ACF2 Command Propagation Facility (CPF) across LPARs

Products

• ACF2 - z/OS

Issue/Introduction

ACF2 propagate changes from one LPAR to the others

Environment

Product: ACF2

Resolution

ACF2 propagates changes across multiple LPARs primarily through the Command Propagation Facility (CPF) 

In a shared environment, propagation works through the following mechanisms:

1. The Communication Layer (CAICCI)

CPF relies on CA Common Communications Interface (CAICCI) to send commands between systems. Each LPAR is defined as a "node" within this network. When a command is issued on one LPAR, CAICCI identifies the target nodes and transmits the request to them 

2. Node and Group Definitions

The systems are organized using specific control records:

• Control(CPF) OPTIONS: Defines the home node and default propagation settings .
• NODEDEF Records: These records define each remote LPAR (node) that should receive updates .
• SYSPLEX Grouping: In environments with shared databases, nodes can be grouped using a SYSPLEX parameter in CCIPARMS. This allows CCI to treat a group of LPARs as a single target, ensuring that an update is sent to the group without creating duplicate updates on the shared disk 

3. Command Execution and Cache Refresh

When a change (such as a password update or a RECKEY command) is issued:

1. The command updates the physical database (if shared).
2. CPF broadcasts the command to the other 6 nodes.
3. Each receiving node executes the command locally to refresh its in-memory caches (e.g., rule buffers), ensuring the change is active immediately across all LPARs without requiring a manual refresh or system restart .

4. Limitations

Please note that not all commands are propagated. For example, administrative commands like SHOW, SET, or DECOMPILE are typically not sent to other nodes as they do not change the security state of the database