Re: [Tarantool-patches] [PATCH v4 01/11] recovery: do not call recovery_stop_local inside recovery_delete

[Konstantin Osipov <kostja.osipov@gmail.com>]

Hello,

* Georgy Kirichenko <georgy@tarantool.org> [20/02/12 13:09]:

> Recovery stop local raises an exception in case of an recovery error
> so it is not safe to stop recovery inside recovery delete and guard
> inside local_recovery. So call recovery_stop_local manually.

I suggest you try/catch the exception in recovery_delete instead,
or add a flag to recovery_stop_local to nothrow, or move
diag_raise() out of recovery_stop_local() and make sure
recovery_stop_local() returns 0, -1

It would be nice to explain in the changeset comment what is the
exact event chain that leads to an exception from
recovery_stop_local() - and even better - to add a test.

> Part of #980
> ---
>  src/box/box.cc      | 4 +++-
>  src/box/recovery.cc | 2 +-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/box/box.cc b/src/box/box.cc
> index 1b2b27d61..68038df18 100644
> --- a/src/box/box.cc
> +++ b/src/box/box.cc
> @@ -2238,8 +2238,10 @@ local_recovery(const struct tt_uuid *instance_uuid,
>  		recovery_follow_local(recovery, &wal_stream.base, "hot_standby",
>  				      cfg_getd("wal_dir_rescan_delay"));
>  		while (true) {
> -			if (path_lock(cfg_gets("wal_dir"), &wal_dir_lock))
> +			if (path_lock(cfg_gets("wal_dir"), &wal_dir_lock)) {
> +				recovery_stop_local(recovery);
>  				diag_raise();
> +			}
>  			if (wal_dir_lock >= 0)
>  				break;
>  			fiber_sleep(0.1);
> diff --git a/src/box/recovery.cc b/src/box/recovery.cc
> index 64aa467b1..a1ac2d967 100644
> --- a/src/box/recovery.cc
> +++ b/src/box/recovery.cc
> @@ -216,7 +216,7 @@ gap_error:
>  void
>  recovery_delete(struct recovery *r)
>  {
> -	recovery_stop_local(r);
> +	assert(r->watcher == NULL);
>  
>  	trigger_destroy(&r->on_close_log);
>  	xdir_destroy(&r->wal_dir);
> -- 
> 2.25.0

-- 
Konstantin Osipov, Moscow, Russia