CODEWITHSUNDEEP
redis
X10nD
X10nD

Reputation: 22040

To build a RSS Reader

If I want to build an RSS reader then inserting all feeds in a MySQL would be too heavy for the DB server, CPU intensive.

So would having a Redis or cassandra, MySQL server with Apache help in the reducing the load on mysql server?

Upvotes: 1

Views: 173

Answers (1)

Eli
Eli

Reputation: 39009

Short answer: Yes, but it will add complexity.

Long answer: If MySQL isn't fast enough for you (and I would first verify that this is, in fact, the case before adding the complexity of Redis), you could throw some of the more frequent update/insert load onto Redis. A few ways to do this (you don't have to do everything here, but each thing will help with your load):

  1. Have a Redis pub/sub channel for each user. Publish directly to it whenever something is added to a user's feed. Have the RSS client subscribe to this channel, so if a user has his or her RSS reader open, they should just be subscribed to their pub/sub channel for updates, and never read from MySQL.

  2. Batch insert into MySQL: If you have heavy write volume, don't endure the network traffic and locking/unlocking and query overhead of inserting into MySQL every time something new should be added to the feed. Instead, save all new items in a per-user cache. Then empty the cache and do a bulk write every n seconds. Set n as high as needed for your use case.

  3. Cache feeds per user: If your read volume is very high despite #1, cache in Redis the last n items per user for m seconds (set n and m as befits your use case). Best way to cache these is most likely as a string. Use a list, if for some reason you need more dynamic access. Users should then read from MySQL only if their cache is unavailable.

Upvotes: 2

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