Ensuring data consistency and integrity

[Miles_0]

What are the best practices for ensuring data consistency and integrity when using cloud storage for large-scale applications? Specifically, how do different platforms handle issues like eventual consistency, data replication across regions, and conflict resolution in distributed environments? Are there any recommended tools or strategies to optimize these processes for high availability and reliability?

[Dani]

Good question. We have multiple web servers that are load balanced, and only 2 database servers in a master/slave setup. I know there are ways to shard the database so you could essentially put different records of a table on different servers, but I personally have no experience with that. I am pretty sure you can shard by row or by column.

We also have a Memcached pool (for caching) where we specify the server we want to use by passing in a server key into all gets and sets. We make sure that all cached items that need to be fetched on a particular page are fetched at once, and always from a single server. That seems to work well for us.

[Miles_0]

Thanks for overwhelming response. How do you ensure efficient cache management with Memcached in such a distributed system, especially when fetching multiple items per page while minimizing cache misses?

[Dani]

We make heavy use of PHP's Memcached::getDelayedByKey which requests multiple items all from a specific server (hashed on the server key, which is the Topic ID #). That ensures that when you pull up a topic, we can retrieve all items for that topic in one request, all from one server.