Intel 7190 manual Multi-Site Traffic Management Using Intel Load Balancers

C H A P T E R 2 Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Multi-Site

Traffic

Management

Using Intel

Load

Balancers

4.The client DNS server sends a query to the mstd-ex.comAuthoritative DNS server to resolve www.mstd-ex.com.

5.The Authoritative DNS server responds to the client DNS server with the IP address of www.mstd-ex.com.

6.The client DNS server responds to the client with the IP address of www.mstd-ex.com.

In the discussion above, the 7190 acts as authoritative DNS server for zone.mstd-ex.com,which is the zone in which the name www.mstd- ex.com resides.

Multi-site load balancing solves most of the problems inherent in Round Robin DNS. Under the server load balancing model, servers are aggregated in a “server farm” behind a load balancer known by a Virtual IP address or “service.” (The service is the IP address of which the external network is aware.) By keeping track of such metrics as number of connections, which services are running, response time and the like, the load balancer knows the status of the servers. The 7190 retrieves metrics from the load balancer. Thus, when a client requests the service, the 7190 routes it to the site who has a server best able to fulfill it.

If the data center has an Intel Load Balancer, the 7190 works in concert with the “agents” in the load balancers by continually communicating with each site’s agent through site verification protocol. This keeps the 7190 informed of the following:

•Health of the load balancers.

•Individual service health and availability.

•CPU utilization of load balancers (as of 7140/7170, 7180 Software release 2.2.1)

•Response time for each service (as of 7140/7170, and 7180 software release 2.3)

•Number of connections to each load balancers (as of 7140/7170, and 7180 software release 2.2.1)

Site verification protocol information is encrypted for secure communication between an Intel Load Balancer and the 7190.

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