7-45

User

Guide

for

the

Cisco

Application

Networking

Manager

5.2

OL-26572-01

Chapter

7

Configuring

Virtual

Servers

Configuring

Virtual

Servers

Least

Bandwidth

Method

that

indicates

that

the

ACE

is

to

select

the

server

with

the

least

amount

of

network

traffic

over

a

specified

sampling

period.

a.

In

the

Assess

Time

field,

enter

the

number

of

seconds

for

which

the

ACE

is

to

collect

traffic

information.

Valid

entries

are

from

1

to

10

seconds.

b.

In

the

Least

Bandwidth

Samples

field,

enter

the

number

of

samples

over

which

you

want

to

weight

and

average

the

results

of

the

probe

query

to

calculate

the

final

load

value.

Valid

entries

are

1,

2,

4,

8,

and

16

(values

from

1

to

16

t

hat

are

also

a

power

of

2).

Least

Connections

Method

that

indicates

that

the

ACE

is

to

select

the

server

with

the

fewest

number

of

connections.

In

the

Slowstart

Duration

field,

enter

the

slow-start

value

to

be

applied

to

this

predictor

method.

Valid

entries

ar

e

fr

om

1

t

o

65535,

where

1

i

s

the

sl

owest

ramp-up

value.

The

slow-start

mechanism

is

used

to

avoid

sending

a

high

rate

of

new

connections

to

servers

that

you

have

just

put

into

service.

Least

Lo

aded

Method

that

indicates

that

the

ACE

is

to

select

the

server

with

the

lowest

load

based

on

information

from

SNMP

probes.

a.

In

the

SNMP

Probe

Name

field,

choose

the

name

of

the

SNMP

probe

to

use.

b.

In

the

Auto

Adjust

field,

configure

the

autoadjust

feature

to

assign

a

maximum

load

value

of

16000

to

that

server

to

prevent

it

from

being

flooded

with

new

incoming

connections.

The

ACE

periodically

adjusts

this

l

oad

value

based

on

feedback

from

the

server's

SNMP

probe

and

ot

her

configured

options.

Options

include:

–

Average—Instructs

the

ACE

to

apply

the

average

load

of

the

server

farm

to

a

real

server

whose

load

reaches

zero.

The

average

load

is

the

running

average

of

the

load

values

across

all

real

servers

in

the

server

farm.

This

is

the

default

setting.

–

Maxload—Instructs

the

ACE

to

apply

the

maximum

load

of

the

server

farm

to

a

real

server

whose

load

reaches

zero.

The

maxload

option

requires

the

following

ACE

software

versions:

-

ACE

appliance—A3(2.7)

or

A4(1.0)

or

later

-

ACE

module—A2(2.4),

A2(3.2),

or

A4(1.0)

or

l

ater

If

you

choose

the

maxload

option

and

the

ACE

does

not

support

the

option,

ANM

issues

a

command

parse

error

message.

–

Off—Instructs

the

ACE

to

send

all

new

connections

to

the

server

that

has

a

load

of

zero

until

the

next

load

update

arrives

from

t

he

SNMP

pr

obe

for

this

ser

ver.

There

may

be

times

when

you

want

the

ACE

to

send

all

new

connections

to

a

real

server

whose

load

is

zero.

c.

In

th

e

Weight

Connection

field,

check

th

e

ch

eck

box

to

i

nstruct

th

e

ACE

to

use

t

he

current

connection

count

in

the

final

load

calculation

for

a

real

server.

When

you

configure

this

option,

the

ACE

includes

the

current

connection

count

in

the

total

load

calculation

for

each

real

server

in

a

server

farm.

Uncheck

the

check

box

to

reset

the

behavior

of

the

ACE

to

the

default

of

excluding

the

current

connection

count

from

the

load

calculation.

Table

7-14

Predictor

Methods

and

Attributes

(continued)