Navigating F5:

• You might have a front url and want to know what instances it’s being load-balanced across, or you might have an instance and want to know which load-balanced pool it’s in. Scroll down if you’re starting from an instance.

• IF YOU HAVE A URL:

  • If you have a url and you want to know whether it’s load balanced behind the scenes:

  • For instance, http://graphitegcp.acmecorp.com/

  • First run dig graphitegcp.acmecorp.com

    • If it’s just a CNAME pointing to another DNS, do the same on the new DNS

    • (If that DNS is an internal one though, eg eventinator01.ab2.acme.com, then your trail has run cold and you know this url is NOT load balanced)

  • The dig command tells you that graphitegcp.acmecorp.com is pointing at 10.96.253.55

  • So we go to F5 and select Local Traffic | Virtual Servers on the left. Then we search for 10.96.253.55

  • This takes us to a vip (aka virtual server) called vip_gcp_graphite-frontrelay_0

  • Click through to the vip and click on the Resources tab - this tells you that the default pool is pool_gcp_carbonrelay_2003

    • NB: More than one vip can use the same pool

  • Select pools on the left and search for that pool (pool_gcp_carbonrelay_2003) - click through

  • Select the Members tab for the pool, and you’ll see which instances are in that pool

  • Basically the VIP is the front door - people hitting that IP address will actually get their requests load-balanced across all the nodes in the pool

• IF YOU HAVE AN INSTANCE:

  • If you have an instance and want to know what pool it’s in:

  • Scroll down to Nodes on the left, and search for either the IP address or the DNS of your instance