**Write-through**: data is written in cache & DB; I/O completion is confirmed only when data is written in both places
**Write-around**: data is written in DB only; I/O completion is confirmed when data is written in DB
**Write-back**: data is written in cache first; I/O completion is confirmed when data is written in cache; data is written to DB asynchronously (background job) and does not block the request from being processed
I saw a lot of tech blog on the internet about caching strategies. And most of it said that in write through strategy, data was save to cache layer first and save to data source after that. Can you explain why?
I think the diagram is just missing the pros and cons of each strategy.
**Write-through**: data is written in cache & DB; I/O completion is confirmed only when data is written in both places
**Write-around**: data is written in DB only; I/O completion is confirmed when data is written in DB
**Write-back**: data is written in cache first; I/O completion is confirmed when data is written in cache; data is written to DB asynchronously (background job) and does not block the request from being processed
What does "IO completion confirmed" mean?
Is the cache connecting to the DB or what interaction is implied?
It implies when your application gets an ACK for the write operation completion.
I saw a lot of tech blog on the internet about caching strategies. And most of it said that in write through strategy, data was save to cache layer first and save to data source after that. Can you explain why?
This is the data flow of write through pattern by design, what do you mean WHY?
How can you share to choose best case to apply strategies
When to use what? The best strategy depends on your use case:
Cache-Aside: Good for read-heavy workloads where data updates can be slightly delayed.
Read-through: Simpler setup when reads significantly outweigh writes.
Write-through: Ensures strong consistency between the cache and the database.
Write-back: Prioritizes fast writes, risks some inconsistency if the cache fails before data is flushed.
Write-around: Useful for data that's infrequently read or doesn't need immediate caching.
Thanks for this post! Can you also comment on Write-behind? Also, I agree with the prior commenter that this should talk a little about pros and cons.
What is the difference between Cache Aside and Write Around? I know You've answer below, but, I didn't get, Could you elaborate on that more?
What is the difference between write-around and cache-aside? They both seem very similar.
write strategy and read strategy