content_image/843006.jpg
group replicates from the donor, until it gets to the marker with the view identifier which matches the view marker it is already in. 

<img src='content_image/843006.jpg'>

As view identifiers are transmitted to all members in the group at the same logical time, the server joining the group knows at which view identifier it should stop replicating. This avoids complex GTID set calculations because the view identifier clearly marks which data belongs to each group view. 

While the server joining the group is replicating from the donor, it is also caching incoming transactions from the group. Eventually, it stops replicating from the donor and switches to applying those that are cached. 

