Scaling Memcache @Facebook

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?????????? ??????????????????: To mitigate the "thundering herd" problem, a lease mechanism is used. When a cache miss occurs, a lease token is assigned to one server, preventing multiple servers from simultaneously querying the backend database.

???????????????? ???????? ??????????????????: This helps in better memory management by reducing fragmentation and optimizing memory allocation for different sizes of data.

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???????????????? ?????? ????????????????: These tools are used to ensure data consistency across different regions by broadcasting invalidations whenever the data is updated in the database.

?????????????????????? ?????? ????????????????????????: SQL statements modifying data include the required cache keys, ensuring that updates are propagated to all relevant caches.

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???????????????? ????????????????: Splitting servers into regional clusters reduces latency and improves reliability by keeping data closer to users and mitigating the effects of large-scale outages.

?????????????????? ?????????? ?????? ?????????????????? ???????? ??????????: Assigning different pools to different types of data based on access patterns and memory requirements prevents negative interactions and optimizes performance.

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???????????? ??????????????: These are used as fallback when primary memcached servers fail, preventing cascading failures that can overload the system.

?????????????????????? ???????? ????????????????: Read requests are distributed across multiple replicas to balance the load and improve performance.

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???????????????? ????????????????: Utilizing Least Recently Used (LRU) eviction policies within each slab class ensures efficient memory use by discarding the least used items first.

???????? ????????????????????????: The design incorporates mechanisms to handle server failures gracefully, ensuring high availability and reliability of the caching system.

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This research article is still in progress. Will write another article part 2...