What is the reason for running Cassandra on Ceph? I have both running in my environment but doing different things - Cassandra as transactional store and Ceph as block storage for storing files. ________________________________ From: Jan<mailto:cne...@yahoo.com> Sent: 2/1/2015 2:53 AM To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Re: Cassandra on Ceph
Colin; Ceph is a block based storage architecture based on RADOS. It comes with its own replication & rebalancing along with a map of the storage layer. Some more details & similarities: a)Ceph stores a client’s data as objects within storage pools. (think of C* partitions)b) Using the CRUSH algorithm, Ceph calculates which placement group should contain the object, (C* primary keys & vnode data distribution) c) and further calculates which Ceph OSD Daemon should store the placement group (C* node locality) d) The CRUSH algorithm enables the Ceph Storage Cluster to scale, rebalance, and recover dynamically (C* big table storage architecture). Summary: C* comes with everything that Ceph provides (with the exception of block storage). There is no value add that Ceph brings to the table that C* does not already provide. I seriously doubt if C* could even work out of the box with yet another level of replication & rebalancing. Hope this helpsJan/ C* Architect On Saturday, January 31, 2015 7:28 PM, Colin Taylor <colin.tay...@gmail.com> wrote: I may be forced to run Cassandra on top of Ceph. Does anyone have experience / tips with this. Or alternatively, strong reasons why this won't work. cheersColin