cassandra - Cassandra如何处理并发更新？

Question

Cassandra如何处理多个用户对同一 key 的并发更新？ Cassandra是否遵循ACID的“隔离”属性？

Answer 1

虽然不是真正的ACID兼容，但是Cassandra强制执行行级isolation:

For example, if one user was writing a row with two thousand columns, another user could potentially read that same row and see some of the columns, but not all of them if the write was still in progress.

Full row-level isolation is in place, which means that writes to a row are isolated to the client performing the write and are not visible to any other user until they are complete.

至于由不同协调器节点处理的竞争写操作，每个列值都包含一个写时间值，该值指示该写时间。这样可确保对列的最新写入占用了单元格。换句话说，“最后写胜”。