Re: [Tarantool-patches] [PATCH v2 0/4] Boot with anon

[Kirill Yukhin <kyukhin@tarantool.org>]

Hello,

On 15 сен 01:11, Vladislav Shpilevoy wrote:
> The patch attempts to address with problem of anonymous replicas being
> registered in _cluster, if they are present during bootstrap.
> 
> The bug was found during working on another issue related to Raft. The problem
> is that Raft won't work properly during bootstrap if non-joined replicas are
> registered in _cluster.
> 
> When their auto-registration by applier was removed, the anon bug was found.
> 
> The auto-registration removal is trivial, but it breaks the cluster bootstrap in
> another way creating false-positive XlogGap errors. See the second commit with
> an explanation. To solve the issue quite a radical solution is applied - gap
> errors are not considered critical anymore, and can be retried. I am not sure
> that is the best option, but couldn't come up with anything better after a long
> struggle with that.
> 
> This is a bug, so whatever we will come up with after all, it should be pushed
> to the older versions too.
> 
> Branch: http://github.com/tarantool/tarantool/tree/gerold103/gh-5287-anon-false-register
> Issue: https://github.com/tarantool/tarantool/issues/5287
> 
> Changes in v2:
> - Anon status is stored as a flag again. In v1 it was stored as enum, but an
>   alternative solution was proposed, where the enum is not needed.
> - Ballot now has a new field is_anon. It helps to avoid the enum, and set
>   replica->anon flag to a correct value right when it becomes connected. Through
>   relay or applier, either.
> 
> @ChangeLog
> * Anonymous replica could be registered and could prevent WAL files removal (gh-5287).
> * XlogGapError is not a critical error anymore. It means, box.info.replication will show upstream status as 'loading' if the error was found. The upstream will be restarted until the error is resolved automatically with a help of another instance, or until the replica is removed from box.cfg.replication (gh-5287).

I've checked your patchset into 2.5 and master.

--
Regards, Kirill Yukhin