<s>
Autonomic	B-Architecture
computing	I-Architecture
(	O
AC	O
)	O
is	O
distributed	B-Architecture
computing	I-Architecture
resources	O
with	O
self-managing	B-General_Concept
characteristics	O
,	O
adapting	O
to	O
unpredictable	O
changes	O
while	O
hiding	O
intrinsic	O
complexity	O
to	O
operators	O
and	O
users	O
.	O
</s>
<s>
Initiated	O
by	O
IBM	O
in	O
2001	O
,	O
this	O
initiative	O
ultimately	O
aimed	O
to	O
develop	O
computer	O
systems	O
capable	O
of	O
self-management	B-General_Concept
,	O
to	O
overcome	O
the	O
rapidly	O
growing	O
complexity	O
of	O
computing	O
systems	B-Application
management	I-Application
,	O
and	O
to	O
reduce	O
the	O
barrier	O
that	O
complexity	O
poses	O
to	O
further	O
growth	O
.	O
</s>
<s>
An	O
autonomic	B-Architecture
computing	I-Architecture
framework	O
is	O
composed	O
of	O
autonomic	O
components	O
(	O
AC	O
)	O
interacting	O
with	O
each	O
other	O
.	O
</s>
<s>
An	O
AC	O
can	O
be	O
modeled	O
in	O
terms	O
of	O
two	O
main	O
control	O
schemes	O
(	O
local	O
and	O
global	O
)	O
with	O
sensors	O
(	O
for	O
self-monitoring	O
)	O
,	O
effectors	B-Algorithm
(	O
for	O
self-adjustment	O
)	O
,	O
knowledge	O
and	O
planner/adapter	O
for	O
exploiting	O
policies	O
based	O
on	O
self	O
-	O
and	O
environment	O
awareness	O
.	O
</s>
<s>
However	O
,	O
most	O
of	O
these	O
approaches	O
are	O
typically	O
conceived	O
with	O
centralized	O
or	O
cluster-based	O
server	B-Application
architectures	O
in	O
mind	O
and	O
mostly	O
address	O
the	O
need	O
of	O
reducing	O
management	O
costs	O
rather	O
than	O
the	O
need	O
of	O
enabling	O
complex	O
software	O
systems	O
or	O
providing	O
innovative	O
services	O
.	O
</s>
<s>
Some	O
autonomic	B-Architecture
systems	I-Architecture
involve	O
mobile	O
agents	O
interacting	O
via	O
loosely	O
coupled	O
communication	O
mechanisms	O
.	O
</s>
<s>
Autonomy-oriented	B-Architecture
computation	I-Architecture
is	O
a	O
paradigm	O
proposed	O
by	O
Jiming	O
Liu	O
in	O
2001	O
that	O
uses	O
artificial	O
systems	O
imitating	O
social	O
animals	O
 '	O
collective	O
behaviours	O
to	O
solve	O
difficult	O
computational	O
problems	O
.	O
</s>
<s>
For	O
example	O
,	O
ant	B-Algorithm
colony	I-Algorithm
optimization	I-Algorithm
could	O
be	O
studied	O
in	O
this	O
paradigm	O
.	O
</s>
<s>
warn	O
that	O
the	O
dream	O
of	O
interconnectivity	O
of	O
computing	O
systems	O
and	O
devices	O
could	O
become	O
the	O
"	O
nightmare	O
of	O
pervasive	B-Architecture
computing	I-Architecture
"	O
in	O
which	O
architects	O
are	O
unable	O
to	O
anticipate	O
,	O
design	O
and	O
maintain	O
the	O
complexity	O
of	O
interactions	O
.	O
</s>
<s>
They	O
state	O
the	O
essence	O
of	O
autonomic	B-Architecture
computing	I-Architecture
is	O
system	O
self-management	B-General_Concept
,	O
freeing	O
administrators	O
from	O
low-level	O
task	O
management	O
while	O
delivering	O
better	O
system	O
behavior	O
.	O
</s>
<s>
A	O
general	O
problem	O
of	O
modern	O
distributed	B-Architecture
computing	I-Architecture
systems	I-Architecture
is	O
that	O
their	O
complexity	O
,	O
and	O
in	O
particular	O
the	O
complexity	O
of	O
their	O
management	O
,	O
is	O
becoming	O
a	O
significant	O
limiting	O
factor	O
in	O
their	O
further	O
development	O
.	O
</s>
<s>
Large	O
companies	O
and	O
institutions	O
are	O
employing	O
large-scale	O
computer	B-Architecture
networks	I-Architecture
for	O
communication	O
and	O
computation	O
.	O
</s>
<s>
The	O
distributed	B-Architecture
applications	I-Architecture
running	O
on	O
these	O
computer	B-Architecture
networks	I-Architecture
are	O
diverse	O
and	O
deal	O
with	O
many	O
tasks	O
,	O
ranging	O
from	O
internal	O
control	O
processes	O
to	O
presenting	O
web	O
content	O
to	O
customer	O
support	O
.	O
</s>
<s>
They	O
do	O
so	O
by	O
using	O
laptops	B-Device
,	O
personal	B-Application
digital	I-Application
assistants	I-Application
,	O
or	O
mobile	O
phones	O
with	O
diverse	O
forms	O
of	O
wireless	O
technologies	O
to	O
access	O
their	O
companies	O
 '	O
data	O
.	O
</s>
<s>
This	O
creates	O
an	O
enormous	O
complexity	O
in	O
the	O
overall	O
computer	B-Architecture
network	I-Architecture
which	O
is	O
hard	O
to	O
control	O
manually	O
by	O
human	O
operators	O
.	O
</s>
<s>
Most	O
'	O
autonomic	O
 '	O
service	O
providers	O
guarantee	O
only	O
up	O
to	O
the	O
basic	O
plumbing	O
layer	O
(	O
power	O
,	O
hardware	O
,	O
operating	B-General_Concept
system	I-General_Concept
,	O
network	O
and	O
basic	O
database	O
parameters	O
)	O
.	O
</s>
<s>
The	O
Autonomic	B-Architecture
Computing	I-Architecture
Initiative	O
(	O
ACI	O
)	O
aims	O
at	O
providing	O
the	O
foundation	O
for	O
autonomic	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
In	O
a	O
self-managing	B-General_Concept
autonomic	B-Architecture
system	I-Architecture
,	O
the	O
human	O
operator	O
takes	O
on	O
a	O
new	O
role	O
:	O
instead	O
of	O
controlling	O
the	O
system	O
directly	O
,	O
he/she	O
defines	O
general	O
policies	O
and	O
rules	O
that	O
guide	O
the	O
self-management	B-General_Concept
process	O
.	O
</s>
<s>
Self-healing	B-General_Concept
:	O
Automatic	O
discovery	O
,	O
and	O
correction	O
of	O
faults	O
;	O
</s>
<s>
Self-learning	O
:	O
Systems	O
use	O
machine	O
learning	O
techniques	O
such	O
as	O
unsupervised	B-General_Concept
learning	I-General_Concept
which	O
does	O
not	O
require	O
external	O
control	O
;	O
</s>
<s>
Self-management	B-General_Concept
(	O
also	O
called	O
self-governance	O
)	O
:	O
A	O
system	O
that	O
manages	O
itself	O
without	O
external	O
intervention	O
.	O
</s>
<s>
Self	O
-management	O
also	O
refers	O
to	O
a	O
set	O
of	O
self-star	O
processes	O
such	O
as	O
autonomic	B-Architecture
computing	I-Architecture
rather	O
than	O
a	O
single	O
self-star	O
process	O
;	O
</s>
<s>
IBM	O
has	O
set	O
forth	O
eight	O
conditions	O
that	O
define	O
an	O
autonomic	B-Architecture
system	I-Architecture
:	O
</s>
<s>
Even	O
though	O
the	O
purpose	O
and	O
thus	O
the	O
behaviour	O
of	O
autonomic	B-Architecture
systems	I-Architecture
vary	O
from	O
system	O
to	O
system	O
,	O
every	O
autonomic	B-Architecture
system	I-Architecture
should	O
be	O
able	O
to	O
exhibit	O
a	O
minimum	O
set	O
of	O
properties	O
to	O
achieve	O
its	O
purpose	O
:	O
</s>
<s>
As	O
such	O
,	O
an	O
autonomic	B-Architecture
system	I-Architecture
must	O
be	O
self-contained	O
and	O
able	O
to	O
start-up	O
and	O
operate	O
without	O
any	O
manual	O
intervention	O
or	O
external	O
help	O
.	O
</s>
<s>
Adaptive	O
:	O
An	O
autonomic	B-Architecture
system	I-Architecture
must	O
be	O
able	O
to	O
change	O
its	O
operation	O
(	O
i.e.	O
,	O
its	O
configuration	O
,	O
state	O
and	O
functions	O
)	O
.	O
</s>
<s>
Aware	O
:	O
An	O
autonomic	B-Architecture
system	I-Architecture
must	O
be	O
able	O
to	O
monitor	O
(	O
sense	O
)	O
its	O
operational	O
context	O
as	O
well	O
as	O
its	O
internal	O
state	O
in	O
order	O
to	O
be	O
able	O
to	O
assess	O
if	O
its	O
current	O
operation	O
serves	O
its	O
purpose	O
.	O
</s>
<s>
IBM	O
defined	O
five	O
evolutionary	O
levels	O
,	O
or	O
the	O
autonomic	O
deployment	O
model	O
,	O
for	O
the	O
deployment	O
of	O
autonomic	B-Architecture
systems	I-Architecture
:	O
</s>
<s>
level	O
5	O
represents	O
the	O
ultimate	O
goal	O
of	O
autonomic	O
,	O
self-managing	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
The	O
design	O
complexity	O
of	O
Autonomic	B-Architecture
Systems	I-Architecture
can	O
be	O
simplified	O
by	O
utilizing	O
design	O
patterns	O
such	O
as	O
the	O
model	O
–	O
view	O
–	O
controller	O
(	O
MVC	O
)	O
pattern	O
to	O
improve	O
concern	O
separation	O
by	O
encapsulating	B-Application
functional	O
concerns	O
.	O
</s>
<s>
A	O
basic	O
concept	O
that	O
will	O
be	O
applied	O
in	O
Autonomic	B-Architecture
Systems	I-Architecture
are	O
closed	O
control	O
loops	O
.	O
</s>
<s>
Essentially	O
,	O
a	O
closed	O
control	O
loop	O
in	O
a	O
self-managing	B-General_Concept
system	O
monitors	O
some	O
resource	O
(	O
software	O
or	O
hardware	O
component	O
)	O
and	O
autonomously	O
tries	O
to	O
keep	O
its	O
parameters	O
within	O
a	O
desired	O
range	O
.	O
</s>
<s>
According	O
to	O
IBM	O
,	O
hundreds	O
or	O
even	O
thousands	O
of	O
these	O
control	O
loops	O
are	O
expected	O
to	O
work	O
in	O
a	O
large-scale	O
self-managing	B-General_Concept
computer	O
system	O
.	O
</s>
<s>
A	O
fundamental	O
building	O
block	O
of	O
an	O
autonomic	B-Architecture
system	I-Architecture
is	O
the	O
sensing	O
capability	O
(	O
Sensors	O
Si	O
)	O
,	O
which	O
enables	O
the	O
system	O
to	O
observe	O
its	O
external	O
operational	O
context	O
.	O
</s>
<s>
Inherent	O
to	O
an	O
autonomic	B-Architecture
system	I-Architecture
is	O
the	O
knowledge	O
of	O
the	O
Purpose	O
(	O
intention	O
)	O
and	O
the	O
Know-how	O
to	O
operate	O
itself	O
(	O
e.g.	O
,	O
bootstrapping	O
,	O
configuration	O
knowledge	O
,	O
interpretation	O
of	O
sensory	O
data	O
,	O
etc	O
.	O
)	O
</s>
<s>
The	O
actual	O
operation	O
of	O
the	O
autonomic	B-Architecture
system	I-Architecture
is	O
dictated	O
by	O
the	O
Logic	O
,	O
which	O
is	O
responsible	O
for	O
making	O
the	O
right	O
decisions	O
to	O
serve	O
its	O
Purpose	O
,	O
and	O
influence	O
by	O
the	O
observation	O
of	O
the	O
operational	O
context	O
(	O
based	O
on	O
the	O
sensor	O
input	O
)	O
.	O
</s>
<s>
This	O
model	O
highlights	O
the	O
fact	O
that	O
the	O
operation	O
of	O
an	O
autonomic	B-Architecture
system	I-Architecture
is	O
purpose-driven	O
.	O
</s>
<s>
If	O
seen	O
as	O
a	O
control	O
system	O
this	O
would	O
be	O
encoded	O
as	O
a	O
feedback	O
error	O
function	O
or	O
in	O
a	O
heuristically	O
assisted	O
system	O
as	O
an	O
algorithm	O
combined	O
with	O
set	O
of	O
heuristics	B-Algorithm
bounding	O
its	O
operational	O
space	O
.	O
</s>
