# Reject client-side request

The Page Rules drop-down list contains a variety of classified actions. One of them is “Request Limiting Action”,and the action is used to control requests. The following is an introduction to how to block a request, or Reject Request:

The main rationale behind Block Request lies in the View Window setting. If, in all continuous view windows,

the client-side exceeds the set block threshold, 503 Error will then be returned to the client-side within the designated time limit.

Control requests via the parameters below:

  1. Key Word: The default option is the IP address from the terminal, and the drop-down box offers other options, i.e. URI, URI Parameter or Cookie.

Selecting URI Parameter or Cookie requires one more corresponding Argument field to be specified;

  1. Adjust Rate: Requests with a lower rate will not encounter any restriction; requests with a rate higher than this level but lower than the Reject Rate level will experience delayed execution;

  2. Reject Rate: Requests with a higher rate will be rejected, with 503 http status code directly returned to the terminal.

Both Adjust Rate and Reject Rate are based on Request Per Second by default, but Request Per Minute is an optional unit.

If the two parameters have the same value, requests exceeding the set value will be rejected directly, without any delay for buffer.

  1. Time Window: The size of the view time window;

  2. Block Threshold: The number of continuously appearing view time window;

  3. Block Time: Designated block time. Beyond the time, the client side will get unblocked, and Block Threshold will start counting anew.

Click the Create button on the bottom right-hand side, and rule is set successfully. The current page will then automatically jump back to the Page Rules page.