ACE LOAD BALANCER: UNDERSTANDING TOPOLOGY, CLI MODE


NOTE

ALL CONFIGURATIONS ARE EXTRACTED FROM REAL WORLD ENVIRONMENT

 

Modes Of Login

GUI and SSH

What is Server Farm ?

DESCRIPTION

Server Farm is grouping of Physical servers on which a particular application is load balanced.

This is done for Redundancy purpose, if one Physical server goes down, other Physical servers must be there to access the application which is Load Balanced.

 

CONFIG

To check ServerFarm
ACE-PlanB/SNAT# sh serverfarm

Codes: L – local, R – remote

serverfarm type rservers predictor current conns
+——————–+———+——–+——————+—————
SF_Click1
HOST 5 LEASTCONNS 4
SF_ClickApp
HOST 2 LEASTCONNS 0

 

COMMENTS

It means as per first serverfarm, SF_Click1, application is load balanced on 5 hosts or Physical servers

Algorithm used to Load Balance Traffic on Physical Servers in a server farm, is LEAST CONNECTIONS.

LEAST CONNECTION means, request to access application running on servers, will go to the Physical server, on which Least Connections are established.

What is probing ?

DESCRIPTION

For Server Farms, probing or simply inspection is done regularly to confirm normal functioning.

For different Server Farms, Different probing profiles are configured as per scenario

In different Probing Profiles, there are different parameters to do inspection for Server Farms

 

CONFIG
ACE-DMZ1/DMZ_VC# sh probe

probe       : PR_HTTPS1
type        : HTTPS

state       : ACTIVE

port      : 443     address     : 0.0.0.0         addr type  : –
interval  : 15      pass intvl  : 60              pass count : 3
fail count: 3       recv timeout: 10
—————— probe results ——————
associations ip-address      port  porttype probes   failed   passed   health

———— —————+—–+——–+——–+——–+——–+——

serverfarm  : SF_WebEnroll
real      : TORAPP38[443]
10.159.24.130   443   REAL     211847   380      211467   SUCCESS

real      : TORAPP50[443]
10.159.24.131   443   REAL     211862   360      211502   SUCCESS

 

COMMENTS

Probing Profile Name: PR_HTTPS1

Probing Profile is configured to do probing for serverfarm, SF_WebEnroll

serverfarm, SF_WebEnroll  consists of Physical servers, TORAPP38  &  TORAPP50

 

What is context in load balancer ?

DESCRIPTION

In a single Physical device or Load Balancer, we can create different profiles. These profiles are called context here.

In these Profiles or Contexts, we have created the Server Farms

By default, when we Login to the Load Balancer, we land up in Admin Context

To switch to other profiles, use command:
“”changeto “”

 

CONFIG

ACE-PlanB/Admin# changeto ?
Admin
DR
PlanB
Redirect
SNAT
COMMENTS

Admin, DR, PlanB, Redirect, SNAT  are all Profiles or Contexts configured here

 

How to do Health Check-up of servers ?

DESCRIPTION

By this, we can confirm if Physical Servers in a Server Farm are working fine or not

 

CONFIG
ACE-PlanB/Admin# changeto ?
Admin
DR
PlanB
Redirect
SNAT
ACE-PlanB/Admin# changeto SNAT
ACE-PlanB/SNAT# sh probe

probe : PR_ClickApp
type : HTTP

state : ACTIVE

port : 80 address : 0.0.0.0 addr type : –
interval : 10 pass intvl : 30 pass count : 1
fail count: 3 recv timeout: 10
—————— probe results ——————
associations ip-address port porttype probes failed passed health

———— —————+—–+——–+——–+——–+——–+——

serverfarm : SF_ClickApp
real : S_TORAPP217[0]
10.144.3.78 80 DEFAULT 1028531 780410 248121 FAILED

real : S_TORAPP218[0]
10.144.3.80 80 DEFAULT 1166575 710628 455947 SUCCESS

 

COMMENTS

By probing, we came to know that Physical Server, S_TORAPP217 is not in service

By probing, we came to know that Physical Server, S_TORAPP218 is working fine

 

How to check configured VLAN’s ?

ACE-DMZ1/Admin# sh vlans

Vlans configured on physical port(s)

vlan574 vlan702-703

 

EXPLAIN

CONFIG

Context Admin

IP ADDRESS      MAC-ADDRESS            Interface  Type      Encap  NextArp(s) Status

10.159.24.1     00.1c.7f.40.16.f7  vlan574   GATEWAY    13     206 sec      up
10.159.24.6     00.1b.24.5e.84.e9  vlan574   INTERFACE  LOCAL     _         up
10.159.24.7     00.1b.24.5e.8a.3e  vlan574   LEARNED    11     207 sec      up
10.159.9.170    00.1b.24.5e.84.e9  vlan702   INTERFACE  LOCAL     _         up

10.159.9.169    00.1b.24.5e.8a.3e  vlan702   LEARNED    5      1208 sec     up

 

COMMENTS

It is showing the IP’s related to its own & other connected Load Balancer

 

EXPLAIN

CONFIG

ACE-DMZ1/Admin# sh conn

total current connections : 23

conn-id   np dir proto vlan source               destination           state

———-+–+—+—–+—-+———————+———————+——+

1         1 in UDP   702 10.159.9.169:50002   10.159.9.170:50000   —

2         1 in UDP   702 10.159.9.169:50102   10.159.9.170:50100   —

980688     1 in TCP   574 10.146.197.83:63275   10.159.24.6:22       ESTAB

980689     1 out TCP   574 10.159.24.6:22       10.146.197.83:63275   ESTAB

1495840   1 in TCP   702 10.159.9.169:9080     10.159.9.170:2000     ESTAB

1495841   1 out TCP   702 10.159.9.170:2000    10.159.9.169:9080     ESTAB

 

COMMENTS

Output shows all the TCP & UDP connection established with current Load Balancer

 

How to check Serial Number of Load Balancer?

CONFIG

ACE-DMZ1/Admin# sh hardware

Product Number: ACE-4710-K9

Serial Number: QCN1214004Y

Hardware Rev:   65535.65535

VID:           V02

CLEI:           COUCAFJCAA

MFG Part Num:   800-29070-02

MFG Revision:   A0

Slot No. :     1

Type:           ACE Appliance

 

 

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s