maria-developers team mailing list archive

[Sachin Setiya <sachin.setiya@xxxxxxxxxxx>]

Hi Kristian!

On Tue, Jan 10, 2017 at 4:41 PM, Kristian Nielsen
<knielsen@xxxxxxxxxxxxxxx> wrote:
> Sachin Setiya <sachin.setiya@xxxxxxxxxxx> writes:
>
>> Can we do something like send total no of  Rows_log_events in a event
>> group to slave. We can write this info in Gtid_log_event. Reason for
>> doing this is that on slave we can show how much progress we have
>> made.
>
> My immediate impression is that this sounds like a bad idea.
>
> It increases the binlog size without adding any real information - after all
> the event count can be determined easily by just reading the events.
>
You mean counting the all events in event group without applying them.
> It also requires careful design and testing for impact on forwards- and
> backwards compatibility.
>
> And event count is not a very meaningful progress indicator. One event group
> could have 10 Rows_log_event each with a single row operation. While another
> could have a single Rows_log_event that contains a hundred row operations.
>
Okay, So it there a better way to show progress in slave ?
> And why only rows event? What about Query_log_events in a transaction in
> statement-based replication?
We can generalize this idea to  Query_log_events also.
>
>  - Kristian.
Regards
sachin