Lock shard splitting targets during the initial copy phase
During the initial copy phase target shards are opened outside the
couch_server. Previously, it was possible to manually (via remsh for instance)
open the same targets via the couch_server by using the `couch_db:open/2` API
for example. That could lead to corruption as there would be two writers for
the same DB file.
In order to prevent such a scenario, introduce a mechanism for the shard
splitter to lock the target shards such that any regular open call would fail
during the initial copy phase.
The locking mechanism is generic and would allow local locking of shards for
possibly other reasons in the future as well.
5 files changed
