module 8: concepts of a network load balancing cluster
DESCRIPTION
Module 8: Concepts of a Network Load Balancing Cluster. Overview. Network Load Balancing Concepts Application and Service Environment Network Load Balancing Functionality Network Load Balancing Architecture. Network Load Balancing Concepts. Comparing Network Load Balancing Solutions - PowerPoint PPT PresentationTRANSCRIPT
Module 8: Concepts of a Network Load
Balancing Cluster
Overview
Network Load Balancing Concepts
Application and Service Environment
Network Load Balancing Functionality
Network Load Balancing Architecture
Network Load Balancing Concepts
Comparing Network Load Balancing Solutions
Network Load Balancing
Comparing Network Load Balancing Solutions
Round robin DNSRound robin DNSRound robin DNSRound robin DNS
Easy to InstallEasy to Install YesYes
Hardware Requirements
Hardware Requirements ________
Single Point of Failure
Single Point of Failure ________
Easily Scalable
Easily Scalable YesYes
High Performance
High Performance YesYes
HardwareHardwareHardwareHardware
________
YesYes
YesYes
________
YesYes
DispatchDispatchDispatchDispatch
________
________
YesYes
LimitedLimited
LimitedLimited
NLBNLBNLBNLB
YesYes
________
________
YesYes
YesYes
Fault Tolerance
Fault Tolerance NoNo LimitedLimited LimitedLimited YesYes
Network Load Balancing
Cluster with up to32 hostsCluster with up to32 hosts
Round Robin DNSStatic groupRound Robin DNSStatic group
MyRRDNSWeb IN A 10.10.10.12MyRRDNSWeb IN A 10.10.10.11MyRRDNSWeb IN A 10.10.10.10MyNLBWeb IN A 10.10.20.10
10.10.10.1210.10.20.1110.10.20.10
10.10.20.10
11
22
33
55
DNS ServerDNS Server
66
44
IP: 10.10.10.12IP: 10.10.10.12
IP: 10.10.10.11IP: 10.10.10.11
IP: 10.10.10.10IP: 10.10.10.10
IP: 10.10.20.10IP: 10.10.20.10
Application and Service Environment
IIS Web site imageIIS Web site image
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10Web server TCP(80)Web server TCP(80)HTTPSHTTPS TCP(443) TCP(443)
Port Rules define which ports the cluster will
service
Affinity sets all client connections to a single
host
IIS Web site imageIIS Web site image
Client TCP Session (Get)Client TCP Session (Get)
Next client TCP Session (HTTPS)Next client TCP Session (HTTPS)
Applications and Services
Compatible Network Load Balancing Applications and Services
Use TCP connections or UDP data streams Support client updateable data stores Support maintenance of client session state
Incompatible Network Load Balancing Applications and Services
Bind to or reference computer names Hold files exclusively and continuously open
Network Load Balancing Functionality
Balancing Client Connections
Supporting Multiple Client Connections
Cluster Convergence
Network Load Balancing for High Availability
Network Load Balancing for Scalability
Scaling Network Load Balancing Clusters
Balancing Client Connections
Even BalanceEven Balance
Load to virtual IP distributed evenly
across hosts
1/31/3
1/31/3
1/31/3
Priority BasedPriority Based
11
22
33
All load to virtual IP distributed to
highest priority host
Manual BalanceManual Balance
30%30%
60%60%
10%10%
Load to virtual IP distributed based on manual configuration
Supporting Multiple Client Connections
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
Initial Client TCP sessionInitial Client TCP session
Initial client request distributed according to Network Load Balancing configuration
Subsequent client requests distributed according to Network Load Balancing configuration
Even balancewithout affinityEven balancewithout affinity
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
Initial Client TCP sessionInitial Client TCP session
Even balancewith affinityEven balancewith affinity
Initial client request distributed according to Network Load Balancing configuration
Subsequent client requests accepted by the same server for that client IP address
Cluster Convergence
Load balance 1/3 each Server B Fails Convergence Load Balance ½ each
Load Balance ½ each Server B Joins Convergence Load Balance 1/3 each
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
AABBCC
Even balanceEven balance
AABBCC
Even balanceEven balance
Network Load Balancing for High Availability
Load All on Host 1 Server 1 Fails Convergence Load All on Server 2
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
PriorityPriority
112233
N-1 Failover
Load balance 1/3 each Server B Fails Convergence Load Balance ½ each
Virtual IP: 10.10.10.10Virtual IP: 10.10.10.10
AABBCC
Even balanceEven balance
Network Load Balancing for Scalability
Virtual IP: 10.10.10.10
CPUsCPUs MemoryMemory
DiskDiskNICNIC
Network Load Balancing Cluster
Network Load Balancing Cluster
Scale upAdd more resources to a server
Scale upAdd more resources to a server
Scale outAdd more servers to the cluster
Scale outAdd more servers to the cluster
Scaling Network Load Balancing Clusters
Cluster 2 with upto 32 hostsCluster 2 with upto 32 hosts
10.10.10.1010.10.20.10
10.10.20.1010.10.10.10
11
22
33
66
DNS ServerDNS Server
55
44
Virtual IP: 10.10.20.10Virtual IP: 10.10.20.10
Cluster 1 with up to 32 hostsCluster 1 with up to 32 hosts
Virtual IP: 10.10.20.10Virtual IP: 10.10.20.10
•Query DNS for MybigWeb•DNS resolves to list of IPs•Client selects first in list•Creates session with server
DNS rotates list for each query which statically load balances incoming requests
•Query DNS for MybigWeb•DNS resolves to list of IP’s•Client selects first in list•Creates session with server
MybigWeb IN A 10.10.10.10MybigWeb IN A 10.10.20.10
Network Load Balancing Architecture
Network Load Balancing Driver Architecture
Network Load Balancing Topology
Selecting an IP Transmission Mode
Network Load Balancing Addressing
Port Rules
Affinity
Network Load Balancing Driver Architecture
Cluster Host
Server Application Wlbs.exe
Windows 2000 Kernel
TCP/IP
Network Load Balancing Driver
Network AdapterDriver
Network AdapterDriver
ClusterNetwork Adapter
ClusterNetwork Adapter
LANLAN
Network Load Balancing Topology
Cluster with 3 hosts
Cluster with 3 hosts
Hub or switchHub or switch
Hub or switchHub or switch
RouterRouter
Virtual IP: 10.10.10.10Single SubnetMulticast or UnicastCommon MAC address
Driver configuration
Inbound trafficInbound traffic
Outbound traffic andInbound to dedicated IPOutbound traffic and
Inbound to dedicated IP
Selecting an IP Transmission Mode
AdaptersAdaptersAdaptersAdapters
SingleSingle
SingleSingle
MultipleMultiple
MultipleMultiple
ModeModeModeMode
UnicastUnicast
MulticastMulticast
UnicastUnicast
MulticastMulticast
MACMACMACMAC
SingleSingle
MultipleMultiple
MultipleMultiple
MultipleMultiple
AdvantageAdvantageAdvantageAdvantage
SimpleSimple
Medium Performance
Medium Performance
Best BalanceBest Balance
Best BalanceBest Balance
DisadvantageDisadvantageDisadvantageDisadvantage
Low peer performanceLow peer
performance
ComplexComplex
NoneNone
Complex Network Configuration
Complex Network Configuration
Network Load Balancing Addressing
Cluster with 3 hosts
Cluster with 3 hosts
Virtual IP: 10.10.10.10Single SubnetMulticast or UnicastCommon MAC address
Example • Clients access DNS to resolve IP address• Clients ARP to resolve IP to MAC• All cluster hosts reply to ARP• Client Syn to start TCP connection• Server Asyn for selected cluster host• Client ASyn
Note:• All client traffic arrives at all hosts for virtual IP• Algorithm selected host replies• Traffic to dedicated IP can be the same MAC address
Hub or switchHub or switch
Port Rules
Port Rules
Filtering Modes
Load Weighting
Priority
Affinity
AffinityAffinityAffinityAffinity Load balancingLoad balancinggranularitygranularity
Load balancingLoad balancinggranularitygranularity
AlgorithmAlgorithmhashes onhashes on
AlgorithmAlgorithmhashes onhashes on Used forUsed forUsed forUsed for
NoneNone Individual TCP connections
Individual TCP connections
SingleSingleAll connections
originating from the same source
All connections originating from the
same source
Class CClass C
All connections originating from the
same Class C address space
All connections originating from the
same Class C address space
Source IP address and port
Source IP address and port
Source IP addressSource IP address
Source IP address with Class C mask
applied to it
Source IP address with Class C mask
applied to it
Most applicationsMost applications
Session support, SSL and multi-connection protocols (ex: FTP,
PPTP, etc.)
Session support, SSL and multi-connection protocols (ex: FTP,
PPTP, etc.)
Property handling sessions for users
residing behind scaling proxy arrays
Property handling sessions for users
residing behind scaling proxy arrays
Lab A: Planning an Installation
Review
Network Load Balancing Concepts
Application and Service Environment
Network Load Balancing Functionality
Network Load Balancing Architecture
TCP/IP
NLB Driver
Network AdapterDriver
ClusterNetwork Adapter
Holds Port rules for all inbound traffic
Network Load Balancing Driver Architecture
Assigns Common Virtual IP and MAC address
Virtual IP: 10.10.10.10MAC: 02-BF-10-10-10-10
All Virtual IP traffic will be filtered by NLB rules
Adapter can be Ethernet, Gigabit Ethernet or FDDI