Session Management Overview

Session managers save the current state of open audio applications along with their connections, allowing sessions to be easily restored without having to manually open each application, load individual settings files, and reconnect all JACK connections.

There are several session managers available for Linux. However, not all applications are compatible with all session managers, though some managers do provide limited support for apps not designed to work with that particular session manager.

This is a brief synopsis of the most well-known session managers available for Linux.

lash

JACK Session

• Fully compatible with JACK apps that have built-in support for LADISH, JACK Session or LASH
• Not compatible with apps that only support Non Session Manager
• Limited compatibility with apps without session manager support:
  • Some apps are programmed to save their current state when they receive the “SIGUSR1” Unix signal, and LADISH is able to send this signal to such apps. On receiving this signal, apps may then open a save file dialogue or save their state to a default file location. The user may need to load this state file manually after a session is restored
  • For apps which do not respond to the SIGUSR1 signal, LADISH is only able to restore their JACK connections
• GUI frontend: Gladish, Claudia
• Saving a session will save the state of all apps (except for those that cannot be prompted, one way or another, to save their state) plus the JACK connections of ALL apps
• Opening a session will automatically launch all apps, restoring their state (if possible) plus their JACK connections
• Apps which support LADISH, JACK Session or LASH can be told to save/load their state to/from a specific location
• First released in 2009. Currently in active development

• Supported apps: http://apps.linuxaudio.org/apps/all/ladish
• Website: http://ladish.org/
• Manual: http://ladish.org/wiki/tutorial

Non Session Manager

There are other session managers available for Linux. aj-snapshot is a command-line tool and background service which can serve as the foundation for a complete semi-manual session management system. One such implementation is documented here. Another command-line session manager framework is Chino.

A selection of links providing further information about Linux audio session management.

Linux Weekly News: A Brief Survey of Linux Audio Session Managers by Dave Philips (January 2013)

The Penguin Producer: The LADI Session Handler

Tango Studio: LADISH

Nedko Arnaudov: LADISH Creator's Blog

Tango Studio: Jack Session