基于python的web应用（四）
7.3.6 开启认证#sed -i “s/#keyFile/keyFile/”/opt/mongodb/security/*.conf
重启mongod，mongios服务：
l Server1 ：
# pkill mongod
# pkill mongios
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard10001.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard20001.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard30001.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/config1.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/mongos1.conf
#/opt/mongodb/bin/mongos -f /opt/mongodb/security/mongos1.conf
l Server2：
# pkill mongod
# pkill mongios
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard10002.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard20002.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard30002.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/config2.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/mongos2.conf
#/opt/mongodb/bin/mongos -f /opt/mongodb/security/mongos2.conf
l Server3 ：
# pkill mongod
# pkill mongios
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard10003.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard20003.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/shard30003.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/config3.conf
#/opt/mongodb/bin/mongod -f /opt/mongodb/security/mongos3.conf
#/opt/mongodb/bin/mongos -f /opt/mongodb/security/mongos3.conf
7.3.7测试分片实例：
root@debian:~# /opt/mongodb/bin/mongo 10.15.62.202:30000/admin
MongoDB shell version: 2.4.6
connecting to: 10.15.62.202:30000/admin
> db.auth("clusterAdmin","pwd")
1
mongos> show collections
system.indexes
system.users
mongos> use test
switched to db test
mongos> show collections
#对test数据库新建用户：
mongos> db.addUser({user:"test",pwd:"123456",roles:["readWrite","dbAdmin"]})
{
"user" : "test",
"pwd" : "c8ef9e7ab00406e84cfa807ec082f59e",
"roles" : [
"readWrite",
"dbAdmin"
],
"_id" : ObjectId("5241e3ffdaf821e8d4c5b9e7")
}
mongos>
mongos> show collections
system.indexes
System.users
#查看users集合中的内容：
mongos> db.system.users.find()
{ "_id" : ObjectId("5241e3ffdaf821e8d4c5b9e7"), "user" : "test", "pwd" : "c8ef9e7ab00406e84cfa807ec082f59e", "roles" : ["readWrite","dbAdmin" ] }
mongos> db
test
mongos> use admin
switched to db admin
#对数据库分片，test代表要分片的数据库
mongos> db.runCommand({enablesharding:"test"})
{ "ok" : 1 }
# 对集合分片，在test数据库的users表上分片,同时指明shard key是id这一列
mongos> db.runCommand({shardcollection:"test.users",key:{_id:1}})
{ "collectionsharded" : "test.users", "ok" : 1 }
mongos> db
admin
mongos> use test
switched to db test
mongos> show collections
system.indexes
system.profile
system.users
Users
#循环向test.users表中插入30万条数据,然后使用命令db.users.stats()查看表的分片情况.
mongos> for(var i=1;i<300000;i++) db.users.insert({name:"user"+i,age:i,email:"yanxiaoming@qq.com"})
mongos> show collections
system.indexes
system.profile
system.users
Users
#查看结果集
mongos> db.users.find()
{ "_id" : ObjectId("5241e618daf821e8d4c707a5"), "name" : "user85438", "age" : 85438, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45a"), "name" : "user6771", "age" : 6771, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9e8"), "name" : "user1", "age" : 1, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707a6"), "name" : "user85439", "age" : 85439, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45b"), "name" : "user6772", "age" : 6772, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9e9"), "name" : "user2", "age" : 2, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707a7"), "name" : "user85440", "age" : 85440, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45c"), "name" : "user6773", "age" : 6773, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9ea"), "name" : "user3", "age" : 3, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707a8"), "name" : "user85441", "age" : 85441, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45d"), "name" : "user6774", "age" : 6774, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9eb"), "name" : "user4", "age" : 4, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707a9"), "name" : "user85442", "age" : 85442, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45e"), "name" : "user6775", "age" : 6775, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9ec"), "name" : "user5", "age" : 5, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707aa"), "name" : "user85443", "age" : 85443, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d45f"), "name" : "user6776", "age" : 6776, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e5ffdaf821e8d4c5b9ed"), "name" : "user6", "age" : 6, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e618daf821e8d4c707ab"), "name" : "user85444", "age" : 85444, "email" : "yanxiaoming@qq.com" }
{ "_id" : ObjectId("5241e600daf821e8d4c5d460"), "name" : "user6777", "age" : 6777, "email" : "yanxiaoming@qq.com" }
Type "it" for more
mongos> db.users.stats()
{
"sharded" : true,
"ns" : "test.users",
"count" : 299999,
"numExtents" : 20,
"size" : 26399928,
"storageSize" : 60162048,
"totalIndexSize" : 10808672,
"indexSizes" : {
"_id_" : 10808672
},
"avgObjSize" : 88.00005333351112,
"nindexes" : 1,
"nchunks" : 14,
"shards" : {
"shard1" : {
"ns" : "test.users",
"count" : 60185,
"size" : 5296288,
"avgObjSize" : 88.00013292348592,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 2984240,
"indexSizes" : {
"_id_" : 2984240
},
"ok" : 1
},
"shard2" : {
"ns" : "test.users",
"count" : 200481,
"size" : 17642328,
"avgObjSize" : 88,
"storageSize" : 37797888,
"numExtents" : 8,
"nindexes" : 1,
"lastExtentSize" : 15290368,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 6540800,
"indexSizes" : {
"_id_" : 6540800
},
"ok" : 1
},
"shard3" : {
"ns" : "test.users",
"count" : 39333,
"size" : 3461312,
"avgObjSize" : 88.00020339155417,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 1283632,
"indexSizes" : {
"_id_" : 1283632
},
"ok" : 1
}
},
"ok" : 1
}
mongos>
7.4增加移除sharding节点
7.4.1增加sharding节点：
1 查看当前分分片信息：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
可以看到：存在3个切片，每个切片中存在3个节点
2 删除运行中的节点：
这里操作切片为：shard1 中的节点：
shard1:PRIMARY> rs.remove("10.15.62.203:10001")
Fri Sep 27 09:20:30.768 DBClientCursor::init call() failed
Fri Sep 27 09:20:30.770 Error: error doing query: failed at src/mongo/shell/query.js:78
Fri Sep 27 09:20:30.772 trying reconnect to 127.0.0.1:10001
Fri Sep 27 09:20:30.775 reconnect 127.0.0.1:10001 ok
shard1:PRIMARY>
3 查看日志：
Fri Sep 27 09:20:35.784 SocketException handling request, closing client connection: 9001 socket exception server
Fri Sep 27 09:20:35.785 SocketException handling request, closing client connection: 9001 socket exception server
4 再次查看当前分片信息验证：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
发现节点 10.15.62.203：10001 已经被移除
5 关闭10.15.62.203：10001 上的mongod进程即可
7.4.2增加节点：
这里已刚才刚才删除的节点10.15.62.203：10001为例
1启动新增的节点的mongo进程
2将新增的节点加入到切片中：
当前切片的节点信息：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
3 增加节点操作：
shard1:PRIMARY> rs.add("10.15.62.203:10001")
{ "down" : [ "10.15.62.203:10001" ], "ok" : 1 }
shard1:PRIMARY>
4 查看后台日志：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
可以看到已经添加到切片中了
5查看切片状态
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
6查看所有切片信息：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
7.5增加移除切片rep-set：
目前40w条数据存储在shard1，shard2，shard3上，考虑到数据分散不均匀，移除rep-set需要就行数据转移，这里选择数据较少的shard3：
1 查看test.user集合中的数据状态：
mongos> db.users.stats();
{
"sharded" : true,
"ns" : "test.users",
"count" : 399998,
"numExtents" : 20,
"size" : 35141840,
"storageSize" : 60162048,
"totalIndexSize" : 14406112,
"indexSizes" : {
"_id_" : 14406112
},
"avgObjSize" : 87.85503927519638,
"nindexes" : 1,
"nchunks" : 17,
"shards" : {
"shard1" : {
"ns" : "test.users",
"count" : 73297,
"size" : 6450144,
"avgObjSize" : 88.00010914498547,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 3752784,
"indexSizes" : {
"_id_" : 3752784
},
"ok" : 1
},
"shard2" : {
"ns" : "test.users",
"count" : 274257,
"size" : 24076616,
"avgObjSize" : 87.78851952730469,
"storageSize" : 37797888,
"numExtents" : 8,
"nindexes" : 1,
"lastExtentSize" : 15290368,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 8944544,
"indexSizes" : {
"_id_" : 8944544
},
"ok" : 1
},
"shard3" : {
"ns" : "test.users",
"count" : 52444,
"size" : 4615080,
"avgObjSize" : 88.00015254366562,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 1708784,
"indexSizes" : {
"_id_" : 1708784
},
"ok" : 1
}
},
"ok" : 1
}
2 执行移除操作：
mongos> db.runCommand({"removeshard":"shard3"});
{
"msg" : "removeshard completed successfully",
"state" : "started",
"shard" : "shard3",
"ok" : 1
}
3 查看迁移状态：
我们可以反复执行上面语句，查看执行结果。
mongos> db.runCommand({"removeshard":"shard3"});
{
"msg" : "draining ongoing",
"state" : "ongoing",
"remaining" : {
"chunks" : NumberLong(5),
"dbs" : NumberLong(0)
},
"ok" : 1
}
从上面可以看到，正在迁移，还剩下5块没迁移完。
当remain为0之后，这一步就结束了。
mongos> db.runCommand({"removeshard":"shard3"});
{
"msg" : "draining ongoing",
"state" : "ongoing",
"remaining" : {
"chunks" : NumberLong(2),
"dbs" : NumberLong(0)
},
"ok" : 1
}
mongos> db.runCommand({"removeshard":"shard3"});
{
"msg" : "removeshard completed successfully",
"state" : "completed",
"shard" : "shard3",
"ok" : 1
}
4 查看所有的sharding：
http://blog.51cto.com/e/u/themes/default/images/spacer.gif
Shard3 已经不在了
5 查看数据是否被切换到另外2个sharding上：
mongos> db.users.stats()
{
"sharded" : true,
"ns" : "test.users",
"count" : 399998,
"numExtents" : 20,
"size" : 35141832,
"storageSize" : 60162048,
"totalIndexSize" : 15738800,
"indexSizes" : {
"_id_" : 15738800
},
"avgObjSize" : 87.85501927509638,
"nindexes" : 1,
"nchunks" : 17,
"shards" : {
"shard1" : {
"ns" : "test.users",
"count" : 99519,
"size" : 8757680,
"avgObjSize" : 88.00008038665983,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 5257168,
"indexSizes" : {
"_id_" : 5257168
},
"ok" : 1
},
"shard2" : {
"ns" : "test.users",
"count" : 300479,
"size" : 26384152,
"avgObjSize" : 87.806974863468,
"storageSize" : 37797888,
"numExtents" : 8,
"nindexes" : 1,
"lastExtentSize" : 15290368,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 10473456,
"indexSizes" : {
"_id_" : 10473456
},
"ok" : 1
},
"shard3" : {
"ns" : "test.users",
"count" : 0,
"size" : 0,
"storageSize" : 11182080,
"numExtents" : 6,
"nindexes" : 1,
"lastExtentSize" : 8388608,
"paddingFactor" : 1,
"systemFlags" : 1,
"userFlags" : 0,
"totalIndexSize" : 8176,
"indexSizes" : {
"_id_" : 8176
},
"ok" : 1
}
},
"ok" : 1
}
mongos>
6 关闭对应的mongod进程
7注意：
① 在操作之前确保三台服务器同步时间一致，刚开始操作的时候没注意到这个问题，造成在删除切片的时候一直卡着不动，后台日志显示：
caught exception while doing balance: error checking clock skew of cluster 10.15.62.202:20
000,10.15.62.203:20000,10.15.62.205:20000 :: caused by :: 13650 clock skew of the cluster 10.15.62.202:20000,10.15.62.203:200
00,10.15.62.205:20000 is too far out of bounds to allow distributed locking.
② 如果该sharding中存在非切片数据，需要先将非sharding数据移除：
db.runCommand( { movePrimary: "非切片数据", to: "sharding" })至于非切片数据在进行移除切片数据的时候会报错，看报错信息就可以知道了
③ 增加sharding同上面一致
7.6 Replica Set 节点切换和 failover
MongoDB的sharding属性增加了数据的安全性和可靠性，而rep-set增加的则是数据的可用性，水平扩展了数据库的性能，replica set 特性支持自动 failover，当主节点由于某种原因掉线时，replica set 的其它节点可通过竞选产生新的主节点，因为同一个切片中sharding节点之间存在的数据都是一样的，默认情况下主节点primary具有可读写属性，secondary没有读写权限，当primary断掉后会进行重新选举出primary接管该sharding，至于如何重新选举，如何控制选举时间可以作为mongo性能优化的一个在后续说明，后面的mongodb维护文档中做过这方面的测试，这里就不特别指出了。
7.7关于sharding的几点说明：
① 关于keyfile和auth参数的问题
keyfile包含了auth参数，而且优先级更高，只有你设定了keyfile,auth参数被忽略，也就是开启了用户认证
② 对于shard和config实例，没添加用户前可以本地无验证登录，一旦添加用户，认证即可生效，连当前的session都会失效，需要从新登录
对于mongos实例由于它的一切信息来自config实例，必须要通过用户认证
③ 注意：keyfile参数必须子所有实例中指定，而且必须是同一个key
④ admin数据库的问题
admin是一个特殊的数据库，它不在整个sharding中复制
shard实例中的admin数据库是本地的，当然在同一个replica set是一样的，它仅限于登录shard实例
config实例中的admin同时给config实例和mongos实例用于实例认证
在mongos中添加的用户会同步到所有的config实例中
在config中添加的用户不会同步到其它config实例中，因为它不知道其它实例的存在
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