Hi,
current codes are:
```
long electionWait =
ClusterConstant.getElectionLeastTimeOutMs()
+ Math.abs(random.nextLong() %
ClusterConstant.getElectionRandomTimeOutMs());
```
where the comment says: electionLeastTimeOutMs should be at least as
long as a heartbeat;
IMO, these two parameters are enough, and we do not need to add more
parameters.
But the default value can be changed:
1. electionLeastTimeOutMs can be heartbeat *2 or something others,
rather than 2 seconds by default.
2. by default, electionRandomTimeOutMs can be 50 ms or something like
heartbeat/10 ?
Best,
-----------------------------------
Xiangdong Huang
School of Software, Tsinghua University
黄向东
清华大学 软件学院
Eric Pai <ericpa...@hotmail.com> 于2021年8月23日周一 上午10:18写道：
>
> Hi, Xiangdong,
>
> So what your suggestions about the election waiting time? Add another
> configuration parameter called election_wait_time_ms, or left as a shorter
> hardcode constant?
>
> 发件人: Eric Pai <ericpa...@hotmail.com>
> 日期: 2021年8月21日 星期六 下午7:32
> 收件人: "dev@iotdb.apache.org" <dev@iotdb.apache.org>
> 主题: 回复: Conclusion about JIRA issue[IOTDB-1564]: Make leader failure
> detection and election faster
>
> Hi, all,
>
> Now the randomElectionWait time is hardcode as 3-5s, which is not suitable
> when the heartbeat_interval_ms and election_timeout_ms is too small.
>
> I decide to change it to [2* heartbeat_interval_ms, 2* heartbeat_interval_ms
> + 50ms).
>
> The 50ms is referred from the Raft paper with a low probability and fast
> election when split votes happens.
>
> But I haven’t found any detailed descriptions about the relationship between
> heartbeat_interval_ms and the least waiting time.
>
> Any good suggestions?
>
> 发件人: 白 渐
> 发送时间: 2021年8月18日 22:14
> 收件人: dev@iotdb.apache.org
> 主题: Conclusion about JIRA issue[IOTDB-1564]: Make leader failure detection
> and election faster
>
> Hi, all,
>
> @Xinyu Tan and me have made a conclusion about the refine of hearbeat and
> election related timeout parameters:
>
> JIRA link: https://issues.apache.org/jira/browse/IOTDB-1564
>
> Two parameters are added:
>
> heartbeat_interval_ms (t1): The time interval(ms) between two rounds of
> heartbeat broadcast of one raft group leader.
>
> election_timeout_ms (t2 and t3): The election timeout time of candidates and
> followers, or as the parameter of waiting for voting result.
>
> t1 t1
> Leader view: Send HB - - -> Send HB - - -> Send HB
> t2
> t3
> Follower view: Receive HB - - -> Receive HB - - - - -> HB expired / Start
> election - - - - -> Election Timeout
>
> I will do the following works sooner or later:
>
> 1. Coding.
>
> 2. Proper test cases.
>
> 3. Docs about new parameters.
>
> Thanks.
>
>
