# Using a Cassandra Perl client driver to access Amazon Keyspaces programmatically
<a name="using_perl_driver"></a>

This section shows you how to connect to Amazon Keyspaces by using a Perl client driver. For this code sample, we used Perl 5. Amazon Keyspaces requires the use of Transport Layer Security (TLS) to help secure connections with clients. 

**Important**  
Amazon Keyspacescertificates are transitioning to the Amazon Trust Services (ATS) hierarchy. Ensure your environment trusts the Amazon Root CAs 1–4 to avoid connection errors during this rotation. The Perl driver doesn't validate the server's Amazon SSL certificate, which means that you can't confirm that you are connecting to Amazon Keyspaces. The second step, to configure the driver to use TLS when connecting to Amazon Keyspaces is still required, and ensures that data transferred between the client and server is encrypted. 

1. Download the Cassandra DBI driver from [https://metacpan.org/pod/DBD::Cassandra](https://metacpan.org/pod/DBD::Cassandra) and install the driver to your Perl environment. The exact steps depend on the environment. The following is a common example.

   ```
   cpanm DBD::Cassandra
   ```

1. Create a file for your application.

   ```
   touch cqlapp.pl
   ```

1. Add the following sample code to the cqlapp.pl file.

   ```
   use DBI;
   my $user = "ServiceUserName";
   my $password = "ServicePassword";
   my $db = DBI->connect("dbi:Cassandra:host=cassandra.us-east-2.amazonaws.com;port=9142;tls=1;", 
   $user, $password);
   
   my $rows = $db->selectall_arrayref("select * from system_schema.keyspaces"); 
   print "Found the following Keyspaces...\n"; 
   for my $row (@$rows) { 
         print join(" ",@$row['keyspace_name']),"\n"; 
   } 
   
   $db->disconnect;
   ```
**Important**  
 Ensure that the *ServiceUserName* and *ServicePassword* match the user name and password you obtained when you generated the service-specific credentials by following the steps to [Create service-specific credentials for programmatic access to Amazon Keyspaces](programmatic.credentials.ssc.md). 
**Note**  
For a list of available endpoints, see [Service endpoints for Amazon Keyspaces](programmatic.endpoints.md).

1. Run the application.

   ```
   perl cqlapp.pl
   ```