# Prerequisites

Before you begin to work with a Hadoop cluster as a target in Qlik Replicate, make sure that the following prerequisites have been met:

* General:

  * The Hadoop WebHDFS must be accessible from the Qlik Replicate machine.
  * The Hadoop Data Nodes must be accessible from the Qlik Replicate machine.
  * The Hadoop WebHDFS service must be running.

* ODBC Access:

  When accessing Hive using ODBC, the following ODBC drivers are supported:

  * Hortonworks: Cloudera ODBC Driver for Apache Hive 2.06.09.1009 only.

  * Cloudera: Cloudera ODBC Driver for Apache Hive 2.06.09.1009 only.

    Information note

    Cloudera ODBC drivers 2.5.20 or later do not support the [Snappy](https://help.qlik.com/en-US/replicate/November2025/Content/Replicate/Main/Hadoop/advanced_prop_hadoop_target.htm#compression) compression method.

* [](https://help.qlik.com/en-US/replicate/Content/Replicate/Main/Hadoop/prereq_hadoop_gen_target.htm)SSL: Before you can use SSL, you first need to perform the following tasks:

  * Configure each NameNode and each DataNode with an SSL certificate (issued by the same CA).
  * Place the CA certificate on the Replicate Server machine. The certificate should be a base64-encoded PEM (OpenSSL) file.

* Permissions: The user specified in the Hadoop target settings must have write permission for the specified HDFS target directory.