Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Update 4.storage-service.md #681

Merged
merged 1 commit into from
Jul 2, 2021
Merged

Update 4.storage-service.md #681

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion docs-2.0/1.introduction/3.nebula-graph-architecture/4.storage-service.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -198,7 +198,7 @@ pId = vid % numParts + 1;

读写流程：对于客户端的每个写入请求，Leader 会将该写入以 Raft-wal 的方式，将该条同步给其他 Follower，并只有在“超过半数”副本都成功收到 Raft-wal 后，才会返回客户端该写入成功。对于客户端的每个读取请求，都直接访问 Leader，而 Follower 并不参与读请求服务。

故障流程：如果系统只有一个副本时，其自身就是 Leader；如果其发生故障，系统将完全不可用。如果系统有 3 个副本，其中一个副本是 Leader，其他 2 个副本是 Follower；即使原 Leader 发生故障，剩下两个副本仍可投票出一个新的Leader（以及一个Follower），此时系统仍可使用；但是当这2个副本中任一者再次发生故障后，由于投票人数不足，系统将完全不可用。
故障流程：场景1：考虑一个配置为单副本（图空间）的集群；如果系统只有一个副本时，其自身就是 Leader；如果其发生故障，系统将完全不可用。场景2：考虑一个配置为3副本（图空间）的集群；如果系统有 3 个副本，其中一个副本是 Leader，其他 2 个副本是 Follower；即使原 Leader 发生故障，剩下两个副本仍可投票出一个新的Leader（以及一个Follower），此时系统仍可使用；但是当这2个副本中任一者再次发生故障后，由于投票人数不足，系统将完全不可用。

!!! Note

Expand Down