_COMPLETED

  An error occurred during an attempt to add a new element to an already completed group that was
  not yet evicted.

- AGGREGATORS:GROUP\_TIMED\_OUT

  An error occurred during an attempt to add a new element to a group that timed out but had not yet
  been evicted.

- AGGREGATORS:NO\_GROUP\_ID

  The expression that resolves to the group ID returns null.

- AGGREGATORS:NO\_GROUP\_SIZE

  The expression that resolves to the group size returns null.

- AGGREGATORS:AGGREGATOR\_CONFIG

  The Group size or Timeout fields have invalid values, for example, groupSize < 0.

- AGGREGATORS:OBJECT\_STORE\_ACCESS

  An error occurred during an attempt to access the object store used to store the aggregated
  values.

## See Also

- [Salesforce Help](https://help.salesforce.com)

- [Aggregators Module Reference](https://docs.mulesoft.com/aggregators-module/1.0/aggregators-module-reference)