01-11-2012, 04:56 PM
Autonomic computing:
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Introduction
Autonomic computing:
The term autonomic is derived from human biology. The autonomic nervous system monitors your heartbeat, checks your blood sugar level and keeps your body temperature close to 98.6°F without any conscious effort on your part. In much the same way, autonomic computing capabilities anticipate IT system requirements and resolve problems, with minimal human intervention. As a result, IT professionals can focus on tasks with higher value to the business. Autonomic computing manages technology by using technology.
Autonomic computing is a computing environment with the ability to manage itself and dynamically adapt to change in accordance with business policies and objectives. Self-managing envi¬ronments can perform such activities based on situations they observe or sense in the IT environment rather than requiring IT professionals to initiate the task. These environments are self-configuring, self-healing, self-optimizing, and self-protecting.
Autonomic Artifacts
It is assumed that an autonomic computing system is made up of a connected set of autonomic elements. Each element must include sensors and effectors. Monitoring behavior through the sensors, comparing this with expectations, deciding what action, if any, is needed and then executing that action through effectors, creates a control loop (Figure 2).
Reflexes and Healing
A concept inspired by biological systems is the duel approach of reflexes and healing. Animals have a reflex system, where the nerve pathways enable rapid response to pain. Reflexes cause a rapid, involuntary motion, such as when a hot surface is touched. The effect is that the system reconfigures itself, moving away from the danger to keep the component functioning. On a much longer timescale, the body will heal itself. Resources from one part of the system are redirected to rebuild the injured body part, including repair of the reflex response network.
While this cannot help in the real-time response, directly after an event, it can prepare the system for the next event. In addition, it can readjust the system for operation with a reduced set of resources
NASA’S BEACON MONITOR
NASA has shown a growing interest in adaptive operations and onboard autonomy. NASA missions, particularly those to deep space, are considering autonomic decision making to avoid the unacceptable lag time between a craft encountering new situations and the round-trip delay in obtaining guidance from mission control. Two of the first notable missions to use autonomy are DS1 (Deep Space 1) and the Mars Pathfinder. One of the interesting outcomes from the DS1 mission work was the beacon monitor concept. With beacon monitoring, the spacecraft sends a signal to the ground that indicates how urgent it is to track the spacecraft for telemetry. This concept involved a paradigm shift for NASA from routine telemetry
Conclusion
Autonomic computing is an emerging holistic approach to computer system development that aims to bring a new level of automation and dependability to systems through self-healing, self-optimizing, self-configuring and self-protection functions.
The promotion of autonomic computing will be assisted by good examples of its use. An important step is that direction is the establishment of design patterns for such systems.
This paper has presented a general design template based on a simple characterization of autonomic systems, incorporating ideas from related research areas. This involves internal and external monitoring, and consequential adjustment to improve system operation. The notion of a pulse monitor is used to provide a simple means of observing the ‘health’ of each autonomic element. A demonstration system to illustrate and further refine this architecture us currently under development.