Rate limiting and budget controls in Agentic AI - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Rate Limiting Purpose

Why is rate limiting important in managing AI agent requests?

A To reduce the accuracy of AI model predictions intentionally

B To allow unlimited requests without any restrictions

C To prevent system overload by controlling the number of requests in a time frame

D To increase the speed of all incoming requests simultaneously

💡 Hint

Think about what happens if too many requests come at once.

Rate limiting helps avoid system crashes by limiting how many requests can be processed in a given time.

❓ Model Choice

intermediate

Choosing a Budget Control Strategy

You want to limit the total compute cost of AI agent calls over a month. Which budget control method is best?

A Set a fixed maximum number of API calls allowed per month

B Disable rate limiting and monitor usage manually

C Allow unlimited calls but slow down the response time

D Increase the model size to reduce calls

💡 Hint

Think about how to keep costs predictable.

Setting a fixed maximum number of calls directly controls usage and cost.

❓ Predict Output

advanced

Output of Rate Limiting Code Snippet

What is the output of this Python code simulating a simple rate limiter?

Agentic AI

import time

class RateLimiter:
    def __init__(self, max_calls, period):
        self.max_calls = max_calls
        self.period = period
        self.calls = []

    def allow(self):
        current = time.time()
        self.calls = [call for call in self.calls if call > current - self.period]
        if len(self.calls) < self.max_calls:
            self.calls.append(current)
            return True
        return False

limiter = RateLimiter(3, 5)
results = []
for _ in range(5):
    results.append(limiter.allow())
    time.sleep(1)
print(results)

A [False, False, False, False, False]

B [True, True, True, True, True]

C [True, False, True, False, True]

D [True, True, True, False, False]

💡 Hint

Consider how many calls are allowed within the 5-second window.

The limiter allows 3 calls in 5 seconds. The first 3 calls return True, the next 2 return False.

❓ Metrics

advanced

Interpreting Budget Control Metrics

You have a budget control system that tracks 'calls_used' and 'calls_remaining'. If calls_used = 750 and calls_remaining = 250, what is the total budget and percentage used?

A Total budget is 1000 calls; 75% used

B Total budget is 1000 calls; 25% used

C Total budget is 500 calls; 150% used

D Total budget is 1000 calls; 50% used

💡 Hint

Add used and remaining calls to find total, then calculate percentage.

Total budget = calls_used + calls_remaining = 1000. Percentage used = (750/1000)*100 = 75%.

🔧 Debug

expert

Debugging Budget Control Logic

Given this budget control snippet, what error will occur when running it?

Agentic AI

class BudgetControl:
    def __init__(self, max_calls):
        self.max_calls = max_calls
        self.calls_made = 0

    def make_call(self):
        if self.calls_made < self.max_calls:
            self.calls_made += 1
            return True
        else:
            return False

budget = BudgetControl(3)
results = [budget.make_call() for _ in range(5)]
print(results)
print(budget.calls_remaining)

A IndexError: list index out of range

B AttributeError: 'BudgetControl' object has no attribute 'calls_remaining'

C TypeError: unsupported operand type(s) for +: 'int' and 'str'

D No error; output is [True, True, True, False, False]

💡 Hint

Check if all attributes used are defined in the class.

The class does not define 'calls_remaining', so accessing it causes AttributeError.

Practice

1. What is the main purpose of rate limiting in an AI system?

easy

A. To control how often users can make requests

B. To increase the speed of AI responses

C. To improve the accuracy of AI predictions

D. To store more user data for training

Solution

1. Step 1: Understand rate limiting concept

   Rate limiting is about controlling the number of requests a user can make in a time period.

2. Step 2: Identify the main purpose

   This control helps prevent overload and keeps the system fair for all users.

3. Final Answer:

   To control how often users can make requests -> Option A

4. Quick Check:

   Rate limiting = control request frequency [OK]

Hint: Rate limiting means limiting request frequency [OK]

Common Mistakes:

• Confusing rate limiting with improving AI accuracy
• Thinking rate limiting increases speed
• Mixing rate limiting with data storage

2. Which of the following is the correct way to set a budget control in an AI usage system?

easy

A. budget = max(1000)

B. limit_budget = 'max 1000 dollars'

C. setBudget(1000 dollars)

D. budget_limit = 1000 # sets max money allowed

Solution

1. Step 1: Identify correct syntax for budget control

   Setting a budget limit usually involves assigning a numeric value to a variable representing money allowed.

2. Step 2: Check each option

   budget_limit = 1000 # sets max money allowed uses a clear assignment with a comment, which is correct syntax. Others use invalid syntax or unclear expressions.

3. Final Answer:

   budget_limit = 1000 # sets max money allowed -> Option D

4. Quick Check:

   Assign numeric budget limit = correct [OK]

Hint: Budget control is a numeric variable assignment [OK]

Common Mistakes:

• Using strings instead of numbers for budget
• Calling undefined functions like setBudget
• Using incorrect syntax like max(1000)

3. Given this code snippet controlling requests per minute:

requests = [1,1,1,1,1,1]
limit = 5
allowed = sum(requests[:limit])
print(allowed)

What will be the printed output?

medium

A. 1

B. 6

C. 5

D. Error

Solution

1. Step 1: Understand the code slicing and summing

   The code sums the first 5 elements of the list requests, each element is 1.

2. Step 2: Calculate the sum of first 5 elements

   Sum = 1+1+1+1+1 = 5

3. Final Answer:

   5 -> Option C

4. Quick Check:

   Sum first 5 ones = 5 [OK]

Hint: Sum first 5 elements of ones list = 5 [OK]

Common Mistakes:

• Summing all 6 elements instead of 5
• Confusing slicing syntax
• Expecting an error due to slicing

4. Find the error in this rate limiting code snippet:

max_requests = 10
requests_made = 0
if requests_made > max_requests:
    print("Limit reached")
else:
    requests_made += 1
    print("Request allowed")

medium

A. No error, code is correct

B. The condition should be >= instead of >

C. The print statements are reversed

D. requests_made should start at 1

Solution

1. Step 1: Analyze the condition for rate limiting

   The code blocks requests if requests_made is greater than max_requests, but it should block when equal too.

2. Step 2: Correct the condition

   Change > to >= to include the max_requests limit properly.

3. Final Answer:

   The condition should be >= instead of > -> Option B

4. Quick Check:

   Use >= to block at limit [OK]

Hint: Use >= to block requests at limit [OK]

Common Mistakes:

• Using > misses blocking at exact limit
• Starting requests_made at 1 is unnecessary
• Swapping print messages confuses logic

5. You want to limit AI usage to 1000 requests per day and a budget of $500. Which approach correctly combines rate limiting and budget control?

hard

A. Set daily_limit = 1000 and budget_limit = 500; check both before allowing requests

B. Set daily_limit = 1000; budget_limit is not needed if rate limiting is set

C. Only set budget_limit = 500; rate limiting is handled automatically

D. Set budget_limit = 1000 and daily_limit = 500; swap values for safety

Solution

1. Step 1: Understand the need for both controls

   Rate limiting controls request count; budget controls money spent. Both must be checked.

2. Step 2: Evaluate options for combining controls

   Set daily_limit = 1000 and budget_limit = 500; check both before allowing requests correctly sets both limits and checks them before allowing requests. Others ignore one control or swap values incorrectly.

3. Final Answer:

   Set daily_limit = 1000 and budget_limit = 500; check both before allowing requests -> Option A

4. Quick Check:

   Use both limits together for control [OK]

Hint: Always check both request count and budget before allowing [OK]

Common Mistakes:

• Ignoring budget when rate limiting is set
• Assuming budget controls requests automatically
• Swapping limit values causing confusion