Initializing PXF

PXF Configuration Properties
Prerequisites
Procedure
Resetting PXF
- Procedure

You must explicitly initialize the PXF service instance. This one-time initialization creates the PXF service web application and generates PXF configuration files and templates.

PXF provides two management commands that you can use for initialization:

pxf cluster init - initialize all PXF service instances in the Greenplum Database cluster
pxf init - initialize the PXF service instance on the current Greenplum Database host

PXF also provides similar reset commands that you can use to reset your PXF configuration.

PXF Configuration Properties

PXF supports both internal and user-customizable configuration properties. Initializing PXF generates PXF internal configuration files, setting default properties specific to your configuration. Initializing PXF also generates configuration file templates for user-customizable settings such as custom profiles and PXF runtime and logging settings.

PXF internal configuration files are located in your Greenplum Database installation in the $GPHOME/pxf/conf directory. You identify the PXF user configuration directory at PXF initialization time via an environment variable named $PXF_CONF. If you do not set $PXF_CONF prior to initializing PXF, PXF may prompt you to accept or decline the default user configuration directory, $HOME/pxf, during the initialization process.

Note: Choose a $PXF_CONF directory location that you can back up, and ensure that it resides outside of your Greenplum Database installation directory.

During initialization, PXF creates the $PXF_CONF directory if necessary, and then populates it with subdirectories and template files. Refer to PXF User Configuration Directories for a list of these directories and their contents.

Prerequisites

Before initializing PXF in your Greenplum Database cluster, ensure that:

Your Greenplum Database cluster is up and running.
You have identified the PXF user configuration directory filesystem location, $PXF_CONF, and that the gpadmin user has the necessary permissions to create, or write to, this directory.

Procedure

Perform the following procedure to initialize PXF on each segment host in your Greenplum Database cluster.

Log in to the Greenplum Database master node:
```
$ ssh gpadmin@<gpmaster>
```
Run the pxf cluster init command to initialize the PXF service on the master, standby master, and on each segment host. For example, the following command specifies /usr/local/greenplum-pxf as the PXF user configuration directory for initialization:
```
gpadmin@gpmaster$ PXF_CONF=/usr/local/greenplum-pxf $GPHOME/pxf/bin/pxf cluster init
```
The init command creates the PXF web application and initializes the internal PXF configuration. The init command also creates the $PXF_CONF user configuration directory if it does not exist, and populates the conf and templates directories with user-customizable configuration templates. If $PXF_CONF exists, PXF updates only the templates directory.

Note: The PXF service runs only on the segment hosts. However,pxf cluster init also sets up the PXF user configuration directories on the Greenplum Database master and standby master hosts.

Resetting PXF

Should you need to, you can reset PXF to its uninitialized state. You might choose to reset PXF if you specified an incorrect PXF_CONF directory, or if you want to start the initialization procedure from scratch.

When you reset PXF, PXF prompts you to confirm the operation. If you confirm, PXF removes the following runtime files and directories (where PXF_HOME=$GPHOME/pxf):

$PXF_HOME/conf/pxf-private.classpath
$PXF_HOME/pxf-service
$PXF_HOME/run

PXF does not remove the $PXF_CONF directory during a reset operation.

You must stop the PXF service instance on a segment host before you can reset PXF on the host.

Procedure

Perform the following procedure to reset PXF on each segment host in your Greenplum Database cluster.

Log in to the Greenplum Database master node:
```
$ ssh gpadmin@<gpmaster>
```
Stop the PXF service instances on each segment host. For example:
```
gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster stop
```
Reset the PXF service instances on all Greenplum hosts. For example:
```
gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster reset
```

Note: After you reset PXF, you must initialize and start PXF to use the service again.