Shulou(Shulou.com)06/01 Report--

Three ways to build http://blog.csdn.net/luonanqin/article/details/8497860 Mongodb Cluster

NoSQL = Not Only SQL mongodb storage is document storage, not Key-Value storage.

Construction of three cluster modes of Mongodb: Replica Set / Sharding / Master-Slaver

Replica Set replica set clustering principle: (the simplest way to cluster)

Primary node, standby node, arbitration node. The active and standby nodes store data, while the arbitration node does not store data.

The client connects the primary node and the standby node at the same time, but does not connect the arbitration node.

By default, the master node provides all addition, deletion, query and modification services, while the standby node does not provide any services. However, the standby node can be set up to provide query services, so that the pressure on the primary node can be reduced. When the client makes a data query, the request is automatically transferred to the standby node. This setting is called Read Preference Modes, and the Java client provides a simple way to configure it without having to manipulate the database directly.

Arbitration node is a special node, it does not store data, the main role is to determine which standby node is promoted to the primary node after the primary node dies, so the client does not need to connect to this node. Although there is only one standby node here, a quorum node is still needed to upgrade the standby node level.

Test: one is to insert data into the primary node, which can be checked from the standby node to the previously inserted data (querying the standby node may encounter a problem, you can check it on the Internet yourself). The second is to stop the primary node, the standby node can become the primary node to provide services. The third is to restore the primary node, the standby node can also restore its standby role, rather than continue to play the primary role. Both two and three can see the changes in the cluster in real time through the rs.status () command.

Sharding sharding cluster:

Similar to Replica Set, a quorum node is required, but Sharding also needs to configure nodes and routing nodes. In terms of the three ways to build a cluster, this is the most complex.

Master-Slaver active / standby mode

This method is no longer recommended by the authorities, and the construction method is relatively simple.

People who have used it should know that mongodb eats memory. The solution can only be controlled by ulimit, but if it is not properly controlled, mongodb will die.

Installation of mongodb

Execute the script install_mongodb_20160510.sh to install the mongodb service. Please see redme for details.

Installation of mongodb cluster

Common command

Startup of mongodb

/ opt/server/mongodb/bin/mongod-f / opt/server/mongodb/mongodb.conf

/ opt/server/mongodb/bin/mongod-f / opt/server/mongodb/mongodb.conf-- fork # standalone environment / is related to the configuration file, please refer to the configuration file for details

Stop of mongodb

Kill-15 pid

Pkill mongod

Mongodb login method

/ opt/server/mongodb/bin/mongo 192.168.1.200:27017

View statu

Rs.status ()

Delete a node:

Rs.remove ("mongodb13.kk.net:27019") # can delete nodes

Add a node:

Rs.addArb ("mongodb13.kk.net:27019") # can add nodes, but the nodes so added are arbitration

How do you add a node to a mongodb replica set to make it a backup node?

Operate on the primary node

Use admin

Cfg= {_ id: "wlb", members: [{_ id:0,host:'192.168.11.215:27017',priority:2}, {_ id:1,host:'192.168.11.187:27017',priority:1}, {_ id:2,host:'192.168.11.25:27017',arbiterOnly:true}]}

Rs.reconfig (cfg); # make the configuration effective

Rs.status ()

View all databases

Show dbs

MongoDB creates a database

Use znx

Db

Show dbs # will find that the created database is not in the list, and you need to insert data in order to display it

If the standby node wants to view the database, it needs to execute the following command, otherwise it reports a 13435 error.

Rs.slaveOk (true)

Insert data

Db.znx.insert ({"name": "dengyong"})

Show dbs # will display the znx database, and the standby node will also show

View all data tables

Show collections

View all table records

Db.znx.find ()

Delete the pushlog table

> db.Pushlog.drop () # specific operation. Enter db.Pushlog.d and press the table key to see what commands there are.

True

If the standby node views the data, execute the following command first, otherwise an error will be reported.

Rs.slaveOk (true)

MongoDB deletes the database

Use znx

Db.dropDatabase () # execute delete command

Show dbs # znx database has been deleted

Reference link: http://blog.csdn.net/chen88358323/article/details/50206651

Mongodb create user

Use admin

Db.createUser ({user: "wjs", pwd: "wjs", roles: [{role: "userAdminAnyDatabase", db: "admin"}]}) # create a user

Show users # you need to use the database first to view the user

Built-in roles:

1. Database user roles: read, readWrite

two。 Database management roles: dbAdmin, dbOwner, userAdmin

3. Cluster management roles: clusterAdmin, clusterManager, clusterMonitor, hostManager

4. Backup and restore roles: backup, restore

5. All database roles: readAnyDatabase, readWriteAnyDatabase, userAdminAnyDatabase, dbAdminAnyDatabase

6. Superuser role: root

/ / there are also several roles that provide access to the system superuser indirectly or directly (dbOwner, userAdmin, userAdminAnyDatabase)

7. Internal role: _ _ system

Specific roles:

Read: allows the user to read the specified database

ReadWrite: allows users to read and write to a specified database

DbAdmin: allows users to perform administrative functions in a specified database, such as index creation, deletion, viewing statistics, or accessing system.profile

UserAdmin: allows users to write to the system.users collection. You can create, delete and manage users in a specified database.

ClusterAdmin: available only in the admin database, giving users administrative rights to all shard and replication set related functions.

ReadAnyDatabase: available only in admin databases, giving users read access to all databases

ReadWriteAnyDatabase: available only in admin databases, giving users read and write permissions to all databases

UserAdminAnyDatabase: available only in admin databases, giving users userAdmin permissions for all databases

DbAdminAnyDatabase: available only in admin databases, giving users dbAdmin permissions for all databases.

Root: available only in the admin database. Super account, super privilege

Db.system.users.find () # View users

Show users

Create a database znx

Use znx

Create a normal user wxc

Db.createUser ({user: "wxc", pwd: "wxc", roles: [{role: "readWrite", db: "znx"}]})

Release the memory occupied by MongoDB

Restart the service to free memory, or use MongoDB's built-in closeAllDatabases command to do so:

Mongo > use admin

Mongo > db.runCommand ({closeAllDatabases:1})

Monitor the memory usage of MongoDB

Db.serverStatus () mem

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.