IBM Power System POWER7 Series, Optimization And Tuning Manual

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POWER7 and Optimization and Tuning Guide
AIX PKCS11 Library
On systems, the AIX operating system PKCS11 library transparently uses the
on-chip encryption accelerators. For an application using the PKCS11 APIs, no
change or awareness by the application is required. The AIX library interfaces dynamically
decides, based on the algorithm and data size, when to use the accelerators. Because of the
cost of setup and programming of the on-chip accelerators, the advantage is limited to
operations on large blocks of data (tens to hundreds of kilobytes).
4.2 AIX Active System Optimizer and Dynamic System
Optimizer
Workloads are becoming increasingly complex. Typically, they involve a mix of
single-threaded and multi-threaded applications with interactions that are complex and vary
over time. The servers that host these workloads are also continuously evolving to support an
ever-increasing demand for processing capacity and flexibility. Tuning such an environment
for optimal performance is not trivial. It often requires excessive amounts of time and highly
specialized skills. Apart from resources, manual tuning also has the drawback that it is static
in nature, and systems must be retuned when new workloads are introduced or when the
characteristics of existing ones change in time. The Active System Optimizer (ASO) and
Dynamic System Optimizer (DSO) attempt to address the optimization of both the operating
system and server autonomously.
4.2.1 Concepts
DSO is built on the Active System Optimizer (ASO) framework, and expands on two of the
ASO optimization strategies.
Active System Optimizer
DSO is built on the ASO framework that is introduced in AIX V7.1 TL1 SP1. The ASO
framework includes a user-space daemon, advanced instrumentation, and two optimization
strategies. The DSO package extends ASO to provide more optimizations. When the DSO
product is installed and enabled, base ASO features and the extended DSO optimizations are
all activated.
ASO contains a user-level daemon that autonomously tunes the allocation of system
resources to achieve an improvement in system performance. ASO is available on the
POWER7 platform in AIX V7.1 TL1 SP1 (4Q 2011) and AIX V6.1 TL8 SP1 (4Q 2012). DSO
extensions are available in 4Q 2012, and require AIX V7.1 TL2 SP1 or AIX V6.1 TL8 SP1 (on
the POWER7 platform).
The ASO framework works by continuously monitoring and analyzing how current workloads
impact the system, and then using this information to dynamically configure the system to
optimize for current workload requirements.
The ASO framework is transparent, and the administrator is not required to continuously
monitor its operations. In fact, the only required tunable that ASO provides is to turn it on or
off. Once turned on, ASO automatically identifies opportunities to improve performance and
applies the appropriate system changes.