may 21, 2013 deploying global server load balancing using persistent methods sam cohoon

May 21, 2013

Deploying Global Server Load BalancingUsing Persistent Methods

Sam Cohoon

© 2013 Citrix

Global Server Load Balancing

© 2013 Citrix

Global Server Load Balancing

© 2013 Citrix

Global Server Load Balancing

© 2013 Citrix

What is GSLB?

© 2013 Citrix

DNS

6

The Citrix NetScaler implementation of Global Server Load Balancing GSLB is Domain Name System (DNS) based.

© 2013 Citrix

DNS

7

© 2013 Citrix

GSLB Typical Setup

8

Global Server Load Balancing Components

© 2013 Citrix

Components

10

© 2013 Citrix

How it works - Summary

11

DNS and MEPComponents: GSLB domain, GSLB site, GSLB vserver, GSLB service

Global Server Load Balancing Configuration

© 2013 Citrix

GSLB Configuration

13

Where do I start?

© 2013 Citrix

GSLB Wizard

14

© 2013 Citrix

GSLB DNS DOMAIN

15

© 2013 Citrix

GSLB Methods

16

© 2013 Citrix

GSLB Methods

17

© 2013 Citrix

GSLB Methods

18

© 2013 Citrix

GSLB Sites

19

© 2013 Citrix

GSLB Sites

20

© 2013 Citrix

GSLB Sites

21

© 2013 Citrix

GSLB Service

22

© 2013 Citrix

Configuration Summary

23

© 2013 Citrix

Configuring Authoritative DNS - ADNS

© 2013 Citrix

GSLB Visualizer

25

© 2013 Citrix

Synchronizing Configuration

26

Each Netscaler needs one Local GSLB site and all the other Remote sites.

All sites need the same configuration.

There is a GSLB configuration synchronization option.

Customizing your GSLB Configuration

© 2013 Citrix

GSLB Load Balancing methods

28

The NetScaler GSLB methods: Round Trip Time (RTT)Static Proximity

© 2013 Citrix

Local DNS IP (LDNS)

29

IP address that is being tested against is not an actual client IP address

it is the nameserver that is resolving the IP address on behalf of the client.

We refer to this as the “LDNS” IP address for the client’s local DNS IP address.

© 2013 Citrix

GSLB Static Proximity

30

IP-address based static proximity database is a UNIX-based ASCII file.

© 2013 Citrix

GSLB Static Proximity Troubleshooting

31

nsmap -t –d

root@test# nsmap -t -dEnter IP address to to test (dot notation) or q to exit:

© 2013 Citrix

GSLB Static Proximity Troubleshooting

32

> show locationparameterStatic Proximity----------------Database mode: Not applicableFlushing: Idle; Loading: IdleContext: geographicQualifier 1 label: ContinentQualifier 2 label: CountryQualifier 3 label: RegionQualifier 4 label: CityQualifier 5 label: ISPQualifier 6 label: OrganizationLocation file (format: Not applicable): Not loadedLines: 0 Warnings: 0 Errors: 0Current static entries: 0 Current custom entries: 0 Done

© 2013 Citrix

GSLB Dynamic RTT

33

Dynamic RTT : measure from each “site” NetScaler to the remote LDNS

Three Monitors:Ping of IP address (LDNS-PING)DNS TCP probeDNS UDP query

Global Server Load BalancingPersistence

© 2013 Citrix

Persistence Based on Source IP

35

The GSLB virtual server is responsible for DNS-based site persistence, and it controls the site persistence

Persistence Table

All sites must use the same set of persistence identifiers on the GSLB virtual servers.

© 2013 Citrix

GSLB Persistence – Source IP Troubleshooting

36

© 2013 Citrix

GSLB Persistence – Source IP Troubleshooting

37

Global Server Load BalancingHTTP Cookie Persistence

© 2013 Citrix

Persistence Based on HTTP Cookies

39

HTTP-request level Connection proxy

HTTP redirect.

© 2013 Citrix

HTTP Connection Proxy

40

If the client gets sent to the wrong site:

The other site creates a connection to the GSLB site that inserted the site cookie, and proxies the client request

© 2013 Citrix

HTTP Connection Proxy

41

© 2013 Citrix

HTTP Redirect Persistence

42

Redirect persistence can be used only: For HTTP or HTTPS protocols. If the domain name in the request is a GSLB DomainWhen a backup VIP or a GSLB local service is DOWN

© 2013 Citrix

GSLB Persistence – HTTPRedirect

43

© 2013 Citrix

GSLB Persistence – HTTP Redirect

44

Global Server Load BalancingTroubleshooting

© 2013 Citrix

GSLB Troubleshooting

46

> sh gslb site

1) 10.217.245.104_siteB (10.217.245.104) Site Type: LOCAL

Metric exchange: ENABLED Public IP: 10.217.245.104

Network metric exchange: ENABLED Persistence session exchange: ENABLED

Trigger Monitors: ALWAYS

2) 10.217.147.70_siteA (10.217.147.70) Site Type: REMOTE

Metric exchange: ENABLED Site Metric MEP Status: DOWN Public IP: 10.217.147.70

Network metric exchange: ENABLED Persistence session exchange: ENABLED

Trigger Monitors: ALWAYS

© 2013 Citrix

GSLB Troubleshooting

47

> sh gslb vserver

1) www.example.com_gslbvs_b - HTTP State: UP

DNS Record Type: A

Last state change was at Thu Apr 11 22:17:28 2013

Time since last state change: 11 days, 23:01:56.670

Configured Method: LEASTCONNECTION

Current Method: Round Robin Reason: Bound service's state changed to UP

BackupMethod: ROUNDROBIN

No. of Bound Services : 2 (Total) 1 (Active)

Persistence: SOURCEIP

Persistence Mask: 255.255.255.255 Persistence v6MaskLength: 128

Persistence Timeout: 2 min Persistence ID: 2

Disable Primary Vserver on Down: DISABLED Site Persistence: ConnectionProxy

© 2013 Citrix

GSLB Troubleshooting

48

> sh gslb service1) 10.217.245.107_80_gslbsvc (10.217.245.107: 80)- HTTP Server: 10.217.245.107 State: UP

Effective State: UP

Max Conn: 0 Max Bandwidth: 0 kbits

PublicIP: 10.217.245.107 PublicPort: 80

Type: LOCAL Site Name: 10.217.245.104_siteB

Site Prefix: SiteB Site Persistence: ConnectionProxy

Threshold: BELOW Monitor Threshold : 0

2) 10.217.147.71_80_gslbsvc (10.217.147.71: 80)- HTTP Server: 10.217.147.71 State: DOWN

Effective State: DOWN

Max Conn: 0 Max Bandwidth: 0 kbits

PublicIP: 10.217.147.71 PublicPort: 80

Type: REMOTE Site Name: 10.217.147.70_siteA

Site Prefix: SiteA Client IP: DISABLED

Down state flush: DISABLED

Site Persistence: ConnectionProxy

Threshold: BELOW Monitor Threshold : 0

© 2013 Citrix

GSLB Troubleshooting

49

root@ns# nsconmsg -K newnslog -d stats | grep gslb

root@ns# nsconmsg -g glsb -d current -s disptime=1

© 2013 Citrix

Resources

50

http://support.citrix.com/proddocs/topic/netscaler-traffic-management-10-map/netscaler-gslb-gen-wrapper-10-con.html

http://support.citrix.com/article/CTX122619

http://support.citrix.com/article/CTX123976

Global Server Load Balancing

© 2013 Citrix

Before you leave…

52

•Conference surveys are available online at www.citrixsynergy.com starting Friday, May 24 at 9:00 a.m. PT

ᵒ Provide your feedback by 4:00 p.m. PT that day and you’ll receive a $30 Amazon.com gift card via email

•Download presentations starting Monday, June 3, from your My Conference Planning tool located within the My Account section

Work better. Live better.