<s>
mod_jk	O
is	O
an	O
Apache	B-Application
module	I-Application
used	O
to	O
connect	O
the	O
Tomcat	B-Language
servlet	B-Language
container	I-Language
with	O
web	B-Application
servers	I-Application
such	O
as	O
Apache	B-Application
,	O
iPlanet	B-Application
,	O
Sun	O
ONE	O
(	O
formerly	O
Netscape	O
)	O
and	O
even	O
IIS	B-Application
using	O
the	O
Apache	B-Application
JServ	I-Application
Protocol	I-Application
.	O
</s>
<s>
A	O
web	B-Application
server	I-Application
waits	O
for	O
client	O
HTTP	O
requests	O
.	O
</s>
<s>
Adding	O
a	O
servlet	B-Language
container	I-Language
alters	O
this	O
behavior	O
.	O
</s>
<s>
Now	O
the	O
web	B-Application
server	I-Application
needs	O
also	O
to	O
:	O
</s>
<s>
Load	O
the	O
servlet	B-Language
container	I-Language
adapter	O
library	O
and	O
initialize	O
it	O
(	O
prior	O
to	O
serving	O
requests	O
)	O
.	O
</s>
<s>
When	O
a	O
request	O
arrives	O
,	O
it	O
needs	O
to	O
check	O
and	O
see	O
if	O
a	O
certain	O
request	O
belongs	O
to	O
a	O
servlet	B-Application
,	O
if	O
so	O
it	O
needs	O
to	O
let	O
the	O
adapter	O
take	O
the	O
request	O
and	O
handle	O
it	O
.	O
</s>
<s>
Things	O
are	O
more	O
complex	O
when	O
the	O
user	O
wants	O
to	O
set	O
a	O
configuration	O
that	O
uses	O
virtual	O
hosts	O
,	O
or	O
when	O
they	O
want	O
multiple	O
developers	O
to	O
work	O
on	O
the	O
same	O
web	B-Application
server	I-Application
but	O
on	O
different	O
servlet	B-Language
container	I-Language
JVMs	O
.	O
</s>
