Another quick F5 related post:

Below is a neat little GET request that can be used in a F5 monitor to check the contents of a text file (or if it even exists) and degrade the performance of pool members if it doesnt. This could be useful for a Maintenance mode/Sorry site monitor for when a deployment is triggered.

To create the monitor:

1. Create a new monitor from Local Traffic -> Monitors; Give it a name and a description
2. Set Monitor type to HTTP
3. Specify the interval times you require
4. In the Send String Simply swap “/testfile.txt”  for your own text file name and “nlb.resdevops.com” in the example below for the target website the monitor will query for said text file.
   GET /testfile.txt HTTP/1.1\r\nHost: nlb.resdevops.com\r\nConnection:close\r\n\r\n
5. In the  Receive String enter the contents of your text file
6. Save it and apply the monitor to a Pool

Remember: The F5 must be able to resolve the host in the above query (you will need correct DNS/Gateway information set)

-Patrick