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Redis 3.0.0 is out

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Re: Redis 3.0.0 is out

#21

Post by famousactress »

gsnedders wrote: post #18

(To note, I have limited experience with using Redis. My questions may be stupid.) As far as I can tell, most of the advantages of Redis come from the fact that it's all held in memory and so access is fast. Is networked access to other parts of the cluster quick enough that it is quicker than storing the data on one computer, partly on disk? When would one want to use a Redis cluster rather than something stored on-…

The performance section of the spec[1] does a pretty good job explaining how the implementation remains fast.

    In Redis Cluster nodes don't proxy commands to the right
    node in charge for a given key, but instead they redirect
    clients to the right nodes serving a given portion of the
    key space.

    Eventually clients obtain an up to date representation 
    of the cluster and which node serves which subset of 
    keys, so during normal operations clients directly 
    contact the right nodes in order to send a given command.

    Because of the use of asynchronous replication, nodes 
    does not wait for other nodes acknowledgment of writes 
    (if not explicitly requested using the WAIT command).
[1] http://redis.io/topics/cluster-spec#performance

Re: Redis 3.0.0 is out

#22

Post by andrewstuart2 »

xofer wrote: post #14
agonzalezro wrote: post #3

For lazy readers: CLUSTERING!

Maybe it works great from day one, maybe it will need a few more iterations, and possibly with 3.2 we'll improve support for many stuff, but my guess is that Redis 3.0.0 today, in some way, changes what Redis is.

Noooo, apologies for the downvote. That "up" button is tiny and apparently easy to miss.

Re: Redis 3.0.0 is out

#23

Post by meritt »

gsnedders wrote: post #18

(To note, I have limited experience with using Redis. My questions may be stupid.) As far as I can tell, most of the advantages of Redis come from the fact that it's all held in memory and so access is fast. Is networked access to other parts of the cluster quick enough that it is quicker than storing the data on one computer, partly on disk? When would one want to use a Redis cluster rather than something stored on-…

The primary advantage of Redis is native data types and access patterns beyond simple key-values: lists, sets, sorted sets, hash tables, pub/sub, hyperloglog, and scripting (lua) support.

Being memory-based was simply a feature but not necessarily something that set it apart: Memcached had that area pretty well locked down for being a blazing fast key-value store. And then Membase was basically memcached + persistence and clustering. Now Redis has clustering too!

Re: Redis 3.0.0 is out

#24

Post by mmahemoff »

gsnedders wrote: post #18

(To note, I have limited experience with using Redis. My questions may be stupid.) As far as I can tell, most of the advantages of Redis come from the fact that it's all held in memory and so access is fast. Is networked access to other parts of the cluster quick enough that it is quicker than storing the data on one computer, partly on disk? When would one want to use a Redis cluster rather than something stored on-…

As well as the optimisations mentioned by famousactress, note that it's common to run Redis (or other in-memory databases such as memcached) on a separate server anyway. So there's already some network overhead but it tends to be small enough if the content is small and everything's co-located.

Re: Redis 3.0.0 is out

#27

Post by antirez »

flowerpot wrote: post #25

Does the cluster feature deprecate redis-sentinel?

No... Sentinel will still be developed alongside with Redis Cluster. For single instance deployments where all you want is HA, Sentinel may be a more obvious way to get it compared to running Redis in cluster mode. In the long term, with plenty of early warnings, we may support the current Sentinel use case with Cluster and merge the two stuff.

Re: Redis 3.0.0 is out

#28

Post by antirez »

beat wrote: post #19
yankoff wrote: post #8

I just hope it's not an April's fool joke

Yeah, clustered Redis, announced today? Sounds like a joke to me!

Not a joke, the release was due in these days, so I picked 1 April since we have a tradition now to ship 1 April. Last year with HyperLogLog support, because of the futuristic name of the data structure, people had an hard time to believe it was a really thing and not a joke.

Re: Redis 3.0.0 is out

#29

Post by flowerpot »

antirez wrote: post #27
flowerpot wrote: post #25

Does the cluster feature deprecate redis-sentinel?

No... Sentinel will still be developed alongside with Redis Cluster. For single instance deployments where all you want is HA, Sentinel may be a more obvious way to get it compared to running Redis in cluster mode. In the long term, with plenty of early warnings, we may support the current Sentinel use case with Cluster and merge the two stuff.

Neat! Really looking forward to that!

Re: Redis 3.0.0 is out

#30

Post by antirez »

martin1985 wrote: post #7

What is the best alternative for redis?

Depends on the use case, but basically, there is a big set of problems you can solve with different technologies depending on your exact details, one will be better in one way, one will be better in some other way. The sensibility of the programmer is to pick the right one, in an effort to maximize the different aspects: data model fitness for the problem at hand, operational aspects, consistency guarantees, performances (number of nodes needed), scalability, simplicity (do I need support since it's a complex stuff?), and so forth.
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