[Tarantool-patches] [PATCH v14 1/6] qsync: track confirmed lsn number on reads

[Vladislav Shpilevoy]

Thanks for the patch!

On 10.09.2021 17:29, Cyrill Gorcunov via Tarantool-patches wrote:
> We will use this lsn for requests validation
> in next patches for sake of split-brain detection.

I don't understand. How exactly will it help?

> Part-of #6036
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>
> ---
>  src/box/txn_limbo.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/src/box/txn_limbo.c b/src/box/txn_limbo.c
> index 70447caaf..cca2ce493 100644
> --- a/src/box/txn_limbo.c
> +++ b/src/box/txn_limbo.c
> @@ -437,6 +437,13 @@ txn_limbo_read_confirm(struct txn_limbo *limbo, int64_t lsn)
>  		assert(e->txn->signature >= 0);
>  		txn_complete_success(e->txn);
>  	}
> +
> +	/*
> +	 * We use confirmed lsn number to verify requests and
> +	 * reject ones coming from split-brain cluster configurations,
> +	 * so update it even if there were no entries to process.
> +	 */
> +	limbo->confirmed_lsn = lsn;