Best Practices for Configuring HAWQ Parameters
The configuration parameters for HAWQ are maintained in the $GPHOME/etc/hawq-site.xml file. This file resides on all HAWQ instances and can be modified either via Ambari or by using the HAWQ command line interface. Use a consistent strategy (Ambari or command line interface) to maintain the contents of hawq-site.xml.
For Ambari-managed clusters, always use Ambari for configuring hawq-site.xml parameters; restarting or reconfiguring HAWQ via Ambari will overwrite any configuration changes to hawq-site.xml made outside the Ambari interface.
If you manage your cluster using command line tools instead of Ambari, use a consistent hawq-site.xml file to configure your entire cluster.
Note: Do not configure HAWQ parameters through the postgresql.conf file. Use only hawq-site.xml to configure your HAWQ cluster. Any parameters defined in hawq-site.xml will overwrite parameters in postgresql.conf.