mongodb - 在 MongoDb 中使用副本集的三个节点和 2 个已关闭

Question

在一个 3 节点副本集中，为什么当 2 个关闭时，第三个成为 SECONDARY 而不是 PRIMARY？

我希望在数据中心内有 2 个 mongod，在外部有一个，所以如果数据中心出现故障，我希望第三个外部 mongod 成为主节点。

没有和仲裁者有可能吗？

Answer 1

好的，找到回复了:

http://tebros.com/2010/11/mongodb-arbiters-with-only-two-replicas/

What happend?! It turns out that when a mongod instance is isolated, it cannot vote for itself to be primary. This makes sense when you think about it. If a network link went down and separated your two replicas, you wouldn’t want them both to elect themselves as primary. So in my case, when rep1-1 noticed that it was isolated from the rest of the replica set, it made itself secondary and stopped accepting writes.