HBase - Just The BasicsCopyright © 2015 Smoking Hand LLC. All rights Reserved 1 / 21

NoSQL Datastore built on top of the HDFS filesystem
HBase is a column family oriented database
Based on the Google BigTable paper
Uses HDFS for storage
Data can be retrieved quickly or batch processed with
MapReduce
What Is Apache HBase?
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Need Big Data TB/PB
High throughput
Variable columns
Need random reads and writes
HBase Use Cases
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HBase Architecture
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HBase Daemons
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NoSQL Table Architecture
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Column Families
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NoSQL Data
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Regions
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Write Path
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Read Path
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HBase API
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HBase has a Java API
It is the only first class citizen
There are other programmatic interfaces
A REST interface allows HTTP access
A Thrift gateway allow non-Java programmatic access
There are non-native SQL interfaces
Apache Phoenix, Impala, Presto, Hive
Accessing HBase
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setConf(HBaseConfiguration.create(getConf()));
Connectionconnection=null;
Tabletable=null;
try{
//Definethetableandcolumnfamilyforthedata
TableNameTABLE_NAME=TableName.valueOf("hbasetable");
byte[]CF=Bytes.toBytes("colfamily");
//Connecttothetable
connection=ConnectionFactory.createConnection(getConf());
table=connection.getTable(TABLE_NAME);
//Createaputandaddcolumnstoit
Putp=newPut(Bytes.toBytes("rowkey"));
p.addColumn(CF,Bytes.toBytes("columnqual"),Bytes.toBytes(42.0d));
//Addthenewcolumntotherow
table.put(p);
}finally{
//closeeverythingdown
if(table!=null)
table.close();
if(connection!=null)
connection.close();
}
Puts
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//Definethetableandcolumnfamilyforthedata
TableNameTABLE_NAME=TableName.valueOf("hbasetable");
byte[]CF=Bytes.toBytes("colfamily");
//Connecttothetable
connection=ConnectionFactory.createConnection(getConf());
table=connection.getTable(TABLE_NAME);
//Createagetwiththerowkeyyouwant
Getg=newGet(Bytes.toBytes("rowkey"));
//Gettherowandbytestheforthecell
Resultresult=table.get(g);
byte[]value=result.getValue(CF,Bytes.toBytes("columnqual"));
//Yes,yourclientwillneedtoknowthetypeofdatainthecell
doubledoubleValue=Bytes.toDouble(value);
Gets
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Architecting HBase Solutions
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Architecting for a RDBMS is about relationships or
normalizing data
Architecting for HBase is about access patterns or
denormalizing data
Questions to ask:
How is data being accessed?
What is the fastest way to read or write data?
What is the optimal way to organize data?
Differences With RDBMS
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Abject Failure
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Treating HBase like a relational
database will lead to abject
failure
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Actual engineering goes into row key design
You only have one index or primary key
Getting this primary key right takes time and effort
You don't just use an auto-incrementing number
Multiple pieces of data are often in the row key
Row Keys
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Tables schemas require design and thought
The access pattern should be known ahead of time
General best practices:
Fewer, bigger (denormalized) tables
Spend more time designing up front
Use bulk loading for incremental or time series data
Schema Design
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Jesse Anderson (Smoking Hand)
jesse@smokinghand.com
@jessetanderson
Conclusion
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