Using HBase from Scratch
HBase is a column-based distributed storage system that features high reliability, performance, and scalability. This section describes how to use HBase from scratch, including how to update the client on the Master node in the cluster, create a table using the client, insert data in the table, modify the table, read data from the table, delete table data, and delete the table.
Background
Suppose a user develops an application to manage users who use service A in an enterprise. The procedure of operating service A on the HBase client is as follows:
- Create the user_info table.
- Add users' educational backgrounds and titles to the table.
- Query user names and addresses by user ID.
- Query information by user name.
- Deregister users and delete user data from the user information table.
- Delete the user information table after service A ends.
ID |
Name |
Gender |
Age |
Address |
---|---|---|---|---|
12005000201 |
A |
Male |
19 |
City A |
12005000202 |
B |
Female |
23 |
City B |
12005000203 |
C |
Male |
26 |
City C |
12005000204 |
D |
Male |
18 |
City D |
12005000205 |
E |
Female |
21 |
City E |
12005000206 |
F |
Male |
32 |
City F |
12005000207 |
G |
Female |
29 |
City G |
12005000208 |
H |
Female |
30 |
City H |
12005000209 |
I |
Male |
26 |
City I |
12005000210 |
J |
Male |
25 |
City J |
Prerequisites
The client has been installed. For example, the client is installed in the /opt/client directory. The client directory in the following operations is only an example. Change it to the actual installation directory. Before using the client, download and update the client configuration file, and ensure that the active management node of Manager is available.
Procedure
For versions earlier than MRS 3.x, perform the following operations:
- Download the client configuration file.
- Log in to MRS Manager. For details, see Accessing Manager. Then, choose Services.
- Click Download Client.
Set Client Type to Only configuration files, Download To to Server, and click OK to generate the client configuration file. The generated file is saved in the /tmp/MRS-client directory on the active management node by default. You can customize the file path.
- Log in to the active management node of MRS Manager.
- On the Node tab page, view the Name parameter. The node that contains master1 in its name is the Master1 node. The node that contains master2 in its name is the Master2 node.
The active and standby management nodes of MRS Manager are installed on Master nodes by default. Because Master1 and Master2 are switched over in active and standby mode, Master1 is not always the active management node of MRS Manager. Run a command in Master1 to check whether Master1 is active management node of MRS Manager. For details about the command, see 2.d.
- Log in to the Master1 node using the password as user root.
- Run the following commands to switch to user omm:
sudo su - root
su - omm
- Run the following command to check the active management node of MRS Manager:
sh ${BIGDATA_HOME}/om-0.0.1/sbin/status-oms.sh
In the command output, the node whose HAActive is active is the active management node, and the node whose HAActive is standby is the standby management node. In the following example, mgtomsdat-sh-3-01-1 is the active management node, and mgtomsdat-sh-3-01-2 is the standby management node.
Ha mode double NodeName HostName HAVersion StartTime HAActive HAAllResOK HARunPhase 192-168-0-30 mgtomsdat-sh-3-01-1 V100R001C01 2021-11-18 23:43:02 active normal Actived 192-168-0-24 mgtomsdat-sh-3-01-2 V100R001C01 2021-11-21 07:14:02 standby normal Deactived
- Log in to the active management node, for example, 192-168-0-30 of MRS Manager as user root, and run the following command to switch to user omm:
sudo su - omm
- On the Node tab page, view the Name parameter. The node that contains master1 in its name is the Master1 node. The node that contains master2 in its name is the Master2 node.
- Run the following command to switch to the client installation directory, for example, /opt/client:
cd /opt/client
- Run the following command to update the client configuration for the active management node.
sh refreshConfig.sh /opt/client Full path of the client configuration file package
For example, run the following command:
sh refreshConfig.sh /opt/client /tmp/MRS-client/MRS_Services_Client.tar
If the following information is displayed, the configurations have been updated successfully.
ReFresh components client config is complete. Succeed to refresh components client config.
- Use the client on a Master node.
- On the active management node where the client is updated, for example, node 192-168-0-30, run the following command to go to the client directory:
cd /opt/client
- Run the following command to configure environment variables:
- If Kerberos authentication is enabled for the current cluster, run the following command to authenticate the current user. The current user must have the permission to create HBase tables. If Kerberos authentication is disabled for the current cluster, skip this step.
For example, kinit hbaseuser.
- Run the following HBase client command:
- On the active management node where the client is updated, for example, node 192-168-0-30, run the following command to go to the client directory:
- Run the following commands on the HBase client to implement service A.
- Create the user_info user information table according to Table 1 and add data to it.
create 'user_info',{NAME => 'i'}
For example, to add information about the user whose ID is 12005000201, run the following commands:
put 'user_info','12005000201','i:name','A'
put 'user_info','12005000201','i:gender','Male'
put 'user_info','12005000201','i:age','19'
put 'user_info','12005000201','i:address','City A'
- Add users' educational backgrounds and titles to the user_info table.
For example, to add educational background and title information about user 12005000201, run the following commands:
put 'user_info','12005000201','i:degree','master'
put 'user_info','12005000201','i:pose','manager'
- Query user names and addresses by user ID.
For example, to query the name and address of user 12005000201, run the following command:
scan'user_info',{STARTROW=>'12005000201',STOPROW=>'12005000201',COLUMNS=>['i:name','i:address']}
- Query information by user name.
For example, to query information about user A, run the following command:
scan'user_info',{FILTER=>"SingleColumnValueFilter('i','name',=,'binary:A')"}
- Delete user data from the user information table.
All user data needs to be deleted. For example, to delete data of user 12005000201, run the following command:
delete'user_info','12005000201','i'
- Delete the user information table.
drop 'user_info'
- Create the user_info user information table according to Table 1 and add data to it.
For MRS 3.x or later, perform the following operations:
- Use the client on the active management node.
- Log in to the node where the client is installed as the client installation user and run the following command to switch to the client directory:
- Run the following command to configure environment variables:
- If Kerberos authentication is enabled for the current cluster, run the following command to authenticate the current user. The current user must have the permission to create HBase tables.. If Kerberos authentication is disabled for the current cluster, skip this step.
For example, kinit hbaseuser.
- Run the following HBase client command:
- Run the following commands on the HBase client to implement service A.
- Create the user_info user information table according to Table 1 and add data to it.
create 'user_info',{NAME => 'i'}
For example, to add information about the user whose ID is 12005000201, run the following commands:
put 'user_info','12005000201','i:name','A'
put 'user_info','12005000201','i:gender','Male'
put 'user_info','12005000201','i:age','19'
put 'user_info','12005000201','i:address','City A'
- Add users' educational backgrounds and titles to the user_info table.
For example, to add educational background and title information about user 12005000201, run the following commands:
put 'user_info','12005000201','i:degree','master'
put 'user_info','12005000201','i:pose','manager'
- Query user names and addresses by user ID.
For example, to query the name and address of user 12005000201, run the following command:
scan'user_info',{STARTROW=>'12005000201',STOPROW=>'12005000201',COLUMNS=>['i:name','i:address']}
- Query information by user name.
For example, to query information about user A, run the following command:
scan'user_info',{FILTER=>"SingleColumnValueFilter('i','name',=,'binary:A')"}
- Delete user data from the user information table.
All user data needs to be deleted. For example, to delete data of user 12005000201, run the following command:
delete'user_info','12005000201','i'
- Delete the user information table.
drop 'user_info'
- Create the user_info user information table according to Table 1 and add data to it.
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