> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/install/9.3-install/pentaho-configuration/tasks-to-be-performed-by-an-it-administrator/set-up-the-adaptive-execution-layer-ael/troubleshooting-ael-cp/message-size-exceeded.md). # Message size exceeded If you are using the Spark engine to run an AEL transformation and an error is generated indicating a decoded message was too big for the output buffer, you need to increase the maximum size (2 MB by default) of the message buffers for your AEL environment. Perform the following steps to increase the message buffer limit: 1. [Stop the AEL daemon](/install/9.3-install/pentaho-configuration/tasks-to-be-performed-by-an-it-administrator/set-up-the-adaptive-execution-layer-ael/configure-the-ael-daemon-for-yarn-mode.md). 2. Navigate to the `data-integration/adaptive-execution/config` directory and open the `application.properties` file using a text editor. 3. Enter the following incoming WebSocket message buffer properties, setting the same value for each property: \
PropertyValue
daemon.websocket.maxMessageBufferSize

The maximum size (in bytes) for the message buffer on the AEL daemon. For example, to allocate a 4 MB limit, set the memory value as shown here:```daemon.websocket.maxMessageBufferSize=4000000


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**driver.websocket.maxMessageBufferSize**

\
 The maximum size (in bytes) for the message buffer on the AEL Spark driver. For example, to allocate a 4 MB limit, set the memory value as shown here:\`\`\` **driver.websocket.maxMessageBufferSize**=4000000
4\. Save and close the file. 5. [Restart the AEL daemon](/install/9.3-install/pentaho-configuration/tasks-to-be-performed-by-an-it-administrator/set-up-the-adaptive-execution-layer-ael/configure-the-ael-daemon-for-yarn-mode.md). When the AEL daemon submits the AEL Spark driver application, it passes the driver’s maximum message buffer size value as part of the submit; then, when the driver application is started, it receives the maximum buffer size value sent by the daemon. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.pentaho.com/install/9.3-install/pentaho-configuration/tasks-to-be-performed-by-an-it-administrator/set-up-the-adaptive-execution-layer-ael/troubleshooting-ael-cp/message-size-exceeded.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.