In the appliance versions of most ArcSight products, there is the ability to set the user session timeout period. Typically this defaults to somewhere between five (5) and 15 minutes – good for a default but incredibly annoying for any real user.  In ArcSight Enterprise Security Manager (ESM), there is no such GUI configuration that allows modification of the user session timeout – so this is what has worked for me:

Set ArcSight Command Center (ACC) timeout greater than 900 seconds (15 minutes) – set to 28800 seconds (8 hours)
vi /opt/arcsight/manager/config/server.properties
service.session.timeout=28800
/sbin/service arcsight_services stop all
/sbin/service arcsight_services start all

Default is 600 seconds = 5 minutes.

In 6.5, 6.5.1 and 6.8 you also need to add the following for the Logger interface in ESM:

vi /opt/arcsight/logger/userdata/logger/user/logger/logger.properties
server.search.timeout=28800
/sbin/service arcsight_services stop all
/sbin/service arcsight_services start all

Default is 600 seconds = 5 minutes.

Yes, eight (8) hours may seem like a long time, so chose what is appropriate for your site.  🙂