No, I haven’t “thought why people don’t use Cassandra as a cache”, that’s why I’m asking this here. I’m asking the community for their POV when it might make sense to front Cassandra with Hazelcast. This is even mentioned as a use case in the Hazelcast documentation (“As a front layer for a Cassandra back-end”), and I’m aware of at least one large private enterprise that does this.
From: Dorian Hoxha [mailto:dorian.ho...@gmail.com] Sent: Friday, October 07, 2016 3:48 AM To: user@cassandra.apache.org Subject: Re: Rationale for using Hazelcast in front of Cassandra? Primary-key select is pretty fast in rdbms too and they also have caches. By "close to" you mean in latency ? Have you thought why people don't use cassandra as a cache ? While it doesn't have LRU, it has TTL,replicatio,sharding. On Fri, Oct 7, 2016 at 12:00 AM, KARR, DAVID <dk0...@att.com<mailto:dk0...@att.com>> wrote: Clearly, with “traditional” RDBMSs, you tend to put a cache “close to” the client. However, I was under the impression that Cassandra nodes could be positioned “close to” their clients, and Cassandra has its own cache (I believe), so how effective would it be to put a cache in front of a cache? From: Dorian Hoxha [mailto:dorian.ho...@gmail.com<mailto:dorian.ho...@gmail.com>] Sent: Thursday, October 06, 2016 2:52 PM To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Re: Rationale for using Hazelcast in front of Cassandra? Maybe when you can have very hot keys that can give trouble to your 3(replication) cassandra nodes ? Example: why does facebook use memcache ? They certainly have things distributed on thousands of servers. On Thu, Oct 6, 2016 at 11:40 PM, KARR, DAVID <dk0...@att.com<mailto:dk0...@att.com>> wrote: I've seen use cases that briefly describe using Hazelcast as a "front-end" for Cassandra, perhaps as a cache. This seems counterintuitive to me. Can someone describe to me when this kind of architecture might make sense?
