Application Delivery (ADX)

Reply
Contributor
Posts: 39
Registered: ‎05-04-2009

Health Check Q: How do I link the health of a real server on the health check status of another device or service using ServerIrons?

Health Check Q: How do I link the health of a real server on the health check status of another device or service using ServerIrons?

I do have a web server and I would like to ensure the web server is going down in case another backend web server is going down. Is this possible?

Thx for your help.

Super Contributor
Posts: 316
Registered: ‎05-01-2009

Re: Health Check Q: How do I link the health of a real server on the health check status of another device or service using ServerIrons?

I guess you would like to do the following:

both real server do have a web server installed and you would like to ensure that the front end web server is going down in two cases:

1st: the frontend web server itself is going down

2nd: the backend web server is going down

Is this correct?

If so my suggestion would be the following:

Create to healtck's - one for the frontend and one for the backend server. This would look like:

healthck frontend tcp

  dest-ip  192.168.101.101

  port  80

  protocol  http

  protocol http  url "GET /"

  l7-check


healthck backend tcp

dest-ip 192.168.101.102

port  80

protocol http

protocol http url "GET /"

l7-check

Create a combined healthck (it is called boolean health check policy):

healthck both boolean

  and frontend backend

The frontend healthck is only TRUE/successful in case the real server 192.168.101.101 is getting health checked successfully. Same for the backend one. The "both" healthck is only TRUE/sucessful in case the frontend one AND the backend one is TRUE/successful.

Bind the combined one to the frontend server and the backend one to the backend server:

server real frontend 192.168.101.101

  port 80 healthck both


server real backend 192.168.101.102

  port 80 healthck backend

and you do have what you want.

At least I hope so.

Contributor
Posts: 39
Registered: ‎05-04-2009

Re: Health Check Q: How do I link the health of a real server on the health check status of another device or service using ServerIrons?

I am going to try this but I do not get how to check the reply from the real servers - I would like to look into the actual HTTP reply. The real servers need to respond with a special string otherwise they are not really up and running. Ideas?

Super Contributor
Posts: 316
Registered: ‎05-01-2009

Re: Health Check Q: How do I link the health of a real server on the health check status of another device or service using ServerIrons?

My example does not fit 100% to this requirement - you do need to configure so called match-lists on top of the stuff above.

Let me use an example again: the backend web server needs to respond with "IamFEELINGgood" to be up and running.

Add the following to the example above:

http  match-list web-ok

default down

up  simple "IamFEELINGgood”

healthck backend tcp

dest-ip 192.168.101.102

port  80

protocol http

protocol http url "GET /"

protocol http content-match web-ok

l7-check

Feel free to change the query to something else than "GET /" in case you would like to request a special page. Happy now?

Join the Community

Get quick and easy access to valuable resource designed to help you manage your Brocade Network.

vADC is now Pulse Secure
Download FREE NVMe eBook