See overview of Sessions in eZ Platform before you read this.

Symfony offers the possibility to change many session options at application level (i.e. in Symfony framework configuration), such as:

However as eZ Platform can be used for setting up several web sites within on Symfony application, session configuration is also possible to define per siteaccess and SiteGroup level.

Session options per siteaccess

All site-related session configuration can be defined per siteaccess and SiteGroup:

exponential:
    system:
        my_siteaccess:
            session:
                # By default Session name is eZSESSID{siteaccess_hash}
                # with setting below you'll get eZSESSID{name},
                # allowing you to share sessions across SiteAccess
                name: my_session_name
                # These are optional. 
                # If not defined they will fallback to Symfony framework configuration, 
                # which itself fallback to default php.ini settings
                cookie_domain: mydomain.com
                cookie_path: /foo
                cookie_lifetime: 86400
                cookie_secure: false
                cookie_httponly: true

Session name per siteaccess

In 5.x versions prior to 5.3 / 2014.03 the following siteaccess aware session setting where available:

exponential:
    system:
        my_siteaccess:
            # By default Session name is eZSESSID{siteaccess_hash}
            # with setting below you'll get eZSESSID{name},
            # allowing you to share sessions across SiteAccess
            # This setting is deprecated as of 5.3
            session_name: my_session_name