当应用的压力小时，可以减少一些节点来减少硬件资源的成本；总之这是一个长期且持续的工作。

   下面将刚刚添加的两个新节点28013 和28014 从复制集中去除掉，只需执行rs.remove 指令就可以了，具体如下:

rs1:PRIMARY> rs.remove("localhost:28014"){ "ok" : 1 }rs1:PRIMARY> rs.remove("localhost:28013"){ "ok" : 1 }

    查看复制集状态，可以看到现在只有28010、28011、28012 这三个成员，原来的28013 和28014 都成功去除了

rs1:PRIMARY> rs.status(){"set" : "rs1","date" : ISODate("2012-05-31T14:08:29Z"),"myState" : 1,"members" : [{"_id" : 0,"name" : "localhost:28010","health" : 1,"state" : 1,"stateStr" : "PRIMARY","optime" : {"t" : 1338473273000,"i" : 1},"optimeDate" : ISODate("2012-05-31T14:07:53Z"),"self" : true},{"_id" : 1,"name" : "localhost:28011","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 34,"optime" : {"t" : 1338473273000,"i" : 1},"optimeDate" : ISODate("2012-05-31T14:07:53Z"),"lastHeartbeat" : ISODate("2012-05-31T14:08:29Z")},{"_id" : 2,"name" : "localhost:28012","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 34,"optime" : {"t" : 1338473273000,"i" : 1},"optimeDate" : ISODate("2012-05-31T14:07:53Z"),"lastHeartbeat" : ISODate("2012-05-31T14:08:29Z")}],"ok" : 1}rs1:PRIMARY>