Sections 24.3.9 & 24.3.10 are 2 ways of setting session externalization to DG.  However 24.3.10 is the old way prior to 7.2 using remote store. Setting session externalization using hotrod-store described in section 24.3.9 is the recommended way. As it is 24.3.9. Externalize HTTP Sessions to Red Hat Data Grid  title is generic and confusing. 

It should be

"24.3.9. Externalize HTTP Sessions to Red Hat Data Grid using a Hotrod store" 

to distinguish with 24.3.10