8-51
User
Guide

for

the

Cisco

Application

Networking

Manager

5.2
OL-26572-01
Chapter
8






Configuring

Real

Servers

and

Server

Farms
Configuring
Health

Monitoring

•
RTSP_PROBE

•
SSL_PROBE_SCRIPT
These
scripts

are

located

in

the

probe:

directory

and

are

accessible

in

both

the

Admin

and

user

contexts.
Note
t

hat

t

he

script

files

in

t

he

probe:

di

rectory

ar

e

read-only,

so

you

cannot

copy

or

mo

dify

t

hem.
However,
you

can

copy

files

from

the

probe:

directory.

For

more

information,

see

either

the

Cisco
Application
Control

Engine

Module

Administration

Guide

or

the

Cisco

4700

Series

Application

Control
Engine
Appliance

Administration

Guide.
To
load

a

script

into

memory

on

the

ACE

and

enable

it

for

use,

use

the

script

file

command.

For

detailed
information
on

uploading

and

executing

TCL

scripts

on

the

ACE,

see

either

the

Cisco

ACE

Module
Server
Load-Balancing

Configuration

Guide

or

t

he

Cisco

ACE

4700

Series

Appliance

Server
Load-Balancing
Configuration

Guide.
Configuring
Health

Monitoring

for

Real

Servers
You
can

establish

monitoring

of

real

servers

to

determine

their

viability

in

load-balancing

decisions.

To
check
the

health

and

availability

of

a

real

server,

the

ACE

periodically

sends

a

probe

to

the

real

server.
Depending
on

t

he

server

response,

the

ACE

determines

whether

or

not


t

o

include

t

he

server

i

n

its
load-balancing
decision.
Procedure
Step
1
Choose
Config
>

Devices

>

context

>

Load

Balancing

>

Health

Monitoring.
The
Health

Monitoring

t

able

ap

pears.
Step
2
In
the

Health

Monitoring

table,

click
Add
to

add

a

new

health

monitoring

probe,
or
choose

an

existing
entry
and

cl

ick

Edit

to

modify

it.
The
Health

Monitoring

window

appears.
Step
3
In
the

Name

field

of

the

Health

Monitoring
window,
enter
a

name

that
identifies
the

probe
and
that
associates
the

probe

with

the

real

server.
Valid
entries

ar

e

t

ext

strings

with

a

maximum

of

64

ch

aracters.
Step
4
In
the

Type
field,
choose

the

type
of
probe

that

you

want

to
use.
The
probe

type

determines

what

the

probe

sends

to

the

real

server.

See

Ta

b

l

e


8-11

for

the

types

of

probes
and
their

descriptions.
Ta
b

l

e


8-11
Probe
Types
Probe
Type
Description
DNS
Sends
a

request

to

a

DNS

server

giving

it

a

configured

domain.

To

determine

if

the

server

is

up,

the

ACE
must
receive

the

configured

IP

address

for

that

domain.
ECHO-TCP
Sends
a

string

to

the

server

and

compares

the

response

with

the

original

string.
If

the

response

string
matches
the

original,

the

server

is

marked

as

passed.

If

not,

the

ACE

retries

as

configured

before

the

server
is
marked

as

failed.
ECHO-UDP
Sends
a

string

to

the

server

and

compares

the

response

with

the

original

string.
If

the

response

string
matches
the

original,

the

server

is

marked

as

passed.

If

not,

the

ACE

retries

as

configured

before

the

server
is
marked

as

failed.
FINGER
Sends
a

probe

to

the

server

to

verify

t

hat

a

defined

username

is

a

use

rname

on

t

he

server.