Cache-aside pattern in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Cache-aside Pattern Behavior

In the cache-aside pattern, what happens when a requested data item is not found in the cache?

A The cache deletes all stored data and forces a full reload.

B The cache automatically retrieves the data from the database and updates itself without application involvement.

C The application returns an error immediately without checking the database.

D The application fetches the data from the database, stores it in the cache, then returns it.

💡 Hint

Think about who controls the data retrieval and cache update in this pattern.

In the cache-aside pattern, the application checks the cache first. If data is missing, it fetches from the database, updates the cache, then returns the data.

❓ Architecture

intermediate

Cache-aside Pattern in Azure Architecture

You want to implement the cache-aside pattern using Azure services. Which combination best fits this pattern?

A Azure SQL Database pushes updates directly to Azure Cache for Redis without application intervention.

B Azure Cache for Redis automatically syncs with Azure SQL Database without application code.

C Azure App Service reads from Azure Cache for Redis; on cache miss, it queries Azure SQL Database and updates the cache.

D Azure App Service writes data only to Azure Cache for Redis and never to Azure SQL Database.

💡 Hint

Remember who controls cache updates in cache-aside pattern.

The application (Azure App Service) controls cache reads and writes. On cache miss, it queries the database and updates the cache.

❓ service_behavior

advanced

Cache Expiration Impact in Cache-aside Pattern

In a cache-aside pattern, if cached data expires, what is the expected behavior when the application requests that data again?

A The cache automatically refreshes expired data without application involvement.

B The application detects the cache miss, fetches fresh data from the database, updates the cache, and returns the data.

C The application returns stale data from the expired cache entry.

D The application throws an error because the cache entry is missing.

💡 Hint

Consider how cache expiration affects data retrieval in cache-aside.

When cached data expires, the application treats it as a cache miss, fetches fresh data from the database, updates the cache, and returns the data.

❓ security

advanced

Securing Cache Access in Cache-aside Pattern

Which practice best secures access to Azure Cache for Redis in a cache-aside pattern implementation?

A Use Azure Managed Identity for the application to authenticate securely to Azure Cache for Redis.

B Embed cache access keys directly in application code for faster access.

C Allow public network access to Azure Cache for Redis without firewall restrictions.

D Disable SSL/TLS encryption between the application and Azure Cache for Redis to improve performance.

💡 Hint

Think about secure authentication methods recommended by Azure.

Using Azure Managed Identity allows secure, keyless authentication to Azure Cache for Redis, improving security.

✅ Best Practice

expert

Optimizing Cache-aside Pattern for High Throughput

You have a high-traffic Azure App Service using cache-aside with Azure Cache for Redis and Azure SQL Database. Which approach best reduces database load while keeping data fresh?

A Implement a short cache expiration time and use background refresh to update cache proactively.

B Set cache expiration to a very long time and never refresh until manual cache clear.

C Disable cache expiration and rely on database queries for every request.

D Remove cache and query the database directly to avoid stale data.

💡 Hint

Consider balancing freshness and load reduction.

Short expiration with background refresh keeps cache fresh and reduces database load by avoiding frequent misses.