Hi Peter, thanks for the response! I appreciate your validation of our needs. Sorry it's taken me so long to get back, I've been knocked on my ass with a nasty cold since late last week.
On Sat, Oct 16, 2010 at 7:37 AM, Peter Schuller <[email protected] > wrote: > > 2. What we really want for small users is just a replicated data store > with > > some caching. Each of our application instances would have all the data > > available to it. If one application instance goes down, the other nodes > > should continue to function just fine. > > Sounds reasonable, but make sure your application logic is okay to > handle concurrent requests to multiple nodes for the same data. I.e., > that there is no problem associated with your application not having > the only authoritative view of the data in-memory. > > Yeah, understood, I think we're ok with that, we won't have a lot of writes of data, we're more read-centric which concerns me a bit hearing that Cassandra is more write-centric. But we do have a need to store large amounts of data, so I think Cassandra is right for us based on that. > > So, with number 2, I've run into a situation that I don't think is going > to > > work for me, but hopefully I'm just missing something. To test 2., I > > installed a 2 node cluster. On node A, I ran some code to populate one > of > > the nodes. On both A and B, I can get data. Now, I shutdown node A and > > request data from Node B, I get a timed out exception from hector. If I > > leave A running, but shutdown B, I get an IllegalStateException: > replication > > factor (2) exceeds number of endpoints (1). I have set my > > replication_factor to 2. > > Can I do what I want with Cassandra? I appreciate any advice! And I > > apologize in advance if I've missed something obvious, I have all of > about > > 1.5 days experience and I'm trying to learn fast ;-) > > Does both A and B agree about the ring state (i.e., they both know > about both nodes) prior to you shutting one of them down? > > Actually, I figured out the problem on Friday night (sort of). My problem was either a bug in Hector (which I think is more likely at this point) or a misunderstanding of Hector on my part. It seems Hector wasn't taking my ConsistencyLevelPolicy (or whatever it's called in Hector). I switched to Pelops and things were working much more as I thought they should. So it does appear that Cassandra will do what I need thus far. > -- > / Peter Schuller >
