Raft论文翻译(5.4.2)——安全性-提交之前term的日志entry

5.4.2 Committing entries from previous terms

提交之前term的日志entry

As described in Section 5.3, a leader knows that an entry from its current term is committed once that entry is stored on a majority of the servers. If a leader crashes before committing an entry, future leaders will attempt to finish replicating the entry. However, a leader cannot immediately conclude that an entry from a previous term is committed once it is stored on a majority of servers. Figure 8 illustrates a situation where an old log entry is stored on a majority of servers, yet can still be overwritten by a future leader.

如 5.3 所述， 一旦当前任期内的某个日志条目已经存储到过半的服务器节点上，leader 就知道该日志条目已经被提交了。???

如果 leader 在提交一个 entry 之前 crash 了，新的 leader 将尝试 完成这个 entry 的复制；

然而，