Adabas Parallel Services is very similar to another Adabas add-on product, Adabas Cluster Services. As shown in the following table, the differences between the two are the mechanisms used for inter-nucleus communication and for maintaining and accessing the shared cache and lock data:

Service	Adabas Parallel Services	Adabas Cluster Services
Architecture	all nuclei on same system image	nuclei on different system images in parallel sysplex (z/OS only)
Communication (inter-nucleus)	via inter-process communication (ADALNK)	via cross-system coupling (XCF) services
Cache	in shared data space or 64-bit addressable virtual storage	in coupling facility
Lock	in shared data space	in coupling facility