server_picker

SQream DB’s load balancer is called server_picker.

This page serves as a reference for the options and parameters.

Positional command line arguments

$ server_picker [ <Metadata server address> <Metadata server port> [ <TCP listen port> [ <SSL listen port> ] ]
Argument Default Description
Metadata server address   IP or hostname to an active metadata server
Metadata server port   TCP port to an active metadata server
TCP listen port 3108 TCP port for server picker to listen on
Metadata server port 3109 SSL port for server picker to listen on

Starting server picker

Starting temporarily

In general, you should not need to run server_picker manually, but it is sometimes useful for testing.

Assuming we have a metadata server listening on the localhost, on port 3105:

$ nohup server_picker 127.0.0.1 3105 &
$ SP_PID=$!

Using nohup and & sends server picker to run in the background.

Starting temporarily with non-default port

Tell server picker to listen on port 2255 for unsecured connections, and port 2266 for SSL connections.

$ nohup server_picker 127.0.0.1 3105 2255 2266 &
$ SP_PID=$!

Using nohup and & sends server picker to run in the background.

Stopping server picker

$ kill -9 $SP_PID

Tip

It is safe to stop any SQream DB component at any time using kill. No partial data or data corruption should occur when using this method to stop the process.