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Forum Discussion

walkman69's avatar
walkman69
Icon for Altostratus rankAltostratus
Mar 25, 2024
Solved

URL Distribution

I received a request as to the possibility to or distribute traffic for one url to multiple urls (round-robin, least connections, or even just randomly ) but never exceed 50 connections to each one. ...
application delivery
  • JRahm's avatar
    JRahm
    Mar 26, 2024

    Not at all tested or optimized or secured against injection with the table commands, but to get the juices flowing I threw this together. Not 100% confident it'll work and I don't have time until end of the week to flesh out and test, but it is possible to achieve what you're after. That said, it'll be a support nightmare to grow with the needs of the business since it's not a well-defined problem or scale, so I would push back against this particular ask.

    when HTTP_REQUEST priority 500 {
    if { [string tolower [HTTP::path]] == "/form"} {
        foreach form [list form1 form2 form3 form4 form5 form6] {
            if { [table lookup $form] < 50 } {
                table incr $form 1
                HTTP::uri /$form
                set current_form $form
                break
            }
        }
    }
}
when HTTP_REQUEST priority 501 {
    if { [string tolower [HTTP::path]] == "/form" } {
        HTTP::respond 429 content "<html><body><p>All forms at max of 50 requests</p></body></html>" 
    }
}
when HTTP_RESPONSE {
    table incr $current_form -1
}

     

Daniel_Wolf's avatar
Daniel_Wolf
Icon for MVP rankMVP
Mar 26, 2024

Hi walkman69,

I am randomly guessing, that each form1-6 is server by a different pool member. If my assumption is right, you can set a session limit per node and use Least Connections method for load balancing.

root@(awaf)(cfg-sync Standalone)(Active)(/Common)(tmos)# list ltm node 10.0.2.50 
ltm node 10.0.2.50 {
    address 10.0.2.50
    connection-limit 50
}

Then I would do the URL rewriting on the web server in the backend. Doing application logic on the BIG-IP is possible, but sometimes it's just... meh... Uti, non abuti.

Maybe you can explain your requirements a bit more in details, so we can suggest a better solution.

KR
Daniel

 

walkman69's avatar
walkman69
Icon for Altostratus rankAltostratus
Mar 26, 2024

Hi Daniel_Wolf! This is not node/member specific. All forms will reside on all servers in the same pool(s) and those servers it is just this one particular form/webpage that needs this type of distribution as the servers also handle traffic for other websites, so the connection limit cannot be set on a node basis. I definitely agree this is something that should be done on the web server itself, the dev team just wants to explore all options.