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Softw
are
Arc
hitectu
re
Pen
n S
tate
Harr
isburg
CO
MP
413
W
Fall
200
7
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
One D
efinitio
n
•S
oft
wa
re a
rch
ite
ctu
re is t
he
fu
nd
am
en
tal
org
an
iza
tio
n o
f a
syste
m,
em
bo
die
d in
:
–T
he
com
po
ne
nts
of th
e s
yste
m
–R
ela
tio
nsh
ips a
mo
ng
th
e c
om
po
ne
nts
–R
ela
tio
nsh
ips b
etw
ee
n th
e c
om
po
nen
ts a
nd
the
en
viron
me
nt
–P
rin
cip
les g
ove
rnin
g th
e d
esig
n a
nd
evo
lutio
n
of th
e s
yste
m.
AN
SI/IE
EE
Std
1471-2
000, R
ecom
mended
Pra
ctice for
Arc
hitectu
ral D
escription o
f S
oftw
are
-In
tensiv
e S
yste
ms
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
A S
imple
r D
efinitio
n
•T
he s
oftw
are
arc
hitectu
re o
f a p
rogra
m
or
com
puting s
yste
m is:
–T
he
so
ftw
are
str
uctu
res o
f th
e s
yste
m
–T
he
re
latio
nsh
ips a
mo
ng
th
e s
tru
ctu
res a
nd
–T
he
ir e
xte
rna
lly v
isib
le b
eh
avio
rs.
Softw
are
Arc
hitectu
re In P
ractice 2
/eby L
en B
ass,
Paul C
lem
ents
, and R
ick K
azm
an
Addis
on-W
esle
y
2007.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
A S
imple
r D
efinitio
n
•N
ote
th
at:
–T
he
so
ftw
are
str
uctu
res o
f th
e s
yste
m
–T
he
re
latio
nsh
ips a
mo
ng
th
e s
tru
ctu
res a
nd
–T
he
ir e
xte
rna
lly v
isib
le b
eh
avio
rs.
•Im
plie
s b
oth
sta
tic a
nd
dyn
am
ic m
od
els
are
at
pla
y.
•T
he
arc
hite
ctu
ral de
scri
ptio
n o
f a
syste
m
mu
st
take in
to a
ccou
nt
mu
ltip
le d
iffe
rin
g
vie
wp
oin
ts.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W5
Arc
hitectu
re Im
port
ance
•S
yste
m a
rchitectu
re:
–D
efin
es c
on
str
ain
ts o
n im
ple
me
nta
tio
n
–D
icta
tes p
roje
ct str
uctu
re
•D
ete
rmin
es to
p-le
ve
l W
BS
ele
me
nts
•F
acili
tate
s a
ccu
rate
estim
ate
s
•A
ssis
ts w
ith
pe
rso
nne
l a
lloca
tio
n
–In
hib
its o
r e
na
ble
s r
eu
se
an
d p
rod
uct q
ua
lity
–F
acili
tate
s p
roo
fs-o
f-co
nce
pt a
nd
pro
toty
pin
g
–H
elp
s w
ith c
ha
ng
e m
an
ag
em
en
t.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W6
Syste
m V
iew
poin
ts
•W
hic
h o
f th
ese
do y
ou c
are
most ab
out if
you just bro
ke
your
arm
?
•W
hic
h o
ne
matters
more
to a
card
io-
logis
t?
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W7
Syste
m V
iew
poin
ts
•P
hili
ppe K
rutc
hen
art
icula
tes four
basic
vie
ws o
f a s
yste
m a
rchitectu
re in h
is
“4+
1”
vie
w m
odel.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W8
Syste
m V
iew
poin
ts
•T
he
4+
1's
lo
gic
alvie
w s
ho
ws t
he
cla
sse
s
tha
t m
ake
up
th
e s
yste
m.
•U
ML
sta
tic a
nd
dyn
am
ic m
od
els
are
use
d
for
this
pu
rpo
se
. P
art
icu
larl
y:
–R
ob
ustn
ess (
com
mu
nic
atio
n)
dia
gra
ms
–S
eq
ue
nce d
iag
ram
s
–C
lass d
iagra
ms
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W9
Syste
m V
iew
poin
ts
•T
he
4+
1's
de
ve
lop
me
nt
vie
w d
escri
be
s
the
syste
m’s
mo
du
les.
–M
od
ule
s g
en
era
lly c
on
sis
t o
f g
rou
ps o
f
rela
ted
cla
sse
s.
–P
acka
ges, su
bsyste
ms, a
nd
cla
ss lib
rarie
s
are
all
co
nsid
ere
d m
od
ule
s
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
0
Syste
m V
iew
poin
ts
•T
he
4+
1's
pro
ce
ss
vie
w d
escri
be
s t
he
inte
ractio
ns o
f syste
m’s
mo
du
les.
–T
his
vie
w d
escrib
es c
oncurr
ent
pro
cess e
xecution
and t
he inte
ractions b
etw
ee
n t
he p
rocesses.
–S
evera
l le
vers
of abstr
action m
ay b
e n
ecessary
if
the s
yste
m is h
igh
ly c
om
ple
x.
-C
an inclu
de n
onfu
nctiona
l or
qualit
y r
equ
irem
ents
lik
e
perf
orm
ance,
availa
bili
ty,
etc
.-
Activity d
iagra
ms h
elp
mode
l th
e p
rocess v
iew
.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
1
Syste
m V
iew
poin
ts
•T
he
4+
1's
ph
ysic
alvie
w d
escri
be
s h
ow
th
e
ap
plic
atio
n is in
sta
lled
an
d h
ow
it
exe
cu
tes in
a n
etw
ork
of
co
mp
ute
rs.
-T
his
vie
w takes into
accou
nt
nonfu
nction
al
requ
irem
en
ts lik
e
perf
orm
ance,
ava
ilab
ility
, re
liab
ility
,
and s
ca
lab
ility
.-
Dep
loym
ent
dia
gra
ms
he
lp m
ode
l th
e p
hysic
al
vie
w.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
2
Syste
m V
iew
poin
ts
•T
he
4+
1's
"p
lus-o
ne
" co
nsis
ts o
f u
se c
ase
s
an
d s
ce
na
rio
s t
ha
t fu
rth
er
de
scri
be
or
co
nso
lida
te t
he
oth
er
vie
ws.
-T
hese e
xp
lain
the
functiona
lity a
nd
str
uctu
res d
escri
be
d b
y
the o
ther
vie
ws.
-T
he u
se c
ase v
iew
consis
ts o
f use c
ase
dia
gra
ms a
nd
specific
atio
ns d
eta
ilin
g the
actions a
nd c
ond
itio
ns
insid
e e
ach
use c
ase.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
3
Syste
m V
iew
poin
ts
•R
oza
nskia
nd
Wo
od
s a
dd
an
In
form
atio
n
vie
w a
nd
a C
on
cu
rre
ncy v
iew
to
th
is s
et.
–T
he I
nfo
rmation v
iew
concern
s info
rmation
conte
nt,
ow
ners
hip
, tim
elin
ess,
data
qualit
y, and
ava
ilab
ility
.
•T
oo
ls:
Da
ta f
low
dia
gra
ms,
UM
L d
iag
ram
s
–C
oncurr
en
cy c
oncern
s the m
app
ing o
f fu
nctiona
l ele
ments
to t
asks, in
terp
rocess
com
munic
ation,
reentr
ancy,
and s
ynch
roniz
atio
n.
•T
oo
ls:
UM
L c
om
po
ne
nt
an
d s
tate
dia
gra
ms.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
4
Arc
hitectu
ral B
usin
ess C
ycle
•W
he
the
r in
ten
de
d o
r n
ot,
eve
ry s
yste
m h
as
an
arc
hite
ctu
re.
•T
ha
t a
rch
ite
ctu
re is a
fu
nction
of
the
:
–S
kill
of th
e a
rchitect
–C
urr
ent
techno
logy e
nvironm
ent
–S
kill
s o
f develo
pers
and s
upp
ort
sta
ff, and
–S
trate
gic
dir
ection o
f th
e s
ponsori
ng o
rgan
ization.
•T
hu
s t
he
ap
pro
ach
es t
o s
yste
m a
rch
ite
ctu
re
are
org
an
iza
tio
n s
pe
cific
an
d w
ill c
ha
ng
e o
ve
r
tim
e.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
5
Arc
hitectu
ral B
usin
ess C
ycle
Po
licie
s,
tech
no
log
y,
skill
s, str
ate
gic
vis
ion
.
Arc
hite
ctu
reIn
fluences
Infl
uences
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
6
Deplo
ym
ent A
ppro
aches
•M
on
olit
hic
lo
ca
l m
od
el: S
ing
le p
rog
ram
(o
r
co
llectio
n o
f re
late
d p
rog
ram
s)
run
nin
g w
ith
in
the
co
nfin
es o
f a
sin
gle
syste
m.
•M
od
ule
s m
ay r
esid
e in
diffe
ren
t d
ire
cto
rie
s,
an
d m
ay in
vo
lve
a s
et
of co
ncu
rre
nt
tasks.
•C
an
no
t b
e u
se
d w
he
n d
ata
re
sid
es e
lse
wh
ere
(i.e
., o
n a
ho
st
da
tab
ase
).
Where
are
the c
om
ponents
?
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
7
Arc
hitectu
ral P
rocess
•H
ow
is a
rchitectu
re d
ete
rmin
ed?
–S
ho
uld
be d
on
e b
y a
sin
gle
pe
rso
n o
r a
ve
ry
sm
all
tea
m.
–S
ho
uld
have
go
od
se
t o
f fu
nctio
na
l a
nd
n
on
fun
ction
al re
qu
ire
me
nts
–to
in
clu
de
qu
alit
y
attrib
ute
s.
–M
etr
ics fo
r th
rou
gh
pu
t, a
va
ilab
ility
, re
sp
on
se
tim
e, e
tc.
sh
ou
ld b
e d
ete
rmin
ed
.
–A
rch
itectu
re s
ho
uld
le
nd
its
elf t
o in
cre
men
tal
an
d ite
rative
de
ve
lop
me
nt a
nd
de
plo
ym
en
t.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
8
Arc
hitectu
ral D
ecis
ions
•W
hat are
the r
ule
s o
f th
um
b?
–S
yste
m s
ho
uld
co
nsis
t o
f m
od
ule
s th
at h
ave
h
igh
fu
nctio
na
l co
hesio
n a
nd
lo
w c
ou
plin
g.
–In
terf
ace
s b
etw
ee
n m
od
ule
s s
ho
uld
be
we
ll d
efin
ed
to
fa
cili
tate
te
am
-ba
sed
so
ftw
are
d
eve
lop
me
nt.
–S
ho
uld
utiliz
e c
om
me
rcia
l p
rodu
cts
with
ca
re.
•It
is d
an
ge
rou
s t
o r
ely
on
a p
art
icu
lar
ve
rsio
n o
f a
co
mm
erc
ial p
rod
uct.
•If
yo
u m
ust
utiliz
e a
co
mm
erc
ial p
rod
uct,
try
to
ke
ep
co
up
ling
to
a m
inim
um
.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W1
9
Arc
hitectu
ral D
ecis
ions
•M
ore
rule
s o
f th
um
b…
–M
od
ule
s th
at p
rod
uce
da
ta s
ho
uld
be
sep
ara
te
fro
m m
odu
les th
at co
nsum
e d
ata
.
–A
mo
du
le s
ho
uld
be
sm
all
en
ou
gh
to
be
u
nd
ers
tood
by a
sin
gle
pro
gra
mm
er.
–A
mo
du
le s
ho
uld
als
o b
e s
ma
ll e
no
ug
h s
o th
at if
the
pro
gra
mm
er
work
ing
on
it q
uits, yo
u c
an
sta
rt it o
ve
r w
ith
ou
t ca
usin
g a
ny s
ch
ed
ule
slip
pag
e.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
0
•M
on
olit
hic
ho
st m
od
el: S
ing
le p
rog
ram
(o
r
co
llectio
n o
f re
late
d p
rog
ram
s)
run
nin
g w
ith
in
the
co
nfin
es o
f a
sin
gle
re
mo
te s
yste
m.
–T
he “
sin
gle
syste
m”
may b
e a
clu
ste
r th
at is
log
ica
lly
a s
ing
le s
yste
m.
•A
cce
ss v
ia “
du
mb
te
rmin
al,”
bro
wse
r, o
r “t
hin
clie
nt.
”
•P
rovid
es b
est
se
curi
ty,
ma
na
ge
ab
ility
,
pe
rfo
rma
nce
, a
nd
ro
bu
stn
ess.
Where
are
the c
om
ponents
?
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
1
•D
istr
ibu
ted
co
mp
utin
g:
Pla
ce
s e
xe
cu
tab
le
co
mp
on
en
ts o
n m
ore
th
an
on
e p
latf
orm
.
(Co
mm
on
ly-a
cce
pte
d d
efin
itio
n.)
•A
t a
n e
xtr
em
e:
Ca
n c
on
sis
t of
hu
nd
red
s o
f
ide
ntica
l “i
nsta
nce
s”
run
nin
g o
n h
un
dre
ds o
f
dis
cre
te s
yste
ms.
•M
ost
co
mm
on
ly a
tw
o-
or
thre
e-t
ier
arc
hite
ctu
re.
Where
are
the c
om
ponents
?
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
2
•D
istr
ibu
ted
co
mp
utin
g c
om
es in
tw
o b
asic
form
s:
Pe
er-
to-p
ee
r (P
2P
) a
nd
clie
nt-
se
rve
r.
•P
2P
mo
de
ls a
re u
su
ally
se
lf-m
an
ag
ing
an
d
em
plo
ye
d in
th
e la
rge
st
dis
trib
ute
d c
om
pu
tin
g
co
nfig
ura
tio
ns (
e.g
., g
rid
com
pu
tin
g).
•C
lien
t-se
rve
r syste
ms r
ely
on
so
me
de
gre
e o
f
inte
llig
en
ce
in
mu
ltip
le c
lien
t syste
ms th
at
fun
ctio
n in
de
pe
nd
en
tly,
bu
t in
tera
ct
with
th
e
sa
me
ho
st.
Thes
e m
odel
s ar
e sh
ow
n o
n t
he
nex
t sl
ide
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
3
Pee
r-to
-Pee
r
Cli
ent-
Ser
ver
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
4
2-T
ier
Cli
ent-
Ser
ver
•C
ha
llen
ges a
re in
p
erf
orm
ance
tu
nin
g
an
d m
an
ag
em
en
t.
•B
y m
ovin
g e
xe
cu
tio
n
mo
du
les o
ff o
f th
e
se
rve
r, w
e im
pro
ve
p
erf
orm
ance
at th
e
se
rve
r.
•B
ut th
en
we
have
to
ma
na
ge
th
e c
on
fig
ur-
atio
na
t e
ach
clie
nt.
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
5
3-T
ier
Appro
ach
•S
om
e p
erf
orm
ance
im
pro
vem
en
ts c
an
be
re
aliz
ed
by s
ep
ara
tin
g
ap
plic
atio
n lo
gic
fro
m
da
ta s
tora
ge
.
•M
an
age
ab
ility
im
pro
ves b
y h
avin
g
da
ta
“com
pa
rtm
en
taliz
ed
.”
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
6
3-T
ier
Appro
ach
•T
he
effe
ctive
ness o
f th
e s
yste
m r
elie
s o
n th
e
facili
tie
s a
nd
ca
pa
bili
tie
s lo
ca
ted
h
ere
.
•W
ha
t a
re th
e issu
es?
Deplo
ym
ent A
ppro
aches
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
7
Mid
dle
ware
Requirem
ents
•C
om
mu
nic
atio
n a
nd
se
ssio
n m
an
ag
em
en
t
•S
ecu
rity
(!!
!)
•P
roce
ss m
an
ag
em
en
t–
Synchro
niz
ation
–R
esourc
e p
rote
ction
•P
erf
orm
an
ce
•S
ca
lab
ility
•T
ran
sa
ctio
n m
an
ag
em
en
t
•In
teg
ratio
n (
Da
ta a
nd
pro
ce
sse
s)
•R
elia
bili
ty (
failo
ve
r p
rote
ctio
n)
Will
yo
u h
ave t
ime
an
d m
on
ey t
o
pro
gra
m a
ll o
f th
is
stu
ff w
hile y
ou
’re
imp
lem
en
tin
g
bu
sin
ess lo
gic
?
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
8
Mid
dle
ware
Pro
ducts
•M
idd
lew
are
pro
du
cts
pro
vid
e in
fra
str
uctu
re
wh
ile y
ou
wo
rry a
bo
ut
bu
sin
ess lo
gic
.
•T
he
re a
re f
ou
r g
en
era
l
ca
teg
ori
es
–T
ransaction
al
–P
roced
ura
l
–O
bje
ct-
Orie
nte
d
–M
essag
e-O
rie
nte
d
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W2
9
Mid
dle
ware
Pro
ducts
•T
ran
sa
ctio
na
l m
idd
lew
are
•D
efin
es s
erv
ice
s in t
he
co
nte
xt
of tr
an
sa
ctio
ns
•T
wo
-ph
ase
co
mm
its fo
r re
liab
ility
•E
xa
mp
les
–C
ICS
by I
BM
–T
uxed
o b
y B
EA
–E
ncin
aby T
ransarc
•D
isa
dva
nta
ge
s–
Pro
pri
eta
ry
–Lots
of overh
ead if
transactio
n s
erv
ices n
ot
need
ed.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
0
Mid
dle
ware
Pro
ducts
•P
roce
du
ral m
idd
lew
are
is b
ase
d o
n r
em
ote
pro
ce
du
re c
alls
(R
PC
s).
•A
lo
t lik
e c
alli
ng
a p
roce
du
re w
ith
in a
pro
gra
m,
bu
t p
ara
me
ters
are
ma
rsh
ale
da
nd
pa
sse
d t
o a
pro
ce
ss r
un
nin
g o
n a
n
ap
plic
atio
n s
erv
er
tha
t u
nm
ars
ha
lsth
em
an
d
invo
ke
s th
e a
pp
rop
ria
te m
od
ule
.
•S
yn
ch
ron
ou
s e
xcha
ng
e b
etw
ee
n c
lien
t a
nd
se
rve
r.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
1
Mid
dle
ware
Pro
ducts
•E
xa
mp
les
–D
istr
ibute
d C
om
putin
g E
nvironm
ent
(DC
E)
sponsore
d b
y t
he X
/Open c
onsort
ium
–W
ind
ow
s R
PC
•D
isa
dva
nta
ge
s
–D
oe
s n
ot
sca
le w
ell
–L
acks r
ob
ustn
ess
–H
ard
to
use
–H
ard
to
in
teg
rate
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
2
Mid
dle
ware
Pro
ducts
•O
bje
ct-
ori
en
ted
mid
dle
wa
re e
xte
nd
s e
xe
cu
tio
n
en
vir
on
me
nt
usin
g d
istr
ibu
ted
ob
jects
.
•In
terf
ace
co
nsis
ts o
f “s
ke
leto
ns”
on
th
e s
erv
er
an
d “
stu
bs”
on
th
e c
lien
t.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
3
Mid
dle
ware
Pro
ducts
•E
xam
ple
s
–O
MG
’sC
om
mo
n O
bje
ct
Re
qu
est
Bro
ke
r A
rch
ite
ctu
re
(CO
RB
A)
–M
icro
so
ft’s
Co
mp
on
en
t O
bje
ct
(CO
M)
an
d D
istr
ibu
ted
C
OM
(D
CO
M)
–Ja
va
Re
mo
te M
eth
od
In
vo
ca
tio
n (
RM
I) a
nd
En
terp
rise
Ja
va
Be
an
s (
EJB
s)
•S
tre
ng
ths
–S
up
po
rts t
ran
sa
ctio
ns a
nd
exce
ptio
ns
–M
ultip
le la
ng
ua
ge
su
pp
ort
(h
ete
rog
en
eity)
•W
eakn
ess
–S
ca
lab
ility
, h
ard
to
de
plo
y.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
4
Mid
dle
ware
Pro
ducts
•M
essag
e-O
rie
nte
d M
idd
lew
are
(M
OM
)
•C
lien
t a
nd s
erv
er
com
mu
nic
ate
via
asynch
ron
ou
s
messag
es.
•M
essag
es a
re q
ue
ue
d a
t se
rve
r a
nd
an
y
inte
rme
dia
te s
yste
ms.
•O
fte
n a
sto
re-a
nd
-forw
ard
arc
hite
ctu
re (
for
relia
bili
ty)
–M
essa
ge
he
ld a
t clie
nt
or
inte
rme
dia
te n
od
e u
ntil it is
ackn
ow
led
ge
d.
•D
eliv
ery
ca
n b
e “
at le
ast o
nce
”o
r “a
t m
ost o
nce
.”
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
5
Mid
dle
ware
Pro
ducts
•M
OM
dis
ad
va
nta
ge
s
–D
oes n
ot
supp
ort
ato
mic
deliv
ery
to a
ll or
none
–C
an h
ave s
cala
bili
ty p
rob
lem
s
–H
ete
rog
en
eity: O
ften r
equ
ires inte
rmedia
te
transla
tio
n s
teps.
–Q
ueue b
uff
ers
can b
ecom
e o
verw
helm
ed,
causin
g lost m
essages.
–P
ropri
eta
ry im
ple
me
nta
tions c
ause
inte
rop
era
bili
ty p
rob
lem
s.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
6
Web S
erv
ices
•A
so
lutio
n t
o m
an
y m
idd
lew
are
pro
ble
ms.
•A
We
b s
erv
ice
is a
de
plo
ye
d m
od
ule
th
at:
–Is
availa
ble
usin
g s
tan
dard
inte
rnet
pro
tocols
–U
ses s
elf-d
escrib
ing X
ML (
exte
nsib
le m
ark
up
lang
ua
ge)
form
at fo
r m
essag
es
–E
xposes a
pub
lic,
dis
covera
ble
in
terf
ace.
–Is
lan
gua
ge a
nd p
latform
inde
pe
nde
nt.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
7
Web S
erv
ices
•A
We
b s
erv
ice
de
scrib
es its
in
terf
ace
usin
g a
W
eb
Se
rvic
e D
efin
itio
n L
an
gua
ge
(W
SD
L)
pu
blic
atio
n th
at g
ive
s th
e s
up
po
rte
d
pro
toco
ls, a
nd
pa
ram
ete
rs e
xp
ecte
d b
y th
e
se
rvic
e.
•T
he
WS
DL
is p
ub
lish
ed
to
a U
DD
I (U
niv
ers
al
Descrip
tio
n, D
isco
very
, a
nd
In
teg
ratio
n)
no
de
or
bro
ke
r th
at is
se
arc
ha
ble
ove
r th
e in
tern
et.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
8
Web S
erv
ices
•A
We
b s
erv
ice
s a
re p
rovid
ed
usin
g X
ML
fo
rma
tte
d m
essag
es.
•T
hre
e type
s:
–H
TT
P P
ost/G
et
–X
ML-R
PC
–S
OA
P -
very
much lik
e X
ML-R
PC
•M
ajo
r a
dva
nta
ge
–In
tero
pera
bili
ty
•M
ajo
r d
isad
va
nta
ge
–P
erf
orm
ance
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W3
9
Web S
erv
ices
•W
eb
se
rvic
es a
re a
key e
na
ble
r o
f se
rvic
e-
orie
nte
d-a
rch
ite
ctu
res.
–S
OA
is a
type o
f bla
ck-b
ox r
euse w
here
com
pon
ent
serv
ices a
re loose
ly c
oup
led v
ia X
ML
or
BP
EL (
exte
nsio
n o
f X
ML).
–N
ote
: S
OA
can b
e im
ple
me
nte
d u
sin
g a
ny
mid
dle
ware
pro
tocol (e
.g., C
OR
BA
, D
CO
M),
but
most ro
bust solu
tion is v
ia W
eb s
erv
ices.
Learn
all y
ou
can
ab
ou
t W
eb
serv
ices!
Go
od
beg
inn
er
bo
ok:
Web
Servic
es E
ssen
tials
(O’R
eilly
0-5
96-0
0224-6
)
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
0
Ente
rprise S
erv
ice B
us
•L
arg
e o
rga
niz
atio
ns e
ncom
pass m
any la
rge
, q
ua
si-in
dep
en
de
nt syste
ms.
•T
he
ER
P s
yste
m m
ay n
ee
d to
co
mm
un
ica
te w
ith
a
cu
sto
m-w
ritte
n in
ve
nto
ry s
yste
m, w
hic
h m
ay
ne
ed
to
in
terf
ace
with
a P
OS
syste
m a
s w
ell
as
an
e-c
om
me
rce
clu
ste
r.
•A
nd
th
e o
rga
niz
atio
n m
ay n
ee
d to
in
terf
ace
with
“bu
sin
ess p
art
ne
rs”
such
as s
elle
rs o
r su
pp
liers
.
Busin
ess P
roble
m:
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
1
Ente
rprise S
erv
ice B
us
•“H
ub
an
d s
po
ke
”in
terf
ace
s a
re h
igh
-ma
inte
n-
an
ce
, h
ard
to
ma
na
ge
, a
nd
do
n’t s
ca
le w
ell.
Busin
ess P
roble
m:
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
2
Ente
rprise S
erv
ice B
us
•R
ep
lace
“h
ub
an
d s
po
ke
”
inte
rfa
ce
s w
ith
a s
ing
le b
us
arc
hite
ctu
re.
Busin
ess S
olu
tion:
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
3
Ente
rprise S
erv
ice B
us
•M
ost
ES
B im
ple
me
nta
tio
ns p
rovid
e:
–C
om
mon inte
rfaces (
XM
L)
–C
om
mon p
roto
cols
(S
OA
P)
–C
entr
aliz
ed
managem
ent
and a
dm
inis
tration
–U
niform
security
.
–S
tandard
s s
upp
ort
(W
S-*
)
•U
su
ally
em
plo
ys a
MO
M c
ore
•H
igh
ly s
ca
lab
le a
nd
ro
bu
st
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
4
Conclu
sio
n
•T
ho
ug
ht
ne
ed
s t
o b
e g
ive
n t
o w
he
re
co
mp
on
en
ts a
re d
ep
loye
d.
•If
no
t o
n c
en
tra
l se
rve
r, h
ow
will
th
e
co
mp
on
en
ts c
on
ne
ct
with
clie
nt
no
de
s?
•In
du
str
y tre
nd
is t
ow
ard
We
b s
erv
ices (
eve
n
with
pe
rfo
rma
nce
pro
ble
ms).
•L
arg
e c
om
pa
nie
s (
or
go
ve
rnm
en
t) c
an
justify
ES
B in
ve
stm
en
t b
eca
use
of
hig
h
inte
gra
tio
n n
ee
ds.
(c)
200
7 J
ulia
M.
Lobu
rC
OM
P4
13
W4
5
Refe
rences
•B
ass, Len, P
aul C
lem
ents
, and R
ick K
azm
an
Softw
are
A
rchitectu
re In P
ractice 2
/e A
ddis
on-W
esle
y 2
007.
•K
ruchte
n, P
hili
ppe. "T
he 4
+1 V
iew
Model of A
rchitectu
re,"
IE
EE
Softw
are
, vol.
12,
no.6,
pp. 42-5
0,
Nov.,
1995
•C
happell
David
A. E
nte
rprise S
erv
ice B
us
O'R
eill
y M
edia
, 2004
•C
era
miE
than. W
eb S
erv
ices E
ssentials
O'R
eill
y M
edia
. 2002
•R
ozanski, N
ick a
nd E
oin
Woods. S
oftw
are
Syste
ms
Arc
hitectu
re: W
ork
ing w
ith S
takehold
ers
Usin
g V
iew
poin
ts a
nd
Pers
pectives.A
ddis
on-W
esle
y 2
005.
