We do not use the diadna service.
It has been disabled/deregistered via this command
suexec unicntrl register -D CA-diadna CA-cauwvdmn
Is there any negative impact to completely removeing the directory structure?
rm -rf /opt/CA/SharedComponents/ccs/dia
Can DIA still run if the associated JRE is no longer available?
Can DIA binaries be completely removed?
Would an upgrade fail if the DIA binaries or JRE are not present? (SP7 & SP8)
Release : 11.3.6
Component : CA Workload Automation AE (AutoSys)
1) Can DIA still run if the associated JRE is no longer available?
Answer: DIA has dependency on JRE. So it cannot work without JRE.
2) Can DIA binaries be completely removed?
Answer: Yes, it can be removed completely, but clean uninstall of 11.3.6 common components will fail in future. So at that time, you can copy them back if you want to have clean uninstall of 11.3.6 common components.
3) Would an upgrade fail if the DIA binaries or JRE are not present? (SP7 & SP8)
Answer: AutoSys upgrade has no impact on DIA. 11.3.6 common component upgrade went fine in our testing. So upgrade would not fail if the DIA binaries or JRE are not present. Only uninstall will fail as detailed in answer#2.