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 |