Configuring GSLB
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Tenant-A wishes to leverage the GSLB service provided by the xyztelco cloud. Tenant-A configures
a GSLB rule to load balance traffic across virtual server 1 at Zone-1 and virtual server 2 at Zone-2.
The domain name is provided as A.xyztelco.com. CloudPlatform orchestrates setting up GSLB virtual
server 1 on the GSLB service provider at Zone-1. CloudPlatform binds virtual server 1 of Zone-1
and virtual server 2 of Zone-2 to GLSB virtual server 1. GSLB virtual server 1 is configured to start
monitoring the health of virtual server 1 and 2 in Zone-1. CloudPlatform will also orchestrate setting up
GSLB virtual server 2 on GSLB service provider at Zone-2. CloudPlatform will bind virtual server 1 of
Zone-1 and virtual server 2 of Zone-2 to GLSB virtual server 2. GSLB virtual server 2 is configured to
start monitoring the health of virtual server 1 and 2. CloudPlatform will bind the domain A.xyztelco.com
to both the GSLB virtual server 1 and 2. At this point, Tenant-A service will be globally reachable at
A.xyztelco.com. The private DNS server for the domain xyztelcom.com is configured by the admin
out-of-band to resolve the domain A.xyztelco.com to the GSLB providers at both the zones, which are
configured as ADNS for the domain A.xyztelco.com. A client when sends a DNS request to resolve
A.xyztelcom.com, will eventually get DNS delegation to the address of GSLB providers at zone 1 and
2. A client DNS request will be received by the GSLB provider. The GSLB provider, depending on the
domain for which it needs to resolve, will pick up the GSLB virtual server associated with the domain.
Depending on the health of the virtual servers being load balanced, DNS request for the domain will
be resolved to the public IP associated with the selected virtual server.
16.9.2. Configuring GSLB
A GSLB deployment is the logical collection of GSLB virtual server, GSLB service, LB virtual server,
service, domain, and ADNS service. To create a GSLB site, you must configure load balancing in the
zone. You must create GSLB servers and GSLB services for each site. You must bind GSLB services
to GSLB servers. You must then create an ADNS service that provides the IP address of the best
performing site to the client's request. A GSLB server is an entity that performs load balancing for
the domains bound to it by returning the IP address of the best GSLB service. A GSLB service is a
representation of the load balancing/content switching server. An LB server load balances incoming
traffic by identifying the best server, then directs traffic to the corresponding service. It can also load-
balance external DNS name servers. Services are entities that represent the servers. The domain is
the domain name for which the system is the authoritative DNS server. By creating an ADNS service,
the system can be configured as an authoritative DNS server.