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AX handling of Connection Limit
Hello
I've been looking into making our AX3030 handle max connections towards our appservers so it doesn't let it overload the appservers and I can't find much info on how it handles connection limits and how we can fine tune it.
First, I'd like a definition on Connection Limit, is it the amount of http requests? Another issue I have is that at this writing moment don't know the exact number of connections our appservers can handle, I'm still waiting on that figure from our devs.
My second area of concern is the handling of connections once the limit has been hit. I tried setting it to a low number and all I got was a no connection page. I would like to be able to handle what the AX does with connections after the limit (other than setting the resume limit), like showing a sorrypage ("We're overloaded, please come back later") or perhaps having a queue (short) of some sort (tcserver/tomcat has one) and when that limit is hit show the sorrypage.
I can't find anything about it in the manuals or by looking around in the settings. Is it perhaps something that require aflex?
Seems like a basic thing to do (on max load show sorry page until apps can accept new connections), anyone have a solution?
I've been looking into making our AX3030 handle max connections towards our appservers so it doesn't let it overload the appservers and I can't find much info on how it handles connection limits and how we can fine tune it.
First, I'd like a definition on Connection Limit, is it the amount of http requests? Another issue I have is that at this writing moment don't know the exact number of connections our appservers can handle, I'm still waiting on that figure from our devs.
My second area of concern is the handling of connections once the limit has been hit. I tried setting it to a low number and all I got was a no connection page. I would like to be able to handle what the AX does with connections after the limit (other than setting the resume limit), like showing a sorrypage ("We're overloaded, please come back later") or perhaps having a queue (short) of some sort (tcserver/tomcat has one) and when that limit is hit show the sorrypage.
I can't find anything about it in the manuals or by looking around in the settings. Is it perhaps something that require aflex?
Seems like a basic thing to do (on max load show sorry page until apps can accept new connections), anyone have a solution?
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>First, I’d like a definition on Connection Limit, is it the amount of http requests?
The term "Connection Limit" is for layer 4 TCP sessions.
It is possible to have multiple http requests over 1 TCP session, so your case:
>I tried setting it to a low number and all I got was a no connection page.
May be your HTTP requests were sent over few TCP sessions which was lower than the number you configured as connection limit.
You can check the number of the connections by using commands like "show slb virtual-server".
Some aFleX script like below can check the number of TCP connections to VIP (myVIP), and if the current connection is over 100, let the client to be redirected to different site.
############Sample START
when CLIENT_ACCEPTED {
set CurrentConn [STATS::get virtual-server myVIP current-connection]
}
when HTTP_REQUEST {
if { $CurrentConn > 100 } {
HTTP::redirect "http://siteunavailable.mysite.com"
}
}
############Sample END
If you need to reply back to the client in case of connection overflow (rather than redirect), then you can change "HTTP::redirect" to "HTTP::respond".
Just in case, I am attaching the same sample script file.
Hope this helps.
when HTTP_REQUEST {
if { $CurrentConn > 100 } {
THE HTTP:RESPONSE FROM OTHER POST HERE
}
}
Thanks
Michael.