The document provides instructions and examples for common commands used in the HBase shell to perform operations like listing tables, creating tables, describing tables, counting rows, putting and getting values, scanning tables, and more. It also provides tips for scripting with HBase, different ways to back up and restore HBase data, and using Hive to run SQL queries on HBase tables.

1. dwivedishashwat@gmail.com

2. LIST
List all tables in HBase
Syntax :
Htase :> list

3. CREATE
Create table;
Pass table name
Syntax :
Hbase :> creat ‘tablename’,’colFamily’

4. MORE EXAPLES
hbase> create 'tableToBeCreated', {NAME => 'colFammily1', VERSIONS =>
5}
hbase> create 'tableToBeCreated', {NAME => 'colFammily1'}, {NAME =>
'colFammily2'}, {NAME => 'f3'}
hbase> # The above in shorthand would be the following:
hbase> create 'tableToBeCreated', 'colFammily1', 'colFammily2', 'f3'
hbase> create 'tableToBeCreated', {NAME => 'colFammily1', VERSIONS =>
1, TTL => 2592000, BLOCKCACHE => true

5. DESCRIBE
Describe the named table:
e.g.
hbase> describe 'table1'

6. COUNT
Count the number of rows in a table.
This operation may take a LONG time (Run
'$HADOOP_HOME/bin/hadoop jar hbase.jar
rowcount' to run a counting mapreduce job).
Current count is shown every 1000 rows by default.
Count interval may be optionally specified.
Examples:
hbase> count 't1' hbase> count 't1', 100

7. DELETE
Put a delete cell value at specified table/row/column
and optionally timestamp coordinates.
Eg:
Delete ‘table’,’colfam:columnname’

8. DELETEALL
Delete all cells in a given row; pass a table name, row,
and optionally a column and timestamp
Delete ‘table’,’rowkey’

9. DISABLE
Disable the named table:
e.g.
"hbase> disable 't1'"

10. DROP
Drop the named table. Table must first be disabled.
Eg:
Drop ‘tablename’

11. ENABLE
Enable the named table
Eg:
Enable ‘tablename’

12. EXISTS
Does the named table exist?
e.g.
"hbase> exists 't1'"

13. GET
Get row or cell contents; pass table name, row,
hbase> get 't1', 'r1'
hbase> get 't1', 'r1', {COLUMN => 'c1'}
hbase> get 't1', 'r1', {COLUMN => ['c1', 'c2', 'c3']}
hbase> get 't1', 'r1', {COLUMN => 'c1', TIMESTAMP
=> ts1}
hbase> get 't1', 'r1', {COLUMN => 'c1', TIMESTAMP
=> ts1, VERSIONS => 4}

14. PUT
Put a cell 'value' at specified table/row/column and optionally
timestamp coordinates.
To put a cell value into table 't1' at row 'r1' under column 'c1'
do:
hbase> put 't1', 'r1', 'c1', 'value'

15. SCAN
Scan a tableTo scan all members of a column family, leave the
qualifier empty as in 'col_family:'.
hbase> scan 't1’

16. STATUS
Show cluster status.
Can be 'summary', 'simple', or 'detailed'.
The default is 'summary'.
Examples:
hbase> status
hbase> status 'simple'
hbase> status 'summary'
hbase> status 'detailed'

17. SHUTDOWN
Shut down the cluster.

18. TRUNCATE
Disables, drops and recreates the
specified table.

19. VERSION
Output this HBase version

20. ALTER
Alter column family schema; pass table name and a dictionary
specifying new column family schema. Dictionaries are
described below in the GENERAL NOTES section. Dictionary
must include name of column family to alter.
For example,
To change or add the 'f1' column family in table 't1' from defaults
to instead keep a maximum of 5 cell VERSIONS, do:
hbase> alter 't1', {NAME => 'f1', VERSIONS => 5}
To delete the 'f1' column family in table 't1', do:
hbase> alter 't1', {NAME => 'f1', METHOD => 'delete'}

21. EXIT
Type
hbase> exit
to leave the HBase Shell

22. SCRIPTING
You can pass scripts to the HBase Shell by doing the
following:
bin/hbase shell PATH_TO_SCRIPT

23. SOME HBASE TRICKS
echo "create 'user', 'info'" | hbase shell
Using this command you can create table called use
with column family name info without entering to the
hbase shell.
for i in '0'..'4' do
put "user", "user_#{i}", "info:email",
"user_#{i}@hakunamapdata.com"
End
This will create 4 users with user#1 to 4 and put email
address too

24. SCRIPT FOR HBASE
cat hbase_user_part_scan.txt scan 'user',
{STARTROW => 'user_1', STOPROW => 'user_3'}
exit
$ hbase shell hbase_user_part_scan.txt
This script will scan the user table and give output.

25. USING BASH SCRIPT
#!/bin/bash TABLE=$1 STARTROW=$2
STOPROW=$3 exec hbase shell <<EOF scan
"${TABLE}", {STARTROW => "${STARTROW}",
STOPROW => "${STOPROW}"} EOF
$ ./part_scan.sh user user_1 user_3

26. SEE WHEN A RECORD WAS ADDED
get 'user', 'user_1‘
Time.at(1344763701019/1000)
Will show you the human understable time like
Sun Aug 12 11:28:21 +0200 2012

27. SCHEMA DESIGN
We can take advantage of table schema and store all
information realated to a given user in one row (but
in two separate column families: info and friend).
Last but not least, the rowkey can be simply the
user’s unique username.It leads us to the following
table schema:
Just visit this link for understanding more on schema
designing :
http://www.slideshare.net/hmisty/20090713-hbase-
schema-design-case-studies

28. ADDING MORE DATA TO HBASE TABLES
$ hbase shell
hbase(main):001:0> create 'user', 'info', 'friend'
hbase(main):002:0> put 'user', 'username1', 'friend:username2',
'childhood'
hbase(main):003:0> put 'user', 'username1', 'friend:username3',
'childhood'
hbase(main):004:0> put 'user', 'username2', 'friend:username3',
'childhood'
hbase(main):005:0> put 'user', 'username2', 'friend:username4',
'childhood'
hbase(main):006:0> put 'user', 'username3', 'friend:username5',
'childhood'
hbase(main):007:0> put 'user', 'username1', 'friend:username5',
'childhood‘
Or you can write an script to create these value

29. SPECIFYING DIFFERENT CONFIGURATION FOR HBASE SHELL
HBase Shell is started by using the hbase shell
command. This command uses the HBase
configuration file (hbase-site.xml) for the client to
find the cluster to connect to. After connecting to the
cluster, it starts a prompt, waiting for commands. As
shown in the following code, you can also use the --
config option, which allows you to pass a different
configuration for HBase Shell to use:
hbase --config <configuration_directory> shell

30. SOME HELPFUL COMMANDS : EXERCISE
Get a specified row by using the get command:
Delete a specified cell by using the delete command:
Delete all the cells in a given row using the deleteall
command:
enable the balancer

31. ANSWERS
get 't1', 'row1'
delete 't1', 'row1', 'f1:c1‘
deleteall 't1', 'row1‘
balance_switch true

32. CHECKING THE CONSISTENCY OF AN HBASE CLUSTER
Bin/hbase hbck

33. YOU WANT TO QUERY HBASE USING SQL????
Use hive to query . For that you need to create a table in hive as
external table to hbase as follows:
create external table hbase_tablehbase
(key string, v01 string, v02 string, v03 string)
stored by 'org.apache.hadoop.hive.hbase.HBaseStorageHandler'
with serdeproperties ("hbase.columns.mapping" =
":key,n:v01,n:v02,n:v03")
tblproperties("hbase.table.name" = "tablehbase");
select * from hbase_hly_temp where v01='808C';
You can give this query in hive to get data from hbase  and you
have lot of other options with hive just visit :
http://karmasphere.com/hive-queries-on-table-data

34. BACKING UP AND RESTORING HBASE DATA
• Full shutdown backup using distcp
• Using CopyTable to copy data from one table to
another
• Exporting an HBase table to dump files on HDFS
• Restoring HBase data by importing dump files from
HDFS
• Backing up NameNode metadata
• Backing up region starting keys
• Cluster replication

35. Gmail dwivedishashwat@gmail.com
Twitter shashwat_2010
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Skype shriparv