We are having issues with our active standby configuration related to our F5. The F5 is configured to point to node 1. But in the instructions I can’t find anything that indicates how to configure node 2 to Stand by.
Release : 6.9+
Component : High Availability
Latest (as of this writing) product guide:
The product documentation has a handful of steps. Three of those steps describe how you go about setting up the environment to have an active-standby high availability CDD service. Those three steps are:
#2 and #3 are the focus for this article. Specifically as it relates to F5. The product documentation gives an example haproxy.cfg configuration. Information for nginx.c #1 is out of scope for this article.
Configure LB to send all traffic to active cdd server
F5's have pools. A pool is a logical set of devices, such as web servers, that you group together to receive and process traffic. This is straight from the F5 website which explains pools and their features really well. You can view it here: https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-basics-11-6-0/4.html
Let's get started...
Different "Priority Group" values (10 and 5) is how we distribute 100% of the traffic to the active server and 0% traffic to the standby server since lower priority groups only receive traffic when all members in higher priority groups are unavailable.
The objective here is to send 100% of CDD traffic to the active cdd server. None of the traffic should go to the standby cdd server. That would be an Active-Active HA setup which CDD does support. See the product documentation for additional details. F5 setup for active active is out of scope for this document.
Configure LB to use a specific http monitor to test CDD server availability
Using a monitor is how the BIG-IP system determines whether the members of the pool are available or unavailable. It determines if traffic should get sent to the member with the priority group value of 5. If the member with a priority group value or 10 stops responding to the health check then it should begin sending traffic to the member with a priority group value of 5. The default http "Health Monitor", set in the properties of the Pool, is a bare minimum. It is recommended to use a custom http monitor to test the URI mentioned in the CDD product document. Validated steps for setting up a custom http health monitor are not available at this time. However, this URL may help: LTM: HTTP Monitoring with POST request