KDE PIM/Akonadi/Multi-Instance

Akonadi Multi-Instance Setup

The multi-instance akonadi setup allows to run multiple akonadi-servers in parallel, using the same posix-user. DBus service names are postfixed with an instance identifier, so multiple instances can run on the same DBus. Also all relevant configuration files/direcories are either postfixed or put in a separate directory, to avoid any clashes, making it safe to run multiple instances in parallel.

The behavior of a normal akonadi instance is not changed.

To run multiple akonadi instances in parallel it is required to assign to each instance a unique identifier using:

akonadictl --instance IDENTIFIER start

An application will the connect to a server depending on the AKONADI_INSTANCE environment variable (set to IDENTIFIER).

You can run a normal akonadi instance (without --instance) in parallel with multi-instance akonadi instances.

Each instance will run it's own mysql server.

Usage

start instance:

export AKONADI_DISABLE_AGENT_AUTOSTART
akonadictl --instance IDENTIFIER start

connect akonadiconsole:

export AKONADI_INSTANCE=IDENTIFIER
akonadiconsole

stop instance:

akonadictl --instance IDENTIFIER stop

Directories

The multi-instance setup puts it's files in the following directories:

• .config/akonadi/instance/$IDENTIFIER
• .local/share/akonadi/instance/$IDENTIFIER
• .kde4/share/config/akonadi/akonadi_imap_resource_0_$IDENTIFIERrc

To cleanup an instance, just delete all the directories and configs above.

Akonadiconsole

To connect to an instance using akonadiconsole export the following environment variable first (with inst1 being the instance identifier):

export AKONADI_INSTANCE=inst1

A couple of features, such as the debugging facilities or the mysql console do not work, but managing agents and browsing the collection tree should work just fine. Note that you might get an error message on startup that your mysql database socket couldn't be found, this is safe to ignore.

You can connect to the mysql instance directly using the mysql console (standalone, not the akonadiconsole one):

mysql --protocol=SOCKET --socket=.local/share/akonadi/instance/inst1/socket-myhost2/mysql.socket

Missing Features

• Debugging facilities as mentioned above
• Firstrun: Is disabled in servermanager.cpp, otherwise the firstrun code will crash (an assert prevents running the code since it is unsafe so far).
• It is not safe to run a multi-instance setup without exporting AKONADI_DISABLE_AGENT_AUTOSTART first, because the default setup desktop files contain configs with hardcoded paths, which would result in every akonadi instance creating a resource for the same default path.

Development

In order to make akonadi code work in the multi-instance setup all unique identifiers need to be made distinguishable between instances. That includes most prominently:

• dbus service names
• configfile names
• default directory paths

You only need to change these, if you add/use dbus interfaces, or access configfiles directly. Most things have already been taken care of using the agentbase/resourcebase classes.

• kdepimlibs/akonadi/servermanager.h contains a couple of helper functions to help with that.

Note that it is not possible to change the dbus names or the prefixed directories just in kdepimlibs, as the akonadi-server makes assumptions on where to find the directories and dbus-services.