Cisco Server Load Balancing

The Cisco Server Load Balancing pattern builds the BMC Discovery load balancer model based on additional details obtained via SNMP for the configured Virtual Servers, Server Farms and Real Servers from Cisco devices that support the Server Load Balancing (SLB) feature.

All configuration is obtained from SNMP tables defined in CISCO-SLB-MIB. Any configuration no longer reported is removed from the model.

Devices known to support the SLB feature:

Catalyst 6500 family switches
Cisco 7600 series routers
Cisco 7300 series routers
Cisco 7200 series routers
Cisco 7100 series routers

Load Balancer Model

Cisco Server Load Balancing uses the following conceptual model:

Virtual Server (n) - (1) Server Farm (n) - (n) Real Server

A Virtual Server is modeled as a LoadBalancerService.

A Server Farm is modeled as a LoadBalancerPool.

A Real Server is modeled as a LoadBalancerMember.

Supported virtual server states

OutOfService
InService
Standby
InOperReal
StbInOperReal
TestReal
OutOfMemory

Supported virtual service types

none
ftp
wsp
gtp
rtsp

Supported balancing methods (algorithms)

RoundRobin
LeastConns
IpHash
IpHashSrc
IpHashDest
UrlHash
Forward
LeastLoaded
HttpCookieHash
HttpHeaderHash
Layer4PayloadHash
ResponseTime
LeastBandwidth
HttpContentHash

Supported protocol types

ip
icmp
igmp
ipinip
tcp
igrp
udp
gre
esp
ah
icmp6
eigrp
ospf
nos
pim
pcp
snp

Supported Server Farm NAT types

The type of NAT employed for servers in the server farm

NoNat
ClientNat
ServerNat
ClientAndServerNat

Supported Real Server States

OutOfService
InService
Failed
ReadyToTest
Testing
MaxConnsThrottle
MaxClientsThrottle
DfpThrottle
ProbeFailed
ProbeTesting
OperWait
TestWait
InbandProbeFailed
ReturnCodeFailed
ArpFailed
Standby
Inactive
MaxLoad

Modeled Load Balancer Components

Load Balancer Instance

The pattern creates a Load Balancer Instance with the following attributes:

Attributes	Value
key	A hash of the device key and load balancer type.
type	A load balancer type.
name	A %LB_TYPE% on %device.name%.
instance_version	A version of the device OS.

The pattern models a network service relationship between the device and the Load Balancer Instance.

Load Balancer Pool

The pattern creates a Load Balancer Pool with the following attributes:

Attributes	Value
key	A hash of the instance key and pool name.
name	A pool name.
algorithm	A balancing method (algorithm) used.
nat_type	A Server Farm NAT type used.
_config_hash	Contains a hash of the pool name, algorithm, and nat_type.

The pattern models a containment relationship between the Load Balancer Instance and a Load Balancer Pool.

Load Balancer Service

The pattern creates a Load Balancer Service with the following attributes:

Attributes	Value
key	A hash of the instance key, virtual server name, ip address, and port.
name	A virtual server name.
ip_addr	A virtual server IP address.
port	A virtual server port.
type	A virtual server type.
protocol	A virtual server protocol type.
state	A virtual server state.
dns_names	A dns name of a virtual server IP address.
_config_hash	Contains a hash of the virtual server name, IP address, port, type, protocol, and state.

The pattern models a containment relationship between the Load Balancer Instance and a Load Balancer Service.

If the virtual server is configured to be a part of the server farm, the pattern models a containment relationship between the Load Balancer Service and a Load Balancer Pool.

Load Balancer Member

The pattern creates a Load Balancer Member for every real server and populates the following attributes:

Attributes	Value
key	A hash of the instance key, IP address and port of the real server.
ip_addr	A real server IP address.
port	A real server port.
name	A pair of real server IP address and port.
state	A real server state.
_config_hash	Contains a hash of the real server ip address, port, and type.

The pattern models a containment relationship between the Load Balancer Pool and a Load Balancer Member.