Previous I met a consistency problem, you can refer the link below for the whole story.
And after check the code, seems I found some clue of the problem. Maybe some one can check this.
For short, I have Cassandra cluster (1.0.3), The consistency level is read/write quorum, replication_factor is 3.
Here is event sequence:
seqID NodeA NodeB NodeC
1. New New New
2. Update Update Update
3. Delete Delete
When try to read from NodeB and NodeC, "Digest mismatch" exception triggered, so Cassandra try to resolve this version conflict.
But the result is value "Update".
Here is the suspect root cause, the version conflict resolved based on time stamp.
Node C local time is a bit earlier then node A.
"Update" requests sent from node C with time stamp 00:00:00.050, "Delete" sent from node A with time stamp 00:00:00.020, which is not same as the event sequence.
So the version conflict resolved incorrectly.
It is true?
If Yes, then it means, consistency level can secure the conflict been found, but to solve it correctly, dependence one time synchronization's accuracy, e.g. NTP ?