What is the cache aside update strategy?
The cache-aside update strategy, also called
It is responsible for separately updating the cache and the database to minimize the amount of outdated data maintain data integrity.
Cache-aside is widely used in architectures like:
Memcached
Architecture
The architecture of cache-aside strategy explains the maintenance of data with cache and database.
Process
Reading the data:
a. When a read request is received, the application first checks if the requested data is available in the cache.
b. If it is, the data is returned directly from the cache.
c. If not, it is a cache miss.
d. The application finally retrieves the data from the database, caches it, and then returns it to the requester.
Updating the database and cache:
When an update request is received to modify data, the application follows these steps:
a. Removing outdated data: The application removes the stale data from the cache to ensure future reads fetch the latest data.
b. Update database: Then, the application updates the data in the database.
c. Update cache (optional): After updating the database, the application might update the cache with the latest and modified data to improve subsequent read performance.
Benefits
Some advantages of cache-aside update strategy are:
The cache-aside update approach makes managing data consistency flexible and effective.
By dividing the duties of reading and updating data, it reduces the need for complicated cache coherence methods.
The risk of serving outdated or inconsistent data from the cache is reduced by this strategy.
Drawbacks
However, there are a few drawbacks of using this strategy.
The cache-aside update strategy must carefully consider cache invalidation and synchronization, to maintain data integrity.
Developers must use proper techniques to handle cache updates and preserve consistency between the cache and the database.
The strategy may result in increased network latency when updating data since cache and database are updated independently.
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