Re: [Tarantool-patches] [PATCH v3 07/12] box: introduce `box.ctl.demote`

[Vladislav Shpilevoy via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Thanks for the fixes!

See 3 comments below.

> diff --git a/src/box/iproto.cc b/src/box/iproto.cc
> index 3ed641eea..5cc69b77f 100644
> --- a/src/box/iproto.cc
> +++ b/src/box/iproto.cc
> @@ -557,6 +558,20 @@ struct iproto_connection
>      struct iproto_thread *iproto_thread;
>  };
> 
> +#ifdef NDEBUG
> +#define iproto_write_error(fd, e, schema_version, sync)                         \
> +    iproto_do_write_error(fd, e, schema_version, sync);
> +#else
> +#define iproto_write_error(fd, e, schema_version, sync) do {                    \
> +    int flags = fcntl(fd, F_GETFL, 0);                                      \
> +    if (flags >= 0)                                                         \
> +        fcntl(fd, F_SETFL, flags & (~O_NONBLOCK));                      \
> +    iproto_do_write_error(fd, e, schema_version, sync);                     \
> +    if (flags >= 0)                                                         \
> +        fcntl(fd, F_SETFL, flags);                                      \
> +} while (0);
> +#endif

1. Why didn't you do this right in iproto_write_error? Why do
you need to change iproto.cc code at all?

> diff --git a/src/box/relay.cc b/src/box/relay.cc
> index 805b5e7ff..2947468ba 100644
> --- a/src/box/relay.cc
> +++ b/src/box/relay.cc
> @@ -444,20 +444,20 @@ relay_initial_join(int fd, uint64_t sync, struct vclock *vclock,
>       */
>      if (replica_version_id > 0) {
>          /* Mark the beginning of the metadata stream. */
> -        row.type = IPROTO_JOIN_META;
> -        coio_write_xrow(&relay->io, &row);
> +        xrow_encode_type(&row, IPROTO_JOIN_META);
> +        xstream_write(&relay->stream, &row);

2. Why do you use xtream_write? And why coio_write_xrow just a few lines
above works just fine then?

>          xrow_encode_raft(&row, &fiber()->gc, &raft_req);
> -        coio_write_xrow(&relay->io, &row);
> +        xstream_write(&relay->stream, &row);
> 
>          char body[XROW_SYNCHRO_BODY_LEN_MAX];
>          xrow_encode_synchro(&row, body, &req);
>          row.replica_id = req.replica_id;
> -        coio_write_xrow(&relay->io, &row);
> +        xstream_write(&relay->stream, &row);
> 
>          /* Mark the end of the metadata stream. */
> -        row.type = IPROTO_JOIN_SNAPSHOT;
> -        coio_write_xrow(&relay->io, &row);
> +        xrow_encode_type(&row, IPROTO_JOIN_SNAPSHOT);
> +        xstream_write(&relay->stream, &row);
>      }
> diff --git a/src/box/raft.c b/src/box/raft.c
> index f8d13aa32..bc69f7f1b 100644
> --- a/src/box/raft.c
> +++ b/src/box/raft.c
> @@ -83,6 +83,24 @@ box_raft_request_to_msg(const struct raft_request *req, struct raft_msg *msg)
>      };
>  }
> 
> +static void
> +box_raft_update_synchro_queue(struct raft *raft)
> +{
> +    assert(raft == box_raft());
> +    if (raft->state != RAFT_STATE_LEADER)
> +        return;
> +    int rc = 0;
> +    uint32_t errcode = 0;
> +    do {
> +        rc = box_promote_qsync();
> +        if (rc != 0) {
> +            struct error *err = diag_last_error(diag_get());
> +            errcode = box_error_code(err);
> +            diag_log();
> +        }

3. Could it stop being a leader during the retries? Would it
make sense to continue them then?

> +    } while (rc != 0 && errcode == ER_QUORUM_WAIT && !fiber_is_cancelled());
> +}