Server Picker

SQreamDB’s load balancer is called server_picker.

Command Line Arguments

Parameters

Argument	Default	Description
`--metadata_server_port`	`3105`	The metadata server listening port
`--metadata_server_ip`	`127.0.0.1`	The metadata server IP
`--port`	`3108`	The server picker port
`--ssl_port`	`3109`	The server picker ssl port
`--log4_config`	`/home/sqream/sqream3/etc/server_picker_log_properties`	The server picker log4 configuration file to use
`--refresh_interval`	`15`	Refresh interval time to check available nodes
`--services`	None	Lists services separated by comma
`--help`	None	Used to display a help message or documentation for a particular program or command
`--log_path`	`./server_picker_logs`	Configures the default location for the log file

Example

server_picker --metadata_server_ip=127.0.0.1 --metadata_server_port=3105 --port=3118 --ssl_port=3119 --services=sqream23,sqream0 --log4_config=/home/sqream/metadata_log_properties --refresh_interval=10

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 --metadata_server_ip=127.0.0.1 metadata_server_port=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 --metadata_server_ip=127.0.0.1 --metadata_server_port=3105 --port=2255 --ssl_port=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.