本文分两部分介绍mongodb3.2.1分片部署配置及故障模拟验证。


第一部分  安装配置

一、实验环境

两组副本集做分片

版本3.2.1

副本集1192.168.115.11:27017,192.168.115.12:27017,192.168.115.11:47017(arbiter)

副本集2192.168.115.11:37017,192.168.115.12:37017,192.168.115.12:47017(arbiter)

configserver192.168.115.11:10000,192.168.115.11:10001,192.168.115.12:10000

mongos192.168.115.11:20000

二、分片介绍

1.逻辑图

wKioL1guYNDxIkitAADF6af6JP4875.png

片(shard):每一个分片一个副本集

配置服务器(config server):存储集群的配置信息,3.2以上版本支持副本集模式部署

路由进程(mongos):路由所有请求,然后将结果聚合。它不保存存储数据或配置信息,配置信息从配置服务器上加载到内存中。

 

副本集方式部署confiserver


一、部署条件

1.集群中不能有仲裁节点

2.集群中不能有延迟节点

3.每个成员必须可以创建索引

二、configserver安装配置

1.修改配置文件(其他两个节点配置文件类似,主要修改监听端口,及数据路径,如果一台机器上运行多个实例,注意配置文件名称要不一样)

cat config.conf
fork = true
quiet = true
port = 10000
dbpath = /data/config
logpath = /usr/local/mongodb/logs/config.log
logappend = true
directoryperdb = true
configsvr = true
replSet = hnrconfig/192.168.115.11:10000,192.168.115.11:10001,192.168.115.12:10000

2.服务启动和停止

/usr/local/mongodb/bin/mongod -f /usr/local/mongodb/etc/config.conf

 /usr/local/mongodb/bin/mongod --shutdown --port 10000 --dbpath=/data/config

3.配置副本集

连接任意一个节点进行配置

> show dbs

2016-11-17T09:06:08.088+0800 E QUERY    [thread1] Error: listDatabases failed:{ "ok" : 0, "errmsg" : "not master and slaveOk=false", "code" : 13435 } :

_getErrorWithCode@src/mongo/shell/utils.js:23:13

Mongo.prototype.getDBs@src/mongo/shell/mongo.js:53:1

shellHelper.show@src/mongo/shell/utils.js:700:19

shellHelper@src/mongo/shell/utils.js:594:15

@(shellhelp2):1:1

出现以上错误,需要执行

> rs.slaveOk()

> use admin

> db.runCommand({"replSetInitiate" : { "_id" : "hnrconfig" ,"members" : [ { "_id" : 1, "host" : "192.168.115.11:10000"},{ "_id" : 2, "host" : "192.168.115.12:10000"},{"_id" : 3, "host" : "192.168.115.11:10001"}]}})

{ "ok" : 1 }

三、mongos配置

1.配置文件

cat mongos.conf
fork = true
quiet = true
port = 20000
logpath = /usr/local/mongodb/logs/mongos.log
logappend = true
configdb = 192.168.115.11:10000,192.168.115.11:10001,192.168.115.12:10000

2.启动mongos服务

/usr/local/mongodb/bin/mongos -f /usr/local/mongodb/etc/mongos.conf

四、往集群中添加分片

连接mongos

mongos> sh.addShard("hnrtest1/192.168.115.11:27017")

{ "shardAdded" : "hnrtest1", "ok" : 1 }

mongos>

mongos> sh.addShard("hnrtest2/192.168.115.12:37017")

{ "shardAdded" : "hnrtest2", "ok" : 1 }

mongos>

wKiom1guYOeTOEFTAAA7ouKs0BA836.png

五、开启分片

1.先对数据库启用分片功能

mongos> sh.enableSharding("shardtest")

{ "ok" : 1 }

mongos>

2.对集合开启分片(自动分片建)

mongos> sh.shardCollection("shardtest.student",{"cre_id":1})

{ "collectionsharded" : "shardtest.student", "ok" : 1 }

mongos>

wKioL1guYQ2CZEhGAABsevAcsCU706.png

3.修改默认chunk大小(默认为64M),自动分片测试效果不好,需要插入大量数据,将其修改为1M

mongos> use config

mongos> db.settings.save({ "_id" : "chunksize", "value" : NumberLong(1) })

修改后对student2集合进行分片

mongos> sh.shardCollection("shardtest.student2",{"cre_id":1})

插入5万条数据

wKioL1guYVqRfOslAACS19BqsXc380.png

直接在后端分片副本集上查询

hnrtest2:PRIMARY> db.student2.find().count()

27081

hnrtest2:PRIMARY>

 

hnrtest1:PRIMARY> db.student2.find().count()

22918

hnrtest1:PRIMARY>

 

4.采用哈希分片

修改chunk为默认值64M

mongos> db.settings.save({ "_id" : "chunksize", "value" : NumberLong(64) })

student3集合在cre_id字段使用哈希分片

mongos> sh.shardCollection("shardtest.student3",{"cre_id":"hashed"})

{ "collectionsharded" : "shardtest.student3", "ok" : 1 }

mongos> sh.status()

 shardtest.student3

                        shard key: { "cre_id" : "hashed" }

                        unique: false

                        balancing: true

                        chunks:

                                hnrtest1        2

                                hnrtest2        2

                        { "cre_id" : { "$minKey" : 1 } } -->> { "cre_id" : NumberLong("-4611686018427387902") } on : hnrtest1 Timestamp(2, 2)

                        { "cre_id" : NumberLong("-4611686018427387902") } -->> { "cre_id" : NumberLong(0) } on : hnrtest1 Timestamp(2, 3)

                        { "cre_id" : NumberLong(0) } -->> { "cre_id" : NumberLong("4611686018427387902") } on : hnrtest2 Timestamp(2, 4)

                        { "cre_id" : NumberLong("4611686018427387902") } -->> { "cre_id" : { "$maxKey" : 1 } } on : hnrtest2 Timestamp(2, 5)

 

student3插入1万条数据,在每个分片上查询

hnrtest1:PRIMARY> db.student3.find().count()

4952

hnrtest1:PRIMARY>

 

hnrtest2:PRIMARY> db.student3.find().count()

5047

hnrtest2:PRIMARY>

 

第二部分  故障模拟验证

一、模拟config服务副本集primary节点宕机

1.关闭服务

/usr/local/mongodb/bin/mongod --shutdown --port 10000 --dbpath=/data/config

2.副本集重新选举一个primary节点

wKiom1guYWrwcIoGAABOqWLYxyQ471.png

3.读取数据,所有数据均正常返回

mongos> use shardtest

switched to db shardtest

mongos>

mongos> db.student.find().count()

99999

mongos> db.student2.find().count()

49999

mongos> db.student3.find().count()

9999

mongos>

4.对新的集合进行分片,插入5千条数据

mongos> sh.shardCollection("shardtest.student4",{"cre_id":"hashed"})

{ "collectionsharded" : "shardtest.student4", "ok" : 1 }

mongos>

在每个分片上查询数据

hnrtest2:PRIMARY> db.student4.find().count()

2525

hnrtest2:PRIMARY>

 

hnrtest1:PRIMARY> db.student4.find().count()

2474

hnrtest1:PRIMARY>

 

二、config服务数据备份恢复

1.数据备份

/usr/local/mongodb/bin/mongodump -h 192.168.115.11:10001 -o configdata

2.关闭所有config服务节点

/usr/local/mongodb/bin/mongod --shutdown --port 10000 --dbpath=/data/config

/usr/local/mongodb/bin/mongod --shutdown --port 10001 --dbpath=/data/config1

3.数据读取操作

由于mongos是将config的配置信息全部加载到内存中运行,因此此时通过mongos查询数据一切正常,但是不能对新的集合进行分片操作

mongos> db.student.find().count()

99999

mongos> db.student2.find().count()

49999

mongos> db.student3.find().count()

9999

mongos> db.student4.find().count()

4999

mongos>

4.对集合进行分片操作,无法完成

mongos> sh.shardCollection("shardtest.student5",{"cre_id":"hashed"})

{

        "ok" : 0,

        "errmsg" : "None of the hosts for replica set hnrconfig could be contacted.",

        "code" : 71

}

mongos>

 

5.关闭mongos服务,删除config节点所有数据

6.重新启动三个config服务

7.重新初始化副本集

> rs.slaveOk()

> use admin

> db.runCommand({"replSetInitiate" : { "_id" : "hnrconfig" ,"members" : [ { "_id" : 1, "host" : "192.168.115.11:10000"},{ "_id" : 2, "host" : "192.168.115.12:10000"},{"_id" : 3, "host" : "192.168.115.11:10001"}]}})

8.启动mongos服务,此时没有任何数据

wKioL1guYYGDqKWLAABHLloFA-Y505.png

 

9.导入备份的config数据

/usr/local/mongodb/bin/mongorestore -h 192.168.115.11:10000 -d config configdata/config/

mongos查询,但是查询数据会出现超时,数据无法查询

wKiom1guYZnCbrW2AABVhxF6D5I225.png

 

10.mongos执行如下命令

mongos> sh.enableSharding("shardtest")

{ "ok" : 0, "errmsg" : "Operation timed out", "code" : 50 }

mongos日志

2016-11-17T14:46:21.197+0800 I SHARDING [Balancer] about to log metadata event into actionlog: { _id: "node1.hnr.com-2016-11-17T14:46:21.197+0800-582d523ded1c4b679a84877b", server: "node1.hnr.com", clientAddr: "", time: new Date(1479365181197), what: "balancer.round", ns: "", details: { executionTimeMillis: 30007, errorOccured: true, errmsg: "could not get updated shard list from config server due to ExceededTimeLimit Operation timed out" } }

官网上说是bug,恢复失败

https://jira.mongodb.org/browse/SERVER-22392