Forum Discussion

Michaelyang's avatar
Michaelyang
Icon for Cirrostratus rankCirrostratus
Oct 05, 2022

syntax for simple http monitor

Hello, I am trying to create an http monitor and Send String is HEAD / HTTP/1.1 I want this string will accept HTTP status codes of 200 and 401. Any error codes (ie: 4xx and 5xx) will cause the r...
application delivery
  • xuwen's avatar
    xuwen
    Oct 05, 2022

    use this linux bash to watch the pool member http response:

    echo -e "HEAD / HTTP/1.1" | nc 192.168.10.11 80

    and you Send String use HTTP/1.1, some web server maybe require you bring http Host Header,chang to this:

    firstly use echo -e "HEAD / HTTP/1.0\r\nConnection: close\r\n\r\n" | nc 192.168.10.11 80

    to watch the pool member response

    Send String is HEAD / HTTP/1.0\r\nConnection: close\r\n\r\n

    Receive String is HTTP/1\.(0|1) (200|401)

     

Michaelyang's avatar
Michaelyang
Icon for Cirrostratus rankCirrostratus

Hello Xuwen,

Thanks for your reply
I have some questions to ask you
Why Send String is "HEAD / HTTP/1.0\r\nConnection: close\r\n\r\n"
not "HEAD / HTTP/1.1\r\nConnection: close\r\n\r\n"

xuwen's avatar
xuwen
Icon for Cumulonimbus rankCumulonimbus
Oct 05, 2022

According to the protocol, HTTP/1.1 requires that the request header should bring a Host Header(some web servers can be compatible with HTTP/1.1 requests without a Host, and some will return a 40X status code), while HTTP/1.0 does not require mandatory carrying of a Host. The web server code should be compatible with HTTP/1.0 requests. The Send String in the built-in http monitor cannot carry a $1 variable instead of node ip when your pool have more than two pool members, You can also use external monitor and curl in the Linux shell to detect

Bigip has a Linux shell template located in System ›› File Management: External Monitor Program File List ›› sample_ Monitor, you can use it after a little modification