Re: [Tarantool-patches] [PATCH 1/4] raft: fix crash on election_timeout reconfig

[Serge Petrenko via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

15.01.2022 03:48, Vladislav Shpilevoy пишет:
> It used to crash if done during election on a node voted for
> anybody, it is a candidate, it doesn't know a leader yet, but has
> a WAL write in progress.
>
> Thus it could only happen if the term was bumped by a message from
> a non-leader node and wasn't flushed to the disk yet.
>
> The patch makes the reconfig check if there is a WAL write in
> progress. Then don't do anything.
>
> Could also check for volatile vote instead of persistent, but it
> would create the same problem for the case when started writing
> vote for self and didn't finish yet. Reconfig would crash.
> ---
>   .../unreleased/election-timeout-cfg-crash.md  |  5 ++
>   src/lib/raft/raft.c                           |  3 +-
>   test/unit/raft.c                              | 75 ++++++++++++++++++-
>   test/unit/raft.result                         | 16 +++-
>   4 files changed, 96 insertions(+), 3 deletions(-)
>   create mode 100644 changelogs/unreleased/election-timeout-cfg-crash.md
>
>

Good catch! LGTM.

-- 
Serge Petrenko