The SessionIdManager and the Housekeeper

The SessionIdManager and the Housekeeper
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Default Settings
Configuration

Default Settings

By default, Jetty will instantiate a single instance of the DefaultSessionIdManager and HouseKeeper at startup with default settings.

The default settings are:

DefaultSessionIdManager: worker name: This uniquely identifies the jetty server instance within a cluster. It is set from the value of the JETTY_WORKER_INSTANCE environment variable, or node0 if the environment value is not set. If you have more than one Jetty instance, it is crucial that you explicitly configure the worker name on each Jetty instance (see below for how to configure).
HouseKeeper: scavenge interval: This is the period in seconds between runs of the session scavenger, and by default is set to the equivalent of 10 minutes. As a rule of thumb, you should ensure that the scavenge interval is shorter than the maxInactiveInterval of your sessions to ensure that they are promptly scavenged. See below for instructions on how to configure this.

Configuration

To change the default values, use the module system to enable the sessions module.

This will enable the $jetty.home/etc/sessions/id-manager.xml file and generate a $jetty.base/start.d/sessions.ini file.

The id-manager.xml file instantiates a single DefaultSessionIdManager and HouseKeeper and configures them using the properties from the sessions.ini file.

Edit the ini file to change the properties to easily customize the DefaultSessionIdManager and HouseKeeper:

jetty.sessionIdManager.workerName: By default it is node1. This uniquely identifies the Jetty server instance within a cluster. If you have more than one Jetty instance, it is crucial that you configure the worker name differently on each jetty instance.
jetty.sessionScavengeInterval.seconds: This is the period in seconds between runs of the session scavenger. By default it will run every 600 secs (ie 10 mins). As a rule of thumb, you should ensure that the scavenge interval is shorter than the maxInactiveInterval of your sessions to ensure that they are promptly scavenged.