Microsoft Exam PL-400 Topic 4 Question 124 Discussion

Scenario: User2 reports that Azure consumption for API calls has increased significantly to 100 calls per minute in the last month.

Example:

In the following example, the rate limit of 10 calls per 60 seconds is keyed by the caller IP address. After each

policy execution, the remaining calls allowed in the time period are stored in the variable remainingCallsPerIP.

<inbound>

<base />

<rate-limit-by-key calls='10'

renewal-period='60'

increment-condition='@(context.Response.StatusCode == 200)'

counter-key='@(context.Request.IpAddress)'

remaining-calls-variable-name='remainingCallsPerIP'/>

</inbound>

<outbound>

<base />

</outbound>

Note: The rate-limit-by-key policy prevents API usage spikes on a per key basis by limiting the call rate to a

specified number per a specified time period. The key can have an arbitrary string value and is typically

provided using a policy expression. Optional increment condition can be added to specify which requests

should be counted towards the limit. When this call rate is exceeded, the caller receives a 429 Too Many

Requests response status code.

Incorrect Answers:

A: With renewal-period='30' 200 calls/minute would be allowed.

B: This would increase the calls/minute limit to 1000.

https://docs.microsoft.com/en-us/azure/api-management/api-management-access-restriction-policies