<s>
The	O
Apache	B-Application
JServ	I-Application
Protocol	I-Application
(	O
AJP	O
)	O
is	O
a	O
binary	O
protocol	O
that	O
can	O
proxy	B-Application
inbound	O
requests	O
from	O
a	O
web	B-Application
server	I-Application
through	O
to	O
an	O
application	B-Application
server	I-Application
that	O
sits	O
behind	O
the	O
web	B-Application
server	I-Application
.	O
</s>
<s>
AJP	O
is	O
a	O
highly	O
trusted	O
protocol	O
and	O
should	O
never	O
be	O
exposed	O
to	O
untrusted	O
clients	O
,	O
which	O
could	O
use	O
it	O
to	O
gain	O
access	O
to	O
sensitive	O
information	O
or	O
execute	O
code	O
on	O
the	O
application	B-Application
server	I-Application
.	O
</s>
<s>
It	O
also	O
supports	O
some	O
monitoring	O
in	O
that	O
the	O
web	B-Application
server	I-Application
can	O
ping	B-Protocol
the	O
application	B-Application
server	I-Application
.	O
</s>
<s>
Web	O
implementors	O
typically	O
use	O
AJP	O
in	O
a	O
load-balanced	B-Application
deployment	O
where	O
one	O
or	O
more	O
front-end	O
web	B-Application
servers	I-Application
feed	O
requests	O
into	O
one	O
or	O
more	O
application	B-Application
servers	I-Application
.	O
</s>
<s>
Sessions	O
are	O
redirected	O
to	O
the	O
correct	O
application	B-Application
server	I-Application
using	O
a	O
routing	O
mechanism	O
wherein	O
each	O
application	B-Application
server	I-Application
instance	O
gets	O
a	O
name	O
(	O
called	O
a	O
route	O
)	O
.	O
</s>
<s>
In	O
this	O
scenario	O
the	O
web	B-Application
server	I-Application
functions	O
as	O
a	O
reverse	B-General_Concept
proxy	I-General_Concept
for	O
the	O
application	B-Application
server	I-Application
.	O
</s>
<s>
Lastly	O
,	O
AJP	O
supports	O
request	O
attributes	O
which	O
,	O
when	O
populated	O
with	O
environment-specific	O
settings	O
in	O
the	O
reverse	B-General_Concept
proxy	I-General_Concept
,	O
provides	O
for	O
secure	O
communication	O
between	O
the	O
reverse	B-General_Concept
proxy	I-General_Concept
and	O
application	B-Application
server	I-Application
.	O
</s>
<s>
AJP	O
runs	O
in	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
1.x	O
using	O
the	O
plugin	B-Application
and	O
in	O
Apache	B-Application
2.x	O
using	O
,	O
and	O
proxy	B-Application
balancer	O
modules	O
together	O
.	O
</s>
<s>
Other	O
web	B-Application
server	I-Application
implementations	O
exist	O
for	O
:	O
lighttpd	B-Protocol
1.4.59	O
,	O
nginx	B-Operating_System
,	O
Grizzly	B-Language
2.1	O
,	O
and	O
the	O
Internet	B-Application
Information	I-Application
Services	I-Application
.	O
</s>
<s>
Web	B-Language
container	I-Language
application	B-Application
servers	I-Application
supporting	O
AJP	O
include	O
:	O
Apache	B-Language
Tomcat	I-Language
,	O
WildFly	B-Language
(	O
formerly	O
JBoss	B-Language
AS	I-Language
)	O
,	O
and	O
GlassFish	B-Language
.	O
</s>
<s>
Alexei	O
Kosut	O
originally	O
developed	O
the	O
Apache	B-Application
JServ	I-Application
Protocol	I-Application
in	O
July	O
1997	O
but	O
the	O
version	O
1.0	O
specification	O
was	O
published	O
later	O
on	O
July	O
29	O
,	O
1998	O
.	O
</s>
<s>
He	O
also	O
wrote	O
the	O
first	O
implementations	O
of	O
it	O
in	O
the	O
same	O
month	O
,	O
with	O
the	O
releases	O
of	O
the	O
Apache	B-Application
JServ	I-Application
servlet	B-Application
engine	O
0.9	O
and	O
the	O
Apache	B-Application
mod_jserv	O
0.9a	O
(	O
released	O
on	O
July	O
30	O
,	O
1997	O
)	O
.	O
</s>
<s>
In	O
1999	O
,	O
Sun	O
Microsystems	O
donated	O
their	O
JavaServer	O
Web	O
Development	O
Kit	O
(	O
JSWDK	O
;	O
codenamed	O
Tomcat	B-Language
)	O
reference	O
implementation	O
to	O
Apache	B-Application
Software	O
Foundation	O
.	O
</s>
<s>
This	O
became	O
Apache	B-Language
Tomcat	I-Language
version	O
3.0	O
,	O
the	O
successor	O
to	O
JSWDK	O
2.1	O
,	O
and	O
derailed	O
further	O
development	O
of	O
Apache	B-Application
JServ	I-Application
servlet	B-Application
engine	O
and	O
AJP	O
towards	O
support	O
of	O
Java	B-Application
servlet	I-Application
API	I-Application
version	O
2.1	O
.	O
</s>
