HAWQ Client Applications

Alternatively, you may want to provide access to your HAWQ master node from a Linux client outside of your HAWQ cluster. One option to enable this access is to install the full HAWQ binary on the client node. A second option is to create a minimal client package from an existing HAWQ installation which you could then install on a non-HAWQ client. Refer to HAWQ psql Client Package for instructions on creating, installing, and running such a package.

HAWQ is installed with a number of client utility applications. These applications are located in the $GPHOME/bin directory of your HAWQ master host installation. The following client utility applications are the most commonly used:

When using these client applications, you must connect to a database through the HAWQ master instance. You will need to know the name of your target database, the host name and port number of the master, and what database user name to connect as. This information can be provided on the command-line using the options -d, -h, -p, and -U respectively. If an argument is found that does not belong to any option, it will be interpreted as the database name first.

All of these options have default values which will be used if the option is not specified. The default host is the local host. The default port number is 5432. The default user name is your OS system user name, as is the default database name. Note that OS user names and HAWQ user names are not necessarily the same.

If the default values are not correct, you can set the environment variables PGDATABASE, PGHOST, PGPORT, and PGUSER to the appropriate values, or use a file to contain frequently-used passwords.

HAWQ psql Client Package

You may choose to provide psql access to your HAWQ master node from a non-HAWQ Linux client. This section describes the procedures for creating, installing, and running a minimal HAWQ psql client package.

Perform the following steps to create a HAWQ Linux psql client package:

Log in to a HAWQ node and set up your HAWQ environment:

Note: You can create the client package on any node on which HAWQ is installed.

gpadmin@hawq-node$ mkdir hawqclient
gpadmin@hawq-node$ cd hawqclient
gpadmin@hawq-node$ export HAWQCLIENTWORKDIR=`pwd`
gpadmin@hawq-node$ mkdir bin

Copy the HAWQ psql client binary and libraries to the appropriate work directories:

gpadmin@hawq-node$ cp $GPHOME/bin/psql $HAWQCLIENTWORKDIR/bin/
gpadmin@hawq-node$ cp -d $GPHOME/lib/libpq.* $HAWQCLIENTWORKDIR/lib/

Generate a runtime environment file for the HAWQ client package:
```
gpadmin@hawq-node$ echo 'HAWQ_CLIENT=`pwd`
export PATH=$HAWQ_CLIENT/bin:$PATH
export LD_LIBRARY_PATH=$HAWQ_CLIENT/lib:$LD_LIBRARY_PATH' > ./hawq_client_env.sh
```
The hawq_client_env.sh file sets $PATH and $LD_LIBRARY_PATH appropriately for a HAWQ client runtime environment.
Tar and compress the HAWQ client package:

These commands create a hawqclient.tar.gz file in the current directory.

Perform the following procedure to install the HAWQ client package you created in the previous section on a like Linux-based system:

Log in to the client system and create or navigate to the directory in which you want to install the HAWQ client:
```
$ ssh <user>@<client>
user@client$ cd <install-dir>
```
Make note of the base HAWQ client install directory, you will need this path to run the client.
Add the HAWQ client install directory setting to your .bash_profile or similar shell login script:
```
export HAWQCLIENTINSTDIR=<install-dir>
```
Copy the HAWQ client package you created previously to the client system:
```
user@client$ scp gpadmin@hawq-node:/<dir>/hawqclient.tar.gz .
```
Extract the package:

This command extracts the HAWQ client to ./hawqclient.
Clean up:
```
user@client$ rm hawqclient.tar.gz
```

Perform the following procedure to run a previously-installed HAWQ psql client package.

Note: If you have enabled Kerberos user authentication for HAWQ, refer to Kerberos Considerations for Non-HAWQ Clients for additional client configuration requirements.

Source the HAWQ client environment file (recall the HAWQ client install directory you noted in the previous section):
```
user@client$ . $HAWQCLIENTINSTDIR/hawqclient/hawq_client_env.sh
```
hawq_client_env.sh sets up the HAWQ client runtime environment, including setting your $PATH and $LD_LIBRARY_PATH to locate the psql client binaries and libraries.
Edit your .bash_profile or other shell initialization file to source hawq_client_env.sh on login. For example, add:
```
. $HAWQCLIENTINSTDIR/hawqclient/hawq_client_env.sh
```