# Cache Consistency & Coherence

## Cache Coherence

(TODO)

## Cache Consistency

(TODO)

## References

* Blogs
  * [Consistency between Redis Cache and SQL Database](https://yunpengn.github.io/blog/2019/05/04/consistent-redis-sql/)
  * [Read-Through, Write-Through, Write-Behind Caching and Refresh-Ahead](https://docs.oracle.com/cd/E13924_01/coh.340/e13819/readthrough.htm)
  * [Cache Coherence Problem and Approaches](https://medium.com/@TechExpertise/cache-coherence-problem-and-approaches-a18cdd48ee0e)
  * [High-Performance Caching with NGINX and NGINX Plus](https://www.nginx.com/blog/nginx-high-performance-caching/)
* Videos
  * Georgia Tech - HPCA
    * [Cache Coherence Problem](https://www.youtube.com/watch?v=TMJj015C93A)
    * [How to Get Coherence](https://www.youtube.com/watch?v=In8RZg345pM)
    * [Write Update Snooping Coherence](https://www.youtube.com/watch?v=rLmS02gsEAk)
    * [Write Invalidate Snooping Coherence](https://www.youtube.com/watch?v=uLikXssApZk)
    * [MSI Coherence](https://www.youtube.com/watch?v=gAUVAel-2Fg\&t=310s)
    * [Directory Example](https://www.youtube.com/watch?v=lZZYILcQ68Y)