If you do CL=ONE write + CL=ALL read, then it seems OK... You should better to stay in this thread until some of experts would answer your question.
2011/5/14 Ryan Hadley <r...@sgizmo.com>: > Thanks Maki, > > That makes sense with my symptoms... I was doing a CL=ONE for write and a > CL=ALL for read, expecting that to be sufficient. > > I will try both set to ALL and see if I get better consistency. > > -Ryan > > On May 14, 2011, at 4:41 AM, Maki Watanabe wrote: > >> It depends on what you really use which CL for your operations. >> Your RF is 2, so if you read/write with CL=ALL, your r/w will be >> always consistent. If your read is CL=ONE, you have chance to read old >> data anytime, decommission is not matter. CL=QUORUM on RF=2 is >> semantically identical with CL=ALL. >> >> maki >> >> 2011/5/13 Ryan Hadley <r...@sgizmo.com>: >>> Hi, >>> >>> I'm running Cassandra (0.7.4) on a 4 node ring. It was a 3 node ring, but >>> we ended up expanding it to 4... So then I followed the many suggestions to >>> rebalance the ring. I found a script that suggested I use: >>> >>> # ~/nodes_calc.py >>> How many nodes are in your cluster? 4 >>> node 0: 0 >>> node 1: 42535295865117307932921825928971026432 >>> node 2: 85070591730234615865843651857942052864 >>> node 3: 127605887595351923798765477786913079296 >>> >>> So I started to migrate each node to those tokens. >>> >>> I have my replication factor set to 2, so I guess I was expecting to be >>> able to continue to use this ring without issues. But it seems that the >>> node still accepts writes while it's decommissioning? I say this because >>> if I interrupt the decommission by stopping Cassandra and starting it >>> again, it appears to run through several commit logs. And as soon as it's >>> through with those commit logs, I no longer get consistency issues. >>> >>> The issue I'm seeing is that writes to this ring will succeed, but it's >>> possible for a subsequent read to return an older object. For several >>> minutes even. >>> >>> I'm not sure if I did something wrong... learning as I go here and this >>> list archive has been very useful. But, is there anyway I can rebalance >>> the node and get better consistency? >>> >>> Thanks, >>> Ryan > > -- w3m
