GSLB - Global Server Load Balancing - When and Where to deploy
Load balancing is an integral part of Enterprise Architectures. Some of the huge benefits are:
- Scalability
- Bring High Availability to app's and aid in App uptime
- Which provide better user experience(s)
- Increase redundancy allow you to take resources offline for maintenance while continuing to service workloads on the other part of the HA pair.
- Limitation - ADC/LB typically only operate at the local data center level
Global Server Load Balancing (GSLB) takes these features to a 'geographic distributed level', across the world. GSLB refers to the intelligent distribution of traffic across server resources located in multiple geographies, creating a faster and more reliable user experience.
Top GSLB Design types
- GSLB direct to node(s)
- DNS delegation - create sub-domain such as gslb.company.com
- L7 SNAT (OSI Layer 7 Source NAT)
Gotcha - Don't overlook DNS propagation timelines. Always preplan your DNS changes and allow proper propagation times then perform your GSLB work.
Top Vendors offering GSLB solutions
- Akamai GTM (Global Traffic manager) is their cloud GSLB
- Cisco Systems GSS 4480
- Citrix NetScaler
- CloudFlare
- F5 BIG-IP GTM
- Fortinet FortiADC
- NGINX
Summary - ADC/LB and GSLB are both important to enterprise architectures and should be deployed based upon your requirements. Do you see a need to deploy GSLB in your enterprise?
