– Benefit/Value: GLYPH<129> Db2 locking receives performance similar to simplex operations GLYPH<129> Reduces CPU and CF link overhead GLYPH<129> Avoids the overhead of synchronous protocol handshakes on every update GLYPH<129> Duplexing failover much fa ster than log-based recovery – Targeted at multi-site clients who run split workloads at distance to make duplexing  lock structures at distance practical. GLYPH<SM590000> CF Processor Scalability: – CF work management and dispatcher changes to allow improved efficiency as  processors are added to scale up the capacity of a CF image. – Functionally specialized ICF processors that operate for CF images having more than  a threshold number of dedicated processors defined for them: GLYPH<129> One functionally specialized processor for inspecting suspended commands.  GLYPH<129> One functionally specialized processor for pulling in new commands. GLYPH<129> The remaining processors are non-specialized for general CF request processing. – Avoids many inter-processor contentions that were associated with CF dispatching GLYPH<SM590000> Enable systems management applications to collect valid CF LPAR information through  z/OS BCPii: – System Type (CFCC) – System Level (CFCC LEVEL) – Dynamic Dispatch settings to indicate CF state (dedicated, shared, and Thin Interrupt),  which are useful when investigating functional performance problems To support an upgrade from one CFCC level to the next, different levels of CFCC can be run  concurrently while the CF LPARs are running on different servers. CF LPARs that run on the  same server share the CFCC level. z15 servers (CFCC level 24) can coexist in a sysplex with CFCC levels 23, 22, 21, and 20. The CFCC is implemented by using the active wait technique. This technique means that the  CFCC is always running (processing or searching for service) and never enters a wait state.  Therefore, the CF Control Code uses all the processor capacity that are available for the CF  LPAR.  If the LPAR that is running the CFCC includes only dedicated processors (CPs or ICFs), the  use of all processor capacity (cycles) is not an issue. However, this configuration can be an  issue if the LPAR that is running the CFCC includes shared processors. We suggest that you  enable thin interrupts on the CF LPAR (Default for z15).  Performance consideration:  Dedicated processor CF still provides the best CF image  performance for production environments. CF structure sizing changes are expected when moving to CFCC Level 24. Always review the  CF structure size by using the  CFSizer tool when changing CFCC levels. For more information about the recommended CFCC levels, see the  current exception letter  that is published on IBM Resource Linkfi . 148  IBM z15 (8561) Technical Guide