"MongoDB" How to create MongoDB's replica set

Replica sets extension on master-slave replication, adding automatic failover and automatic repair of member nodes. The following is a technical introduction to how to build MongoDB replica set (personally feel that building MongoDB itself is not much dry, how important is disaster planning )

1 Setting up a data storage directory for replication cluster nodes

Mkdir-p/OPT/MONGODATA/R1

Mkdir-p/OPT/MONGODATA/R2

Mkdir-p/OPT/MONGODATA/R3

2 perform the following commands in three Windows, respectively:

./mongod--dbpath/opt/mongodata/r1--port 27018--rest--replset MySet

./mongod--dbpath/opt/mongodata/r2--port 27019--rest--replset MySet

./mongod--dbpath/opt/mongodata/r3--port 27020--rest--replset MySet

3 Execute the following command in the fourth window:

[Email protected] bin]$ /mongo 127.0.0.1:27018 init.js

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27018/test

Init.js content is as follows:

[email protected] bin]$ cat Init.js

Rs.initiate ({

_id: "MySet",

Members: [

{_id:0, Host: "10.250.7.220:27018"},

{_id:1, Host: "10.250.7.220:27019"},

{_id:2, Host: "10.250.7.220:27020"}

]

})

Start 3 service nodes, from the log log can be seen, three nodes negotiate with each other, select a node with Port 27018 as primary, and two automatically as the secondary node.

Mon Oct 20:27:53 [conn2] Replset info Saving a newer config version to Local.system.replset

Mon Oct to 20:27:53 [conn2] replset saveconfiglocally Done

Mon Oct to 20:27:53 [conn2] replset replsetinitiate config now saved locally. Should come online in about a minute.

Mon Oct to 20:27:53 [conn2] command admin. $cmd command: {replsetinitiate: {_id: "MySet", Members: [{_id:0.0, Host: "1 0.250.7.220:27018 "}, {_id:1.0, Host:" 10.250.7.220:27019 "}, {_id:2.0, Host:" 10.250.7.220:27020 "}]}} ntoreturn:1 reslen:112 12095ms

Mon Oct to 20:27:53 [conn2] End Connection 127.0.0.1:15252

Mon Oct to 20:27:53 [Rsstart] Replset STARTUP2

Mon Oct 20:27:53 [rshealthpoll] replset info 10.250.7.220:27019 is down (or slow to respond): Still initializing

Mon Oct to 20:27:53 [Rshealthpoll] Replset member 10.250.7.220:27019 is now on state down

Mon Oct 20:27:53 [rshealthpoll] replset info 10.250.7.220:27020 is down (or slow to respond): Still initializing

Mon Oct to 20:27:53 [Rshealthpoll] Replset member 10.250.7.220:27020 is now on state down

Mon Oct to 20:27:53 [Rssync] Replset Secondary

Mon Oct to 20:27:55 [Initandlisten] connection accepted from 10.250.7.220:44134 #3

Mon Oct to 20:27:59 [Rshealthpoll] Replset info member 10.250.7.220:27019 is up

Mon Oct to 20:27:59 [Rshealthpoll] Replset member 10.250.7.220:27019 is now on state STARTUP2

Mon Oct to 20:27:59 [rsmgr] not electing self, 10.250.7.220:27019 would veto

Mon Oct to 20:28:01 [Initandlisten] connection accepted from 10.250.7.220:44137 #4

Mon Oct to 20:28:05 [rsmgr] Replset info electself 0

Mon Oct to 20:28:05 [Rsmgr] Replset PRIMARY

Mon Oct to 20:28:07 [Rshealthpoll] Replset member 10.250.7.220:27019 is now on state RECOVERING

Mon Oct to 20:28:10 [Initandlisten] connection accepted from 10.250.7.220:44141 #5

Mon Oct to 20:28:10 [Initandlisten] connection accepted from 10.250.7.220:44142 #6

Mon Oct to 20:28:11 [slavetracking] Build index local.slaves {_id:1}

Mon Oct to 20:28:11 [slavetracking] Build index done 0 records 0.001 secs

Mon Oct to 20:28:13 [Rshealthpoll] Replset info member 10.250.7.220:27020 is up

Mon Oct to 20:28:13 [Rshealthpoll] Replset member 10.250.7.220:27020 is now on state STARTUP2

Mon Oct to 20:28:14 [conn6] End Connection 10.250.7.220:44142

Mon Oct to 20:28:14 [conn5] End Connection 10.250.7.220:44141

Mon Oct to 20:28:15 [Initandlisten] connection accepted from 10.250.7.220:44144 #7

Mon Oct to 20:28:15 [Rshealthpoll] Replset member 10.250.7.220:27019 is now on state secondary

Mon Oct to 20:28:15 [Rshealthpoll] Replset member 10.250.7.220:27020 is now on state RECOVERING

Mon Oct to 20:28:28 [Initandlisten] connection accepted from 127.0.0.1:59232 #8

To enter the database from the client:

[Email protected] bin]$/mongo 127.0.0.1:27018

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27018/test

Primary> Rs.status ()--View replica set status command

{

"Set": "MySet",

"Date": Isodate ("2011-10-31t12:29:17z"),

"MyState": 1,

"Members": [

{

"_id": 0,

"Name": "10.250.7.220:27018",

"Health": 1,

"state": 1,

"Statestr": "PRIMARY",

"Optime": {

"T": 1320064073000,

"I": 1

},

"Optimedate": Isodate ("2011-10-31t12:27:53z"),

"Self": true

},

{

"_id": 1,

"Name": "10.250.7.220:27019",

"Health": 1,

"state": 2,

"Statestr": "Secondary",

"Uptime": 78,

"Optime": {

"T": 1320064073000,

"I": 1

},

"Optimedate": Isodate ("2011-10-31t12:27:53z"),

"Lastheartbeat": Isodate ("2011-10-31t12:29:16z"),

"Pingms": 0

},

{

"_id": 2,

"Name": "10.250.7.220:27020",

"Health": 1,

"state": 2,

"Statestr": "Secondary",

"Uptime": 64,

"Optime": {

"T": 1320064073000,

"I": 1

},

"Optimedate": Isodate ("2011-10-31t12:27:53z"),

"Lastheartbeat": Isodate ("2011-10-31t12:29:16z"),

"Pingms": 1

}

],

"OK": 1

}

Key data bits in status

State:1 indicates that the host is currently capable of reading and writing, 2: cannot read and write

Health:1 indicates that the host is currently normal, 0: exception

The following is a read test from the library, error: {"$err": "Not Master and Slaveok=false", "Code": 13435}

Primary> rs.conf ()--View commands for replica set configuration

{

"_id": "MySet",

"Version": 1,

"Members": [

{

"_id": 0,

"Host": "10.250.7.220:27018"

},

{

"_id": 1,

"Host": "10.250.7.220:27019"

},

{

"_id": 2,

"Host": "10.250.7.220:27020"

}

]

}

Primary> Db.ismaster ();--To see if the command is the main library, you can certainly see it from the prompt PRIMARY

{

"SetName": "MySet",

"IsMaster": True, # #是primary

"Secondary": false,

"Hosts": [

"10.250.7.220:27018",

"10.250.7.220:27020",

"10.250.7.220:27019"

],

"PRIMARY": "10.250.7.220:27018",

"Me": "10.250.7.220:27018",

"Maxbsonobjectsize": 16777216,

"OK": 1

}

Log in to the other two MongoDB services separately:

[Email protected] bin]$ /mongo 127.0.0.1:27019

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27019/test

Secondary>

Secondary>

Secondary> Db.ismaster ();

{

"SetName": "MySet",

"IsMaster": false,

"Secondary": true,

"Hosts": [

"10.250.7.220:27019",

"10.250.7.220:27020",

"10.250.7.220:27018"

],

"PRIMARY": "10.250.7.220:27018",

"Me": "10.250.7.220:27019",

"Maxbsonobjectsize": 16777216,

"OK": 1

}

Secondary>

[Email protected] bin]$ /mongo 127.0.0.1:27020

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27020/test

Secondary>

Secondary> Db.ismaster ();

{

"SetName": "MySet",

"IsMaster": false,

"Secondary": true,

"Hosts": [

"10.250.7.220:27020",

"10.250.7.220:27019",

"10.250.7.220:27018"

],

"PRIMARY": "10.250.7.220:27018",

"Me": "10.250.7.220:27020",

"Maxbsonobjectsize": 16777216,

"OK": 1

}

This is the building of success.

Write to the main library and view it from the library:

[Email protected] bin]$ /mongo 127.0.0.1:27020

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27020/test

primary> Use test

Switched to DB test

Primary>

Primary> Db.yql.insert ({val: "This was a message on 27020 PRIMARY!"});

Primary>

Main Library log:

Mon Oct to 21:03:46 [Fileallocator] allocating new datafile/opt/mongodata/r3/test.ns, filling with zeroes ...

Mon Oct to 21:03:46 [Fileallocator] Done allocating datafile/opt/mongodata/r3/test.ns, SIZE:16MB, took 0.256 secs

Mon Oct to 21:03:46 [Fileallocator] allocating new datafile/opt/mongodata/r3/test.0, filling with zeroes ...

Mon Oct to 21:03:48 [Clientcursormon] Mem (MB) res:35 virt:2726 mapped:1248

Mon Oct to 21:03:50 [Fileallocator] Done allocating datafile/opt/mongodata/r3/test.0, SIZE:64MB, took 4.488 secs

Mon Oct to 21:03:50 [conn6] Build index TEST.YQL {_id:1}

Mon Oct to 21:03:50 [conn6] Build index done 0 records 0 secs

Mon Oct to 21:03:50 [conn6] Insert TEST.YQL 4759ms

Mon Oct to 21:03:50 [Fileallocator] allocating new datafile/opt/mongodata/r3/test.1, filling with zeroes ...

Mon Oct to 21:03:51 [CONN8] getmore local.oplog.rs query: {ts: {$gte: New Date (5669632022159556609)}} cursorid:6257712 144272734285 nreturned:1 reslen:146 5031ms

Mon Oct to 21:03:51 [conn5] getmore local.oplog.rs query: {ts: {$gte: New Date (5669632022159556609)}} cursorid:4238780 80662643430 nreturned:1 reslen:146 5631ms

Mon Oct to 21:03:54 [Fileallocator] Done allocating datafile/opt/mongodata/r3/test.1, SIZE:128MB, took 3.818 secs

From the library log, you can see the process of applying logs from the library, copying the data files from the main library.

Mon Oct to 20:49:27 [Clientcursormon] Mem (MB) res:19 virt:2693 mapped:1232

Mon Oct to 20:54:27 [Clientcursormon] Mem (MB) res:19 virt:2693 mapped:1232

Mon Oct to 20:59:27 [Clientcursormon] Mem (MB) res:19 virt:2693 mapped:1232

Mon Oct to 21:03:51 [Fileallocator] allocating new datafile/opt/mongodata/r2/test.ns, filling with zeroes ...

Mon Oct to 21:03:54 [Fileallocator] Done allocating datafile/opt/mongodata/r2/test.ns, SIZE:16MB, took 3.396 secs

Mon Oct to 21:03:54 [Fileallocator] allocating new datafile/opt/mongodata/r2/test.0, filling with zeroes ...

Mon Oct to 21:04:00 [Fileallocator] Done allocating datafile/opt/mongodata/r2/test.0, SIZE:64MB, took 5.79 secs

Mon Oct to 21:04:00 [Rssync] Build index TEST.YQL {_id:1}

Mon Oct to 21:04:00 [Rssync] Build index done 0 records 0 secs

Mon Oct to 21:04:00 [Fileallocator] allocating new datafile/opt/mongodata/r2/test.1, filling with zeroes ...

Mon Oct to 21:04:03 [Fileallocator] Done allocating datafile/opt/mongodata/r2/test.1, SIZE:128MB, took 2.965 secs

Mon Oct to 21:04:37 [Clientcursormon] Mem (MB) res:17 virt:2853 mapped:1312

Mon Oct to 21:04:41 [conn6] End Connection 127.0.0.1:44672

As described earlier in Rs.status (), state:1 indicates that the host is currently writable, 2: Cannot read and write

{

"_id": 1,

"Name": "10.250.7.220:27019",

"Health": 1,

"state": 2,--from the state of the library to 2, at this time is not read and write.

"Statestr": "Secondary",

"Uptime": 78,

"Optime": {

"T": 1320064073000,

"I": 1

},

When reading from the library, an error will be made.

[Email protected] bin]$/mongo 127.0.0.1:27019

MongoDB Shell version:2.0.1

Connecting To:127.0.0.1:27019/test

secondary> Use test

Switched to DB test

Secondary> Db.yql.find ();

Error: {"$err": "Not Master and Slaveok=false", "Code": 13435}

This article is from the "Dream to Reality" blog, please be sure to keep this source http://lookingdream.blog.51cto.com/5177800/1795016

"MongoDB" How to create MongoDB's replica set