ovs/xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync
监视 Bridge 和 Interface OVSDB 表的 external_ids 列以查找需要询问 XAPI 的更改的守护进程。其职责包括：
- Set the "bridge-id" key in the Bridge table.
- Set the "iface-id" key in the Interface table.
- Set the fail-mode on internal bridges.
