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Earlier quoted context omitted.
For simple cases, it is probably a total overkill to even consider it, but for something heavier, embedding the database gives you a chance to trivially migrate later to a separate database server.
Redis is not a database. It’s a key / value store.
it's not a relational database.
While I love Redis as a versatile tool for external data structures, it's still lacking in two areas IMHO: One, it would be cool to be able to embed it, similar to sqlite, directly into applications. Two, the HA story is so much more complicated than it should be. I totally acknowledge that concurrency and distributed computing is hard, but it should not require reading heaps of documentation and understanding two en…
Genuinely interested why we need HA in redis, just not read round robin from multiple non-HA instances? Redis (and memcache) are memory caches and should be treated like that, not like highly consistent distributed session store.
If you haven't come across Kvrocks yet, it may be worth a look: https://github.com/apache/kvrocks https://kvrocks.apache.org/ . It's a database with a Redis-compatible wire protocol, but the database is stored on disk. This means your working set is not limited by RAM and can be a few orders of magnitude larger! On modern SSDs this is still very fast. I think it improves the durability story as well. But the big win is the orders of magnitude larger database space.
As I've been improving my side project https://totalrealreturns.com/ recently I've ended up using both Redis and Kvrocks together. Redis is great for small global state that needs to be super fast. Kvrocks is great for larger bulk data storage (large precomputed datasets), but also supports a lot of the Redis data structures as well as Lua scripts.
There's also a separate blog post that goes into the details of why existing data structures Redis already supported, which could provide array-like behavior, weren't good enough: https://redis.io/blog/diving-deep-into-rediss-new-array-data...
Earlier quoted context omitted.
Genuinely interested why we need HA in redis, just not read round robin from multiple non-HA instances? Redis (and memcache) are memory caches and should be treated like that, not like highly consistent distributed session store.
Redis is used for plenty of things, not just memory caches. For example if you use it for session storage, you can't have your application read from a random instance that may or may not contain the session.
Earlier quoted context omitted.
What would be the point of embedding Redis into an application? What's the advantage of using Redis over using the builtin (or third party) data structures of the language the application is developed in? I'm asking as a non-webdev who never quite got what Redis actually does, but would love to learn.
Probably because Redis gives you a very well-defined/understood set of rich data structures with built-in behavior like TTL, atomic operations, eviction, and persistence. These things are otherwise usually scattered across native types, helper classes, or entirely separate libraries.
Earlier quoted context omitted.
For simple cases, it is probably a total overkill to even consider it, but for something heavier, embedding the database gives you a chance to trivially migrate later to a separate database server.
Redis is not a database. It’s a key / value store.
A key-value database, or key-value store, is a data storage paradigm designed for storing, retrieving, and managing associative arrays, a data structure more commonly known today as a dictionary.
While I love Redis as a versatile tool for external data structures, it's still lacking in two areas IMHO: One, it would be cool to be able to embed it, similar to sqlite, directly into applications. Two, the HA story is so much more complicated than it should be. I totally acknowledge that concurrency and distributed computing is hard, but it should not require reading heaps of documentation and understanding two en…
What would be the point of embedding Redis into an application? What's the advantage of using Redis over using the builtin (or third party) data structures of the language the application is developed in? I'm asking as a non-webdev who never quite got what Redis actually does, but would love to learn.
given his ds4 project, likely collaborated with DeepSeek for this release: https://github.com/antirez/ds4
Where did everyone end up on the Redis/Valkey split? Is there still a reason to use Redis after the license kerfuffle?
So we’ve stayed with Valkey.
Earlier quoted context omitted.
Redis is used for plenty of things, not just memory caches. For example if you use it for session storage, you can't have your application read from a random instance that may or may not contain the session.
This case is exactly what he talks about. To get HA just setup more than one redis cache - or rebuild the session if it was lost in the redis cache.
Now you could solve this specific case by sharding by prefix, or by querying all instances, but then you still do not have high availability: if the instance a specific session is on is down, these users cannot authenticate. At that point you’re better off with a single instance.