The Greenplum Streaming Server gpss and gpsscli command line utilities are automatically installed with Greenplum Database version 5.16 and later.

Before you start a GPSS server instance, ensure that you:

• Install and start a compatible Greenplum Database version.
• Can identify the hostname of your master node.
• Can identify the port on which your Greenplum Database master server process is running, if it is not running on the default port (5432).
• Select one or more GPSS host machines that have connectivity to:
  • The GPSS client host systems.
  • The Greenplum Database master and all segment hosts.

If you are using the gpsscli client utility, ensure that you run the command on a host that has connectivity to:

• The client data source host systems. For example, for a Kafka data source, you must have connectivity to each broker host in the Kafka cluster.
• The Greenplum Database master and all segment hosts.

The Greenplum Database and the Greenplum Streaming Server download packages install the GPSS extension. This extension must be registered in each database in which Greenplum users use GPSS to write data to Greenplum tables.

GPSS automatically registers its extension in a database the first time a Greenplum superuser or the database owner initiates a load job. You must manually register the extension in a database if non-privileged Greenplum users will be the first or only users of GPSS in that database.

Perform the following procedure as a Greenplum Database superuser or the database owner to manually register the GPSS extension:

1. Open a new terminal window, log in to the Greenplum Database master host as the gpadmin administrative user, and set up the Greenplum environment. For example:

   $ ssh gpadmin@gpmaster
   gpadmin@gpmaster$ . /usr/local/greenplum-db/greenplum_path.sh

2. Start the psql subsystem, connecting to a database in which you want to register the GPSS formatter function. For example:

   gpmaster$ psql -d testdb

3. Enter the following command to register the extension:

   testdb=# CREATE EXTENSION gpss;

4. Perform steps 2 and 3 for each database in which the Greenplum Streaming Server will write client data.

You configure an invocation of the Greenplum Streaming Server via a JSON-formatted configuration file. This configuration file includes properties that identify the listen address of the GPSS service as well as the gpfdist service host, bind address, and port number. You can specify encryption options in the file, and can also configure whether GPSS reuses external tables.

The contents of a sample GPSS JSON configuration file named gpsscfg1.json follow:

{
    "ListenAddress": {
        "Host": "",
        "Port": 50007,
        "SSL": true
    },
    "Gpfdist": {
        "Host": "",
        "Port": 8319,
        "ReuseTables": false,
        "BindAddress": "127.0.0.1"
    },
    "Certificate": {
        "CertFile": "/home/gpadmin/gpdb_bin/gpdb/server.crt",
        "KeyFile": "/home/gpadmin/gpdb_bin/gpdb/server.key",
        "CAFile": "/home/gpadmin/gpdb_bin/gpdb/rootCA.pem"
    }
}

Refer to the gpss.json reference page for detailed information about the GPSS configuration file format and the configuration properties that the utility supports.

You use the gpss utility to start an instance of the Greenplum Streaming Server on the local host. When you run the command, you provide the name of the configuration file that defines the properties of the GPSS and gpfdist service instances. You can also specify the name of a directory to which gpss writes log files. For example, to start a GPSS instance specifying a log directory named gpsslogs relative to the current working directory:

$ gpss gpsscfg1.json --log-dir ./gpsslogs

The default mode of operation for gpss is to wait for, and then consume, job requests and data from a client. When run in this mode, gpss waits indefinitely. You can interrupt and exit the command with Control-c. You may also choose to run gpss in the background (&). In both cases, gpss writes log and status messages to stdout.

Refer to the gpss reference page for additional information about this command.

If you specify the -l or --log-dir option when you start gpss or run a gpsscli subcommand, GPSS writes log messages to a file in the directory that you specify. If you do not provide this option, GPSS writes log messages to a file in the $HOME/gpAdminLogs directory.

GPSS writes server log messages to a file with the following naming format, where date identifies the date that the log file was created. This date reflects the date that you started the gpss server instance, or the date that the log was rotated for that server instance (see Rotating the GPSS Server Log File below):

gpss_date.log

GPSS writes client log messages to a file with this naming format, where date identifies the date that you ran the command:

gpsscli_date.log

For example, gpss_20181228.log and gpsscli_20181228.log.

After GPSS creates a log file, it appends all server and client log messages written on date to the respective file.

/home/gpadmin/gpAdminLogs/gpss_*.log {
    rotate 5
    weekly
    size 10M
    postrotate
        pkill -SIGUSR2 gpss
    endscript
    compress
}

$ logrotate -s status -d gpss_rotate.conf