cfginitstart_pxf.html.md.erb

---
title: Starting, Stopping, and Restarting PXF
---

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PXF provides two management commands:

- `pxf cluster` - manage all PXF service instances in the Greenplum Database cluster
- `pxf` - manage the PXF service instance on a specific Greenplum Database host

The [`pxf cluster`](ref/pxf-cluster.html) command supports `init`, `start`, `status`, `stop`, and `sync` subcommands. When you run a `pxf cluster` subcommand on the Greenplum Database master host, you perform the operation on all segment hosts in the Greenplum Database cluster. PXF also runs the `init` and `sync` commands on the standby master host.

The [`pxf`](ref/pxf.html) command supports `init`, `start`, `stop`, `restart`, and `status` operations. These operations run locally. That is, if you want to start or stop the PXF agent on a specific Greenplum Database segment host, you log in to the host and run the command. 


## <a id="start_pxf"></a>Starting PXF

After initializing PXF, you must start PXF on each segment host in your Greenplum Database cluster. The PXF service, once started, runs as the `gpadmin` user on default port 5888. Only the `gpadmin` user can start and stop the PXF service.

If you want to change the default PXF configuration, you must update the configuration before you start PXF.

`$PXF_CONF/conf` includes these user-customizable configuration files:

- `pxf-env.sh` - runtime configuration parameters
- `pxf-log4j.properties` - logging configuration parameters
- `pxf-profiles.xml` - custom profile definitions

The `pxf-env.sh` file exposes the following PXF runtime configuration parameters:

| Parameter  | Description | Default Value |
|-----------|---------------| ------------|
| JAVA_HOME    | The Java JRE home directory. | /usr/java/default |
| PXF_LOGDIR   | The PXF log directory. | $PXF_CONF/logs |
| PXF_JVM_OPTS  | Default options for the PXF Java virtual machine. | -Xmx2g -Xms1g |
| PXF_KEYTAB  | The absolute path to the PXF service Kerberos principal keytab file. | $PXF_CONF/keytabs/pxf.service.keytab |
| PXF_PRINCIPAL  | The PXF service Kerberos principal. | gpadmin/\_HOST@EXAMPLE.COM |

You must synchronize any changes that you make to `pxf-env.sh`, `pxf-log4j.properties`, or `pxf-profiles.xml` to the Greenplum Database cluster, and (re)start PXF on each segment host.

### <a id="start_pxf_prereq" class="no-quick-link"></a>Prerequisites

Before you start PXF in your Greenplum Database cluster, ensure that:

- Your Greenplum Database cluster is up and running.
- You have previously initialized PXF.
 
### <a id="start_pxf_proc" class="no-quick-link"></a>Procedure

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

1. Log in to the Greenplum Database master node:

    ``` shell
    $ ssh gpadmin@<gpmaster>
    ```

3. Run the `pxf cluster start` command to start PXF on each segment host. For example:

    ```shell
    gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster start
    ```

## <a id="stop_pxf"></a>Stopping PXF

If you must stop PXF, for example if you are upgrading PXF, you must stop PXF on each segment host in your Greenplum Database cluster. Only the `gpadmin` user can stop the PXF service.

### <a id="stop_pxf_prereq" class="no-quick-link"></a>Prerequisites

Before you stop PXF in your Greenplum Database cluster, ensure that your Greenplum Database cluster is up and running.
 
### <a id="stop_pxf_proc" class="no-quick-link"></a>Procedure

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

1. Log in to the Greenplum Database master node:

    ``` shell
    $ ssh gpadmin@<gpmaster>
    ```

3. Run the `pxf cluster stop` command to stop PXF on each segment host. For example:

    ```shell
    gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster stop
    ```

## <a id="restart_pxf"></a>Restarting PXF

If you must restart PXF, for example if you updated PXF user configuration files in `$PXF_CONF/conf`, you can stop, and then start, PXF in your Greenplum Database cluster.

Only the `gpadmin` user can restart the PXF service.

### <a id="restart_pxf_prereq" class="no-quick-link"></a>Prerequisites

Before you restart PXF in your Greenplum Database cluster, ensure that your Greenplum Database cluster is up and running.
 
### <a id="restart_pxf_proc" class="no-quick-link"></a>Procedure

Perform the following procedure to restart PXF in your Greenplum Database cluster.

1. Log in to the Greenplum Database master node:

    ``` shell
    $ ssh gpadmin@<gpmaster>
    ```

2. Restart PXF:

    ```shell
    gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster stop
    gpadmin@gpmaster$ $GPHOME/pxf/bin/pxf cluster start
    ```