Warning message on ACE

Question

Hello expert,
I'm just wondering whether we can set a maximum number of incoming connections on ACE?
In such a way, if the limit is reached, users who still trying to access the website will be prompted with some kind of warning message. like
"system is busy, try again later"
please let me know. Thanks.
Sincerely,
Andrew

Answer 1

Hello Andrew,
Mmm, maybe you can take a look of this link:
http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/vA5_1_0/command/reference/rsrce.html
Perhaps you can assign some specific resources for connections but it will be good to check this your Cisco SE.
On the rserver level, we have the following:
Configuring Real Server Connection Limits
To prevent a real server from being overburdened, you can limit the  maximum number of active connections to the server. You can set the  maximum and minimum connection thresholds by using the conn-limit command in either real server host or real server redirect configuration mode. The syntax of this command is as follows:
conn-limit max maxconns min minconns
The keywords and arguments are as follows:
•max maxconns—Specifies the maximum allowable number of active connections to a real server. When the number of connections exceeds the maxconns threshold value, the ACE stops sending connections to the real server  and assigns the real server a state of OUTOFSERVICE until the number of  connections falls below the configured minconns value. Enter an integer from 2 to 4294967295. The default is 4294967295.
•min minconns—Specifies  the minimum number of connections that the number of connections must  fall below before sending more connections to a server after it has  exceeded the maximum connections threshold. Enter an integer from 2 to  429496729. The default is 4294967295. The minconns value must be less than or equal to the maxconns value.
Obviously the ACE cannot send messages like that, you can combine perhaps the configuration above with a backup serverfarm or something like that.
Do not hesitate to let us know your feedback and mark it if it is useful for you
Hope these details help.
Jorge