# Unable to read or write files to HDFS on the Amazon EMR cluster

When running a transformation on an EMR cluster, the transformation appears to run successfully, but an empty file is written to the cluster. When PDI is not installed on the Amazon EC2 instance where you are running your transformation, you are unable to read or write files to the HDFS cluster. Any files written to the cluster are empty.

To resolve this issue, perform the following steps to edit the `hdfs-site.xml` file on the PDI client

:

1. Navigate to the `<username>/.pentaho/metastore/pentaho/NamedCluster/Configs/<user-defined connection name>` directory.
2. Open the `hdfs-site.xml` file with any text editor.
3. Add the following code:

   ```
   <property>
        <name>dfs.client.use.datanode.hostname</name>
        <value>true</value>
   </property>

   ```
4. Save and close the file.


---

# Agent Instructions: 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:

```
GET https://docs.pentaho.com/install/9.3-install/use-hadoop-with-pentaho/big-data-issues/unable-to-read-or-write-files-to-hdfs-on-amazon-emr-cluster.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.