Hi, I'm somewhat lost in regards to the results I can expect from running range queries in a (temporarily) 'inconsistent' cluster (e.g. if node has been down for some time and hasn't caught up yet).
Suppose I have 4 nodes in 2 DCs (cassandra 1.1.7): DCa: a1 and a2 DCb: b1 and b2 I'm using ByteOrdered partitioner and nodes are balanced (tokens are set properly to split data evenly in each DC, tokens in DCb are [DCa + 1]). I'm running with replication DCa:2, DCb:2 (each node contains full data). I'm using counters only and I'm putting heavy load (say 10k increments per second). The writes are directed to a1 and a2 only, b1 and b2 are for backup and possibly for running queries against (haven't decided yet). I monitor cluster via nodetool and see that data load is even on all nodes (as is expected). Now a2 goes down. I can immediately see that a1 data load grows very-very rapidly (because of hints for a2). After half an hour a2 comes back up. I know from experience that it'll take hours before all hints from a1 will be sent to a2. What is going to happen with range queries directed to a1 & a2 while a2 catches up? As far as I understand, there's no read-repair when doing range queries, so there's no usual assurance of "wrong once, correct next time around". - Does consistency level setting apply to range queries? - If I direct query to a1 (which is up-to-date), will it go to a2 for the slice that 'belongs' to a2? (even though a1 has full replica of data) - If I direct query to a2 (which is NOT up-to-date), is it smart enough to go to a1 for data? - In general, considering I have a cluster with 3 nodes up-to-date and one that is not -- is there a way to run a query that'll return up-to-date data (i.e. will not use data from a2)? Also, what if a2 has been down for longer than hints window (1 hour by default)? Is Cassandra smart enough to avoid using a2 for range queries while it is inconsistent? Thanks in advance, Sergey -- View this message in context: http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Range-Queries-consistency-in-an-inconsistent-cluster-tp7585400.html Sent from the cassandra-u...@incubator.apache.org mailing list archive at Nabble.com.
