MongoDB 主从复制小实验
操作环境描述：WIN8 64位操作系统，内装虚拟机为CentOS 5.5 32位系统。
操作描述：跟其他关系型数据库类似，在主库进行数据操作，将数据同步到从节点，从节点可以配置多个。在本次试验中，master节点为主节点，我们在master节点中的对数据的插入、修改、删除操作都会同步到slave1和slave2节点。
以下为实验步骤：
（1）建立数据目录，数据目录用来存放过程中的数据。
[root@h3 dbs]# pwd /var/lib/mongo/dbs [root@h3 dbs]# ls master slave1 slave2 [root@h3 dbs]#
（2）启动master节点：
启动master
[root@h3 dbs]# mongod --dbpath /var/lib/mongo/dbs/master --port 10000 --master --rest --nojournal
Fri Aug 2 14:10:25.498 [initandlisten] MongoDB starting : pid=19491 port=10000 dbpath=/var/lib/mongo/dbs/master master=1 32-bit host=h3
Fri Aug 2 14:10:25.498 [initandlisten]
Fri Aug 2 14:10:25.498 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Fri Aug 2 14:10:25.498 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Fri Aug 2 14:10:25.498 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Fri Aug 2 14:10:25.499 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Fri Aug 2 14:10:25.499 [initandlisten]
Fri Aug 2 14:10:25.500 [initandlisten] db version v2.4.5
Fri Aug 2 14:10:25.500 [initandlisten] git version: a2ddc68ba7c9cee17bfe69ed840383ec3506602b
Fri Aug 2 14:10:25.500 [initandlisten] build info: Linux bs-linux32.10gen.cc 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
Fri Aug 2 14:10:25.500 [initandlisten] allocator: system
Fri Aug 2 14:10:25.500 [initandlisten] options: { dbpath: "/var/lib/mongo/dbs/master", master: true, nojournal: true, port: 10000, rest: true }
Fri Aug 2 14:10:25.540 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/master/local.ns, filling with zeroes...
Fri Aug 2 14:10:25.542 [FileAllocator] creating directory /var/lib/mongo/dbs/master/_tmp
Fri Aug 2 14:10:26.094 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/master/local.ns, size: 16MB, took 0.545 secs
Fri Aug 2 14:10:26.094 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/master/local.0, filling with zeroes...
Fri Aug 2 14:10:26.763 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/master/local.0, size: 16MB, took 0.667 secs
Fri Aug 2 14:10:26.785 [initandlisten] command local.$cmd command: { create: "startup_log", size: 10485760, capped: true } ntoreturn:1 keyUpdates:0 reslen:37 12 45ms
Fri Aug 2 14:10:26.796 [initandlisten] ******
Fri Aug 2 14:10:26.796 [initandlisten] creating replication oplog of size: 50MB...
Fri Aug 2 14:10:26.799 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/master/local.1, filling with zeroes...
Fri Aug 2 14:10:30.116 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/master/local.1, size: 64MB, took 3.314 secs
Fri Aug 2 14:10:30.243 [initandlisten] ******
Fri Aug 2 14:10:30.245 [initandlisten] waiting for connections on port 10000
Fri Aug 2 14:10:30.247 [websvr] admin web console waiting for connections on port 11000
Fri Aug 2 14:16:52.604 [initandlisten] connection accepted from 127.0.0.1:33749 #1 (1 connection now open)
Fri Aug 2 14:16:53.885 [slaveTracking] build index local.slaves { _id: 1 }
Fri Aug 2 14:16:53.894 [slaveTracking] build index done. scanned 0 total records. 0.008 secs
（3）启动slave1节点：
[root@h3 ~]# mongod -dbpath /var/lib/mongo/dbs/slave1 --port 10001 --slave --rest --nojournal --source localhost:10000
Fri Aug 2 14:16:50.050 [initandlisten] MongoDB starting : pid=19513 port=10001 dbpath=/var/lib/mongo/dbs/slave1 slave=1 32-bit host=h3
Fri Aug 2 14:16:50.051 [initandlisten]
Fri Aug 2 14:16:50.052 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Fri Aug 2 14:16:50.053 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Fri Aug 2 14:16:50.053 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Fri Aug 2 14:16:50.054 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Fri Aug 2 14:16:50.055 [initandlisten]
Fri Aug 2 14:16:50.055 [initandlisten] db version v2.4.5
Fri Aug 2 14:16:50.056 [initandlisten] git version: a2ddc68ba7c9cee17bfe69ed840383ec3506602b
Fri Aug 2 14:16:50.056 [initandlisten] build info: Linux bs-linux32.10gen.cc 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
Fri Aug 2 14:16:50.057 [initandlisten] allocator: system
Fri Aug 2 14:16:50.058 [initandlisten] options: { dbpath: "/var/lib/mongo/dbs/slave1", nojournal: true, port: 10001, rest: true, slave: true, source: "localhost: 10000" }
Fri Aug 2 14:16:50.080 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/slave1/local.ns, filling with zeroes...
Fri Aug 2 14:16:50.081 [FileAllocator] creating directory /var/lib/mongo/dbs/slave1/_tmp
Fri Aug 2 14:16:50.520 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/slave1/local.ns, size: 16MB, took 0.412 secs
Fri Aug 2 14:16:50.521 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/slave1/local.0, filling with zeroes...
Fri Aug 2 14:16:51.512 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/slave1/local.0, size: 16MB, took 0.989 secs
Fri Aug 2 14:16:51.520 [initandlisten] command local.$cmd command: { create: "startup_log", size: 10485760, capped: true } ntoreturn:1 keyUpdates:0 reslen:37 14 41ms
Fri Aug 2 14:16:51.524 [websvr] admin web console waiting for connections on port 11001
Fri Aug 2 14:16:51.525 [initandlisten] waiting for connections on port 10001
Fri Aug 2 14:16:52.577 [replslave] build index local.sources { _id: 1 }
Fri Aug 2 14:16:52.583 [replslave] build index done. scanned 0 total records. 0.004 secs
Fri Aug 2 14:16:52.595 [replslave] repl: syncing from host:localhost:10000
Fri Aug 2 14:16:52.657 [replslave] build index local.me { _id: 1 }
Fri Aug 2 14:16:52.662 [replslave] build index done. scanned 0 total records. 0.004 secs
Fri Aug 2 14:19:24.330 [replslave] repl: checkpoint applied 15 operations
Fri Aug 2 14:19:24.330 [replslave] repl: syncedTo: Aug 2 14:19:14 51fb4f62:1
（4）启动slave2节点：
[root@h3 ~]# mongod -dbpath /var/lib/mongo/dbs/slave2 --port 10002 --slave --rest --nojournal --source localhost:10000
Fri Aug 2 14:22:07.693 [initandlisten] MongoDB starting : pid=19596 port=10002 dbpath=/var/lib/mongo/dbs/slave2 slave=1 32-bit host=h3
Fri Aug 2 14:22:07.694 [initandlisten]
Fri Aug 2 14:22:07.695 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Fri Aug 2 14:22:07.696 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Fri Aug 2 14:22:07.696 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Fri Aug 2 14:22:07.697 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Fri Aug 2 14:22:07.698 [initandlisten]
Fri Aug 2 14:22:07.698 [initandlisten] db version v2.4.5
Fri Aug 2 14:22:07.699 [initandlisten] git version: a2ddc68ba7c9cee17bfe69ed840383ec3506602b
Fri Aug 2 14:22:07.700 [initandlisten] build info: Linux bs-linux32.10gen.cc 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_49
Fri Aug 2 14:22:07.700 [initandlisten] allocator: system
Fri Aug 2 14:22:07.701 [initandlisten] options: { dbpath: "/var/lib/mongo/dbs/slave2", nojournal: true, port: 10002, rest: true, slave: true, source: "localhost:10000" }
Fri Aug 2 14:22:07.713 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/slave2/local.ns, filling with zeroes...
Fri Aug 2 14:22:07.714 [FileAllocator] creating directory /var/lib/mongo/dbs/slave2/_tmp
Fri Aug 2 14:22:07.997 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/slave2/local.ns, size: 16MB, took 0.278 secs
Fri Aug 2 14:22:07.999 [FileAllocator] allocating new datafile /var/lib/mongo/dbs/slave2/local.0, filling with zeroes...
Fri Aug 2 14:22:08.373 [FileAllocator] done allocating datafile /var/lib/mongo/dbs/slave2/local.0, size: 16MB, took 0.373 secs
Fri Aug 2 14:22:08.381 [initandlisten] command local.$cmd command: { create: "startup_log", size: 10485760, capped: true } ntoreturn:1 keyUpdates:0 reslen:37 668ms
Fri Aug 2 14:22:08.383 [initandlisten] waiting for connections on port 10002
Fri Aug 2 14:22:08.386 [websvr] admin web console waiting for connections on port 11002
Fri Aug 2 14:22:09.391 [replslave] build index local.sources { _id: 1 }
Fri Aug 2 14:22:09.397 [replslave] build index done. scanned 0 total records. 0.005 secs
Fri Aug 2 14:22:09.398 [replslave] repl: syncing from host:localhost:10000
Fri Aug 2 14:22:09.405 [replslave] build index local.me { _id: 1 }
Fri Aug 2 14:22:09.409 [replslave] build index done. scanned 0 total records. 0.003 secs
（5）链接master，插入一条数据：
[root@h3 ~]# mongo localhost:10000
MongoDB shell version: 2.4.5
connecting to: localhost:10000/test
Server has startup warnings:
Mon Aug 12 08:23:21.713 [initandlisten]
Mon Aug 12 08:23:21.713 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Mon Aug 12 08:23:21.713 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Mon Aug 12 08:23:21.714 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Mon Aug 12 08:23:21.714 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Mon Aug 12 08:23:21.714 [initandlisten]
> use test;
switched to db test
> db.test.find();
> db.test.insert({'host': '1000'});
> db.test.find();
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "host" : "1000" }
>
（6）连接slave1节点，查询结果：
[root@h3 ~]# mongo localhost:10001
MongoDB shell version: 2.4.5
connecting to: localhost:10001/test
Server has startup warnings:
Mon Aug 12 08:23:34.870 [initandlisten]
Mon Aug 12 08:23:34.872 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Mon Aug 12 08:23:34.872 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Mon Aug 12 08:23:34.872 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Mon Aug 12 08:23:34.872 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Mon Aug 12 08:23:34.872 [initandlisten]
> use test;
switched to db test
> db.test.find();
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "host" : "1000" }
>
（7）连接slave2节点，查询结果：
[root@h3 ~]# mongo localhost:10002
MongoDB shell version: 2.4.5
connecting to: localhost:10002/test
Server has startup warnings:
Mon Aug 12 08:23:38.074 [initandlisten]
Mon Aug 12 08:23:38.075 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary.
Mon Aug 12 08:23:38.076 [initandlisten] ** 32 bit builds are limited to less than 2GB of data (or less with --journal).
Mon Aug 12 08:23:38.077 [initandlisten] ** Note that journaling defaults to off for 32 bit and is currently off.
Mon Aug 12 08:23:38.078 [initandlisten] ** See http://dochub.mongodb.org/core/32bit
Mon Aug 12 08:23:38.078 [initandlisten]
> use test;
switched to db test
> db.test.find();
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "host" : "1000" }
>
（8）执行修改操作，结果如下：
> db.test.update({'host': '1000'}, {'server': 'master'}); // master节点修改数据
> db.test.find() //master节点查看数据
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "server" : "master" }
>
> db.test.find(); // slave1 节点查看数据
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "server" : "master" }
>
> db.test.find(); // slave2节点查看数据
{ "_id" : ObjectId("52082b99d30e16a12c0f4277"), "server" : "master" }
>
（9）执行删除操作，结果如下：
> db.test.remove(); //master节点删除数据 > db.test.find(); //master节点查看数据 > > db.test.find(); //slave1节点查看数据 > > db.test.find(); //slave2节点查看数据 >
（9）在slave节点上进行数据插入和修改：
> db.test.insert({"host": "10001"});
not master
> db.test.remove();
not master
>
备注：
（1）MongoDB通过以上方式配置的主从同步只能在master端对数据进行新增、修改、删除操作，在slave节点只能进行查看操作。
（2）启动服务参数解释：
--dbpath /var/lib/mongo/dbs/master 指定数据存放目录为 /var/lib/mongo/dbs/master
--port 10000 指定监听端口为10000
--master 说明开启的是master服务进程
--slave 说明开启的是slave服务进程
--source localhost:10000 指定数据源为的地址为 localhost：100000
（3）服务启动后，可以通过：http://localhost:11000 查看master相关信息；查看http://localhost:10001、http://localhost:10002查看slave节点的信息。