我们如何理解cassandra中复制因子的概念？
How can we understand the concept of replication factor in cassandra?
cassandra 中的复制因子是什么？它如何影响单个 DC 或多个 DC 节点？
Cassandra stores replicas on multiple nodes to ensure reliability and fault tolerance. The total number of replicas across the cluster is referred to as the replication factor. A replication factor of 1 means that there is only one copy of each row on one node. A replication factor of 2 means two copies of each row, where each copy is on a different node. All replicas are equally important; there is no primary or master replica
创建keyspace时需要在每个DC上指定复制因子
使用 SimpleStrategy 的单个 DC 示例：
CREATE KEYSPACE Excelsior WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 3 };
- 这里我们指定replication_factor3的意思，每一行会放在三个不同的节点上。
多 DC 示例：
CREATE KEYSPACE Excalibur WITH REPLICATION = {'class' : 'NetworkTopologyStrategy', 'dc1' : 3, 'dc2' : 2};
- 此示例为名为 dc1 的数据中心设置了三个副本，为名为 dc2 的数据中心设置了两个副本
cassandra 中的复制因子是什么？它如何影响单个 DC 或多个 DC 节点？
Cassandra stores replicas on multiple nodes to ensure reliability and fault tolerance. The total number of replicas across the cluster is referred to as the replication factor. A replication factor of 1 means that there is only one copy of each row on one node. A replication factor of 2 means two copies of each row, where each copy is on a different node. All replicas are equally important; there is no primary or master replica
创建keyspace时需要在每个DC上指定复制因子
使用 SimpleStrategy 的单个 DC 示例：
CREATE KEYSPACE Excelsior WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 3 };
- 这里我们指定replication_factor3的意思，每一行会放在三个不同的节点上。
多 DC 示例：
CREATE KEYSPACE Excalibur WITH REPLICATION = {'class' : 'NetworkTopologyStrategy', 'dc1' : 3, 'dc2' : 2};
- 此示例为名为 dc1 的数据中心设置了三个副本，为名为 dc2 的数据中心设置了两个副本