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Michaelyang's avatar
Michaelyang
Icon for Cirrostratus rankCirrostratus
Nov 28, 2022
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About Https monitor

Hello,

I would like to monitor servers that are

https://10.20.54.11
https://10.20.54.12 
https://10.20.54.13

I would like to monitor when the webpage is not available.
I checked the F5 file and it says I can set it up like this:

SEND: GET / HTTP/1.1\r\nHost: server.com\r\nConnection: close\r\n\r\n

RESPONSE: HTTP/1.1 200 OK

But since I am monitoring a pool and not a single server, how should I write nHost?
What do nHost and nConnection mean?

Any help would be appreciated!

application delivery
  • mihaic's avatar
    mihaic
    Nov 28, 2022

    Here is more info: https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-12-0-0/3.html#unique_666712253

    I would recommend not using just a simple GET , but GET index.html for example, or whatever you have on the webservers.

    Then if you want just to do a simple check you live it like it is : RESPONSE: HTTP/1.1 200 OK

    Or you can use Receive String to check for a specific word in the HTML reply. The text string can be regular text, HTML tags, or image names.

    Then you can use the Reverse setting to Yes, the monitor marks the pool, pool member, or node Down when the test is successful.

    As for the host part, it should be your web server domain name, like www.example.com.

    All your servers should have one and it should be the same.

    You attach this monitor to the pool, so all members in the pool will use it.

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  • mihaic's avatar
    mihaic
    Icon for MVP rankMVP
    Nov 28, 2022

    Here is more info: https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-monitors-reference-12-0-0/3.html#unique_666712253

    I would recommend not using just a simple GET , but GET index.html for example, or whatever you have on the webservers.

    Then if you want just to do a simple check you live it like it is : RESPONSE: HTTP/1.1 200 OK

    Or you can use Receive String to check for a specific word in the HTML reply. The text string can be regular text, HTML tags, or image names.

    Then you can use the Reverse setting to Yes, the monitor marks the pool, pool member, or node Down when the test is successful.

    As for the host part, it should be your web server domain name, like www.example.com.

    All your servers should have one and it should be the same.

    You attach this monitor to the pool, so all members in the pool will use it.

  • CA_Valli's avatar
    CA_Valli
    Icon for MVP rankMVP
    Nov 28, 2022

    HTTP 1.1 request typically includes request headers that you should specify, this is why you should configure your monitor with this syntax. 

    > GET /path/to/test.html HTTP 1.1  # request line
> Host: www.test.com    # first request header. it's on a new line - simulated by \r\n syntax.
> Connection: close     # another request header, again on new line
>                       # a blank line (\r\n twice) separates header from body
> ID12345&user          # request body (optional)

    Monitor syntax to simulate this^ request will be:

    GET /path/to/test.thml HTTP1.1\r\nHost: www.test.com\r\nConnection: close\r\n\r\n