[tarantool-patches] Re: [PATCH v2 4/4] replication: use wal memory buffer to fetch rows

[Konstantin Osipov]

* Georgy Kirichenko <georgy at tarantool.org> [19/09/18 12:39]:
> A relay tries to create a wal memory cursor and follow them to relay
> data to it's replica. If a relay failed to attach to a wal memory buffer
> or went out of the buffer then the relay recovers xlogs from files and
> the makes a new try to attach.

A major review comment for the previous version of the series was
that in case of in-memory replications, relays using in-memory
buffer shouldn't bother advancing gc state independently - gc
state should be advanced upon chunk rotation of xrow_buf.

This seems to be a pretty straightforward thing to do, all you
need to do is have a trigger which is fired when xrow_buf rotates 
chunks. It would also save on wal gc events quite a bit and will
allow using the old approach with on_close_log() to notify gc
when relay is operating from files, not memory.

What was the issue with implementing these suggestions?

-- 
Konstantin Osipov, Moscow, Russia