mongodb主从同步状态检查 mongodb主从同步速度

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mob64ca14116c53 2024-03-29 17:28:13

文章标签 mongodb主从同步状态检查 mongodb 数据库 2d 文章分类 MongoDB 数据库

主从复制是mongodb最常用的复制方式,这种方式很灵活.可用于备份,故障恢复,读扩展等。最基本的设置方式就是建立一个主节点和一个或多个从节点,每个从节点要知道主节点的地址。

在这里我们用一主一从实现mongodb的复制：

1.主机

mongodb-master  10.48.255.244   master

mongodb-slave   10.48.255.243   slave

2.把安装过程应用于mongodb这两个主机，配置文件稍加改动

在mongodb-master上，配置文件增加

1
master=true
2
oplogSize=2048 #类似于mysql的日志滚动，单位m

在mongodb-slave上，配置文件增加：

1
slave=true
2
source=10.48.100.1:27017   #指定主mongodb server
3
slavedelay=10               #延迟复制，单位为秒
4
autoresync=true             #当发现从服务器的数据不是最新时，向主服务器请求同步数据

3.测试主从可用性

在两主机上启动mongodb： mongod -f /usr/local/mongodb/conf/mongod.conf

1.看日志信息

主上日志：

# tail /var/log/mongodb/mongodb.log 
 Thu Aug 16 17:59:44 [initandlisten] connection accepted from 10.48.255.243:38034 #1
 Thu Aug 16 17:59:57 [conn1] end connection 10.48.255.243:38034
 Thu Aug 16 18:00:08 [initandlisten] connection accepted from 10.48.255.243:38035 #2
 Thu Aug 16 18:00:43 [clientcursormon] mem (MB) res:30 virt:8749 mapped:4302

从上日志

# tail /var/log/mongodb/mongodb.log 
 Thu Aug 16 18:00:28 [replslave] repl: from host:10.48.255.244:27017
 Thu Aug 16 18:00:28 [replslave] repl:   applied 1 operations
 Thu Aug 16 18:00:28 [replslave] repl:   syncedTo: Aug 16 18:00:17 502d3531:1
 Thu Aug 16 18:00:28 [replslave] waiting until: 1345140038 to continue
 Thu Aug 16 18:00:28 [replslave] repl: sleep 10 sec before next pass
 Thu Aug 16 18:00:38 [replslave] repl: from host:10.48.255.244:27017
 Thu Aug 16 18:00:38 [replslave] repl:   applied 1 operations
 Thu Aug 16 18:00:38 [replslave] repl:   syncedTo: Aug 16 18:00:27 502d353b:1
 Thu Aug 16 18:00:38 [replslave] waiting until: 1345140048 to continue
 Thu Aug 16 18:00:38 [replslave] repl: sleep 10 sec before next pass

由上述信息知道主从可以建立通信了

2.下面我们在主上创建数据库，并插入集合文档，看其是否同步

在主服务器上：

# mongo
 MongoDB shell version: 2.0.7
 connecting to: test
 > show dbs
 4.201171875GB
 > use xin
 switched to db xin
 > db.test.save({title:"just test"})
 > db.test.find()
 { "_id" : ObjectId("502d3643c5664ca66103a7cf"), "title" : "just test" }
 > show dbs
 4.201171875GB
 0.203125GB
 >

注：xin是数据库名，test是集合名，{title:"just test"}是文档

mongodb中使用use即可创建一个数据库当然也可以切换数据库，和mysql有很大区别吧！

让我们来看看日志：

主 server上的日志：

Thu Aug 16 18:04:51 [FileAllocator] creating directory /mongo/db/_tmp
 Thu Aug 16 18:04:51 [FileAllocator] done allocating datafile /mongo/db/xin.ns, size: 16MB,  took 0.001 secs
 Thu Aug 16 18:04:53 [FileAllocator] allocating new datafile /mongo/db/xin.0, filling with zeroes...
 Thu Aug 16 18:04:53 [FileAllocator] done allocating datafile /mongo/db/xin.0, size: 64MB,  took 0.034 secs
 Thu Aug 16 18:04:53 [FileAllocator] allocating new datafile /mongo/db/xin.1, filling with zeroes...
 Thu Aug 16 18:04:53 [FileAllocator] done allocating datafile /mongo/db/xin.1, size: 128MB,  took 0.04 secs
 Thu Aug 16 18:04:53 [conn3] build index xin.test { _id: 1 }
 Thu Aug 16 18:04:53 [conn3] build index done 0 records 0.012 secs
 Thu Aug 16 18:04:53 [conn3] insert xin.test 2892ms
 Thu Aug 16 18:05:07 [initandlisten] connection accepted from 10.48.255.243:60173 #4
 Thu Aug 16 18:05:08 [conn4] end connection 10.48.255.243:60173

从 server上的日志：

Thu Aug 16 18:05:04 [replslave] repl: from host:10.48.255.244:27017
 Thu Aug 16 18:05:04 [replslave] resync: dropping database xin
 Thu Aug 16 18:05:04 [replslave] removeJournalFiles
 Thu Aug 16 18:05:04 [replslave] resync: cloning database xin to get an initial copy
 Thu Aug 16 18:05:04 [FileAllocator] allocating new datafile /mongo/db/xin.ns, filling with zeroes...
 Thu Aug 16 18:05:04 [FileAllocator] creating directory /mongo/db/_tmp
 Thu Aug 16 18:05:04 [FileAllocator] done allocating datafile /mongo/db/xin.ns, size: 16MB,  took 0 secs
 Thu Aug 16 18:05:04 [FileAllocator] allocating new datafile /mongo/db/xin.0, filling with zeroes...
 Thu Aug 16 18:05:04 [FileAllocator] done allocating datafile /mongo/db/xin.0, size: 64MB,  took 0 secs
 Thu Aug 16 18:05:04 [FileAllocator] allocating new datafile /mongo/db/xin.1, filling with zeroes...
 Thu Aug 16 18:05:04 [FileAllocator] done allocating datafile /mongo/db/xin.1, size: 128MB,  took 0.001 secs
 Thu Aug 16 18:05:04 [replslave] build index xin.test { _id: 1 }
 Thu Aug 16 18:05:04 [replslave] build index done 1 records 0 secs
 Thu Aug 16 18:05:04 [replslave] resync: done with initial clone for db: xin
 Thu Aug 16 18:05:04 [replslave] repl:   applied 1 operations

由上述日志可以看出xin数据库已经同步到从 server上了。

3.我们进入从 server 的mongodb确认一下

# mongo
 MongoDB shell version: 2.0.7
 connecting to: test
 > show dbs
 0.203125GB
 0.203125GB
 >
 > use xin
 switched to db xin
 > db.test.find()
 { "_id" : ObjectId("502d3643c5664ca66103a7cf"), "title" : "just test" }

我们创建的数据库数据并不多，为什么会有0.2G呢，这是因为mongodb预分配数据库的空间，这使下次向数据库中插入数据更快。

4.在从server 上查看Collection(集合)状态

> db.printCollectionStats()
 system.indexes
 {
"ns" : "xin.system.indexes",
"count" : 1,
"size" : 64,
"avgObjSize" : 64,
"storageSize" : 4096,
"numExtents" : 1,
"nindexes" : 0,
"lastExtentSize" : 4096,
"paddingFactor" : 1,
"flags" : 0,
"totalIndexSize" : 0,
"indexSizes" : {

},
"ok" : 1
 }
 ---
 test
 {
"ns" : "xin.test",
"count" : 1,
"size" : 44,
"avgObjSize" : 44,
"storageSize" : 8192,
"numExtents" : 1,
"nindexes" : 1,
"lastExtentSize" : 8192,
"paddingFactor" : 1,
"flags" : 1,
"totalIndexSize" : 8176,
"indexSizes" : {
"_id_" : 8176
},
"ok" : 1
 }
 ---

在从server 上查看主从复制的状态

ok,mongodb的主从复制搞定了!

> db.printReplicationInfo()
 this is a slave, printing slave replication info.
 source:   10.48.255.244:27017
 > 
 > db.printSlaveReplicationInfo()
 source:   10.48.255.244:27017

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