Cache-aside pattern in HLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to describe the first step in the cache-aside pattern.

HLD

When a request comes in, the system first checks the [1] for the data.

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Adatabase

Bnetwork

Ccache

Dfilesystem

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing cache with database as the first data source.

Assuming data is fetched directly from the network.

The cache-aside pattern starts by checking the cache for data before querying the database.

2fill in blank

medium

Complete the code to describe what happens if data is not found in the cache.

HLD

If the data is not in the cache, the system fetches it from the [1].

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Aclient

Bdatabase

Ccache

DAPI gateway

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to fetch data again from the cache.

Assuming data comes from the client or API gateway.

When cache misses occur, the system retrieves data from the database.

3fill in blank

hard

Fix the error in the description of updating the cache after fetching data.

HLD

After fetching data from the database, the system [1] the cache with the new data.

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Aupdates

Bdeletes

Cignores

Dinvalidates

Attempts:

3 left

💡 Hint

Common Mistakes

Thinking the cache should be invalidated or deleted after fetching data.

Ignoring the cache update step.

The cache-aside pattern updates the cache with fresh data after a database fetch to speed up future requests.

4fill in blank

hard

Fill both blanks to complete the cache-aside pattern steps for a write operation.

HLD

When data is updated, the system writes to the [1] first, then [2] the cache to keep it consistent.

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Adatabase

Breads

Cinvalidates

Dwrites

Attempts:

3 left

💡 Hint

Common Mistakes

Writing to the cache before the database.

Not invalidating the cache after a write.

In cache-aside, writes go to the database first, then the cache is invalidated to avoid stale data.

5fill in blank

hard

Fill all three blanks to complete the cache-aside pattern read flow with cache miss handling.

HLD

On a cache miss, the system fetches data from the [1], then [2] the cache, and finally [3] the data to the client.

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Adatabase

Bupdates

Creturns

Dinvalidates

Attempts:

3 left

💡 Hint

Common Mistakes

Invalidating the cache instead of updating it on a cache miss.

Returning data before updating the cache.

The system fetches from the database, updates the cache, and returns data to the client in the cache-aside pattern.