Staging SSTables can be incorrectly added or removed from the backlog tracker,
after an ALTER TABLE or TRUNCATE, because the add and removal don't take
into account if the SSTable requires view building, so a Staging SSTable can
be added to the tracker after a ALTER table, or removed after a TRUNCATE,
even though not added previously, potentially causing the backlog to
become negative.
Fixes#6798.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20200716180737.944269-1-raphaelsc@scylladb.com>
b67066cae2