Forum Discussion
Kibao_130897
Nimbostratus
NimbostratusFailover Configuration Between Datacenter and Data Recovery Center using F5 BIG-IP GTM Feature
I want to deploy the F5 BIG-IP 6900 GTM to do fail over between DC and DRC. Traffics from remote site usually go to the DC. When the DC/services at the DC is down, LoadBalancers should automatically ...
Jason_40733
Cirrocumulus
CirrocumulusThe GTM feature uses DNS to re-direct traffic. You can set it up to monitor health of the servers behind it. You can also have it set one set of servers as the primary, and the other as backup.
You'll need to tune your DNS record TTL appropriately though. If you go with a 24 hour TTL of 86400... the GTMs would immediately start serving out the Data Recovery Center IP address right away when the Data Center is unavailable, but anyone that has connected will have the old IP address cached for the next 24 hours. If you tune your DNS TTL down to 0... you'll be serving out the IP address from your GTM's on every single request. This is doable, but doesn't scale for large environments.
Jason
Kibao_130897Thanks Very Much Jason, What do you mean when you say large environments? We have 214 sites and each site has around 20 users. Will this solution work perfect with our infrastructure? Saidi- Jason_40733Turning your DNS TTL for things being load balanced by GTM means that every connection from every client will always do a DNS lookup. If you have a very busy application or one that does not make use of persistent connections you can flood your GTMs with DNS requests by setting the TTL to 0. Determining an acceptable amount of "lag" between switching from a failed primary to a backup and then setting your DNS TTL appropriately is advised. I've had some applications that useda 300 second TTL, and some that used a 10 second TTL. Jason
