I saw "The problem happens only if more than one directories are configured. When only one directory is configured, the problem won't happen. In the JIRA, we will allow auto format in the single directory case." in [1].
So, if I'm sure only one directory is configured, I can always use StartupOption.RECOVER. If it's possible to have multiple directories configured, perhaps I should write a launcher to check the directories and determine which startup option should be used. Best, tison. [1] https://issues.apache.org/jira/browse/RATIS-1871 Tsz Wo Sze <[email protected]> 于2024年1月10日周三 09:50写道： > > In order to prevent data loss, new servers should be formatted explicitly. > Auto-format may cause data loss as described in > https://issues.apache.org/jira/browse/RATIS-1677 . > > Tsz-Wo > > On Tue, Jan 9, 2024 at 5:32 PM tison <[email protected]> wrote: >> >> Thank you! Now I can make things work with >> `.setOption(RaftStorage.StartupOption.RECOVER)` on >> `RaftServer.newBuilder()`. >> >> I noticed that [1] enables fallback to format if recovery fails. And >> it meets my intuition that we can always try to recover and initialize >> if it fails. Still, the initialization can fail with "Failed to >> FORMAT: One or more existing directories found". I wonder when it's >> desired to configure `.setOption(RaftStorage.StartupOption.FORMAT)` >> since [1] is there. >> >> Best, >> tison. >> >> [1] https://github.com/apache/ratis/pull/903 >> >> Tsz Wo Sze <[email protected]> 于2024年1月10日周三 08:57写道： >> > >> > > ... between the two starting-ups. >> > >> > It is related to RaftStorage.StartupOption -- the default is FORMAT so the >> > first time can successfully start up. However, it failed to start up the >> > second time since the directory was already formatted. We should use the >> > RECOVER option for the subsequent startups. This change was for >> > https://issues.apache.org/jira/browse/RATIS-1677 . >> > >> > Sorry for the inconvenience. >> > >> > Tsz-Wo >> > >> > >> > On Tue, Jan 9, 2024 at 4:40 PM tison <[email protected]> wrote: >> >> >> >> Hi, >> >> >> >> It's a bit unexpected that startup and shutdown a ratis server with an >> >> empty state machine (extends BaseStateMachine without any override) >> >> returns this error: >> >> >> >> > Failed to FORMAT: One or more existing directories found >> >> >> >> The data under the directory should be compatible between the two >> >> starting-ups. >> >> >> >> You can reproduce it with [1] running EtcdServer's main function twice. >> >> >> >> I don't know why I encountered this exception and if it's a bug or if >> >> I should modify the application logic. >> >> >> >> Best, >> >> tison. >> >> >> >> [1] https://github.com/tisonkun/ratis-etcd
