A company is migrating an on-premises application to Azure. The application uses a custom caching layer that needs to be replaced with an Azure caching solution. The new cache must support both read-through and write-through caching patterns to simplify application code and keep the cache synchronized with the backend database. Which Azure caching service provides native support for these caching patterns?
- AAzure Cache for Redis
- BAzure SQL Database In-Memory OLTP
- CNeither Azure Cache for Redis nor any other Azure caching service provides native support for read-through/write-through caching.
- DAzure Storage Blob
Show answer & explanationAnswer & explanation
Correct answer: C. Neither Azure Cache for Redis nor any other Azure caching service provides native support for read-through/write-through caching.
While Azure Cache for Redis is a powerful distributed cache, it does not natively provide read-through or write-through caching capabilities out-of-the-box. These patterns typically need to be implemented in the application code or a separate caching layer that interacts with Redis and the backend database. Therefore, none of the listed Azure services offer native support for these specific patterns directly within the caching service itself.
Why the other options are wrong
- A. Azure Cache for Redis is a distributed cache but requires custom application logic to implement read-through and write-through patterns.
- B. Azure SQL Database In-Memory OLTP is for improving SQL query performance, not a separate caching service that supports read-through/write-through.
- D. Azure Storage Blob is an object storage service, not a caching service with read-through/write-through capabilities.
Read-Through/Write-Through Caching
Caching patterns where the cache interacts directly with the backend data store to load (read-through) or persist (write-through) data on behalf of the application, simplifying application logic.
- Read-through: Cache fetches data from DB if not present.
- Write-through: Cache writes data to DB synchronously.
- Requires custom implementation in most cloud caching services.
Memory trick: For 'through' patterns, your code must be clever, Azure's cache won't do it, no, never.