为了设置副本集,我在 3 个单独的终端选项卡中运行:
$ sudo mongod --replSet rs0 --dbpath /data/mining --port 27017
$ sudo mongod --replSet rs0 --dbpath /data/mining2 --port 27018
$ sudo mongod --replSet rs0 --dbpath /data/mining3 --port 27019
然后,我在 Mongo shell 中配置了复制并验证它是否有效:
> var rsconf = {
_id: "rs0",
members: [
{
_id: 0,
host: 'localhost:27017'
},
{
_id: 1,
host: 'localhost:27018'
},
{
_id: 2,
host: 'localhost:27019'
}
]
};
> rs.initiate(rsconf);
{
"info": "Config now saved locally. Should come online in about a minute.",
"ok": 1
}
// Some time later...
> rs.status()
{
"set": "rs0",
"date": ISODate("2013-06-17T13:23:45-0400"),
"myState": 2,
"syncingTo": "localhost:27017",
"members": [
{
"_id": 0,
"name": "localhost:27017",
"health": 1,
"state": 1,
"stateStr": "PRIMARY",
"uptime": 4582,
"optime": {
"t": 1371489546,
"i": 1
},
"optimeDate": ISODate("2013-06-17T13:19:06-0400"),
"lastHeartbeat": ISODate("2013-06-17T13:23:44-0400"),
"lastHeartbeatRecv": ISODate("2013-06-17T13:23:44-0400"),
"pingMs": 0
},
{
"_id": 1,
"name": "localhost:27018",
"health": 1,
"state": 2,
"stateStr": "SECONDARY",
"uptime": 5034,
"optime": {
"t": 1371489546,
"i": 1
},
"optimeDate": ISODate("2013-06-17T13:19:06-0400"),
"self": true
},
{
"_id": 2,
"name": "localhost:27019",
"health": 1,
"state": 2,
"stateStr": "SECONDARY",
"uptime": 4582,
"optime": {
"t": 1371489546,
"i": 1
},
"optimeDate": ISODate("2013-06-17T13:19:06-0400"),
"lastHeartbeat": ISODate("2013-06-17T13:23:44-0400"),
"lastHeartbeatRecv": ISODate("2013-06-17T13:23:45-0400"),
"pingMs": 0,
"syncingTo": "localhost:27017"
}
],
"ok": 1
}
我的脚本在主节点上运行良好:
$ ./runScripts.sh -h localhost -p 27017
MongoDB shell version: 2.4.3
connecting to: localhost:27017/test
Successful completion
但是,针对任一二级:
$ ./runScripts.sh -h localhost -p 27018
MongoDB shell version: 2.4.3
connecting to: localhost:27017/test
Mon Jun 17 13:30:22.989 JavaScript execution failed: count failed:
{ "note" : "from execCommand", "ok" : 0, "errmsg" : "not master" }
at src/mongo/shell/query.js:L180
failed to load: /.../.../myAggregateScript.js
我已经在多个地方阅读过使用 rs.slaveOk()
或 db.getMongo().setSlaveOk()
,但这些都没有任何效果,无论是从外壳输入还是在我的脚本中调用。这些语句在调用时没有抛出错误,但它们也没有解决问题。
有谁知道为什么我不能将我的 replset 配置为允许查询辅助节点?
最佳答案
rs.slaveOk()
在 mongo shell 中运行将允许您从辅助节点读取。这是在 MongoDB 2.4.3 下使用 mongo shell 的演示:
$ mongo --port 27017
MongoDB shell version: 2.4.3
connecting to: 127.0.0.1:27017/test
replset:PRIMARY> db.foo.save({})
replset:PRIMARY> db.foo.find()
{ "_id" : ObjectId("51bf5dbd473d5e80fc095b17") }
replset:PRIMARY> exit
$ mongo --port 27018
MongoDB shell version: 2.4.3
connecting to: 127.0.0.1:27018/test
replset:SECONDARY> db.foo.find()
error: { "$err" : "not master and slaveOk=false", "code" : 13435 }
replset:SECONDARY> rs.slaveOk()
replset:SECONDARY> db.foo.find()
{ "_id" : ObjectId("51bf5dbd473d5e80fc095b17") }
replset:SECONDARY> db.foo.count()
1
关于MongoDB 副本集阻止对辅助的查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17153813/