Product Documentation

Configuring a Traffic Rate Limit Identifier

Sep 23, 2014

A rate limit identifier returns a Boolean TRUE if the amount of traffic exceeds a numeric limit within a particular time interval. The rate limit identifier definition can optionally include a stream selector. When you include a limit identifier in the compound default syntax expression in a policy rule, if you do not specify a stream selector, the limit identifier is applied to all the requests or responses that are identified by the compound expression.

Note: The maximum length for storing string results of selectors (for example, HTTP.REQ.URL) is 60 characters. If the string (for example, URL) is 1000 characters long, of which 50 characters are enough to uniquely identify a string, use an expression to extract only the required 50 characters.

To configure a traffic limit identifier from the command line interface

At the command prompt, type:

add ns limitIdentifier <limitIdentifier> -threshold <positive_integer> -timeSlice <positive_integer> -mode <mode> -limitType ( BURSTY | SMOOTH ) -selectorName <string> -maxBandwidth <positive_integer> -trapsInTimeSlice <positive_integer>


Configuring traffic rate limit identifier in BURSTY mode:

> add ns limitIdentifier 100_request_limit -threshold 100 -timeSlice 1000 -mode REQUEST_RATE -limitType BURSTY -selectorName limit_100_requests_selector -trapsInTimeSlice 30

Configuring traffic rate limit identifier in SMOOTH mode:

> add ns limitidentifier limit_req -mode request_rate -limitType smooth -timeslice 1000 -Threshold 2000 -trapsInTimeSlice 200

To configure a traffic limit identifier by using the configuration utility

Navigate to AppExpert > Rate Limiting > Limit Identifiers, click Add and specify the relevant details.