8-49
User
Guide

for

the

Cisco

Application

Networking

Manager

5.2
OL-26572-01
Chapter
8






Configuring

Real

Servers

and

Server

Farms
Configuring
Health

Monitoring
Procedure
Step
1
Choose
Config
>

Devices

>

context

>

Load

Balancing

>

Server

Farms.
The
Server

Farms

table

appears.
Step
2
In
the
Server
Farms

t

able,

choose

a

se

rver

farm

from

the
Server
Farms

t

able,
and
cl

ick
Details.
The
show

serverfarm

name

detail

CLI

command

output

appears.

For

details

about

the

displayed

output
fields,
see

the

Cisco

ACE

Module

Server

Load-Balancing

Configuration

Guide

or


the

Cisco

ACE

4700
Series
Appliance

Server

Load-Balancing

Configuration

Guide,

Chapter

2,

Configuring

Real

Servers

and
Server
Farms.
Step
3
Click
Update
Details

to

refresh

the

output
for
the
show
serverfarm

name

detail

CLI

command.
The
new

information

appears

in

a

separate

panel

with

a

new

timestamp;

both

the

old

and

the

new

server
farm
statistics

and

status

information

appear

side-by-side

to

avoid

overwriting

the

last

updated
information.
Step
4
Click
Close
to
return
to
the

Server

Farms

table.
Related
Topics

•
Displaying
All

Server

Farms,

page
8-48

•
Configuring
Server
Farms,
page
8-30

•
Adding
Real

Servers

to

a

Server

Farm,

page
8-37

•
Configuring
the

Predictor

Method
for
Server

Farms,

page
8-39

•
Configuring
Server

Farm

HTTP

Return
Error-Code
Checking,

page
8-46

•
Configuring
Dynamic

Workload

Scaling,

page
8-26
Configuring
Health

Monitoring
You
can

instruct

the

ACE

to

check

the

health

of

servers

and

server

farms

by

configuring

health

probes
(sometimes
referred

to

as

keepalives).

After

you

create

a

probe,

you

assign

it

to

a

real

server

or

a

server
farm.
A

probe

can

be

one

of

many

types,

including

TCP,

ICMP,

Telnet,

HTTP,

and

so

on.

You

can

also
configure
scripted

probes

using

the

TCL

scripting

language

(see

the

“TCL

Scripts”

section

on
page
8-50 ).
The
ACE

sends

out

probes

periodically

to

determine

the

status

of

a

server,

verifies

the

server

response,
and
checks

for

other

network

problems

that

may

prevent

a

client

from

reaching

a

server.

Based

on

the
server
response,

the

ACE

can

place

the

server

in

or

out

of

service,

and,

based

on

the

status

of

the

servers
in
the

server

farm,

it

can

make

reliable

load-balancing

decisions.
Health
monitoring

on

the

ACE

tracks

the

state

of

a

server

by

sending

out

probes.

Also

referred

to

as
out-of-band
health

monitoring,

the

ACE

verifies

the

server

response

or

checks

for

any

network

problems
that
can

prevent

a

client

to

reach

a

server.

Based

on

the

server

response,

the

ACE

can

place

the

server

in
or
out

of


service,

and

can

make

reliable

l

oad-balancing

decisions.
The
ACE

identifies

the

health

of

a

server

in

the

following

categories:

•
Passed—The
server
returns

a

valid

response.

•
Failed—The
server

fails

to

provide

a

valid
response
to
the
ACE

or
the
ACE

is

unable

to

reach
a
server
for


a

specified

number

of

re

tries.