1.复制集状态查询:rs.status()
2.查看当前副本集oplog状态:rs.printReplicationInfo()
3.查看复制延迟:rs.printSlaveReplicationInfo()
4.查看服务状态详情:db.serverStatus()
5.查询副本集配置:rs.conf()
6.主副本查询:db.isMaster()