hbase-cheat-sheet.md

HBase cheat sheet

• distributed,
• column-oriented persistent multidimensional sorted map
• autoscale
• storing column-family into memory/disc
• disc = hdfs or filesystem
• column familty (limited number) can be configured to:
  • compress
  • versions count
  • TimeToLive 'veracity'
  • in memory/on disc
  • separate file
• key - is byte[], value is byte[]
• scan by key
• scan by keys range
• schema free
• each record has a version
• TableName - filename
• record looks like: RowKey ; ColumnFamilyName ; ColumnName ; Timestamp
  
• table can divide into number of regions (sorted be key with start...end keys and controlled by HMaster )
• region has default size 256Mb

data is sparse - a lot of column has null values
fast retrieving data by 'key of the row' + 'column name'
contains from: (HBase HMaster) *---> (HBase Region Server)

SQL for Hbase - Phoenix SQL

Why HBase

HBase Architecture

HBase ACID

logical view

phisical view

logical to phisical view

Table characteristics

Column-Family

manage HBase

start/stop hbase

$HBASE_HOME/bin/start-hbase.sh
$HBASE_HOME/bin/stop-hbase.sh

interactive shell

cheat sheet

$HBASE_HOME/bin/hbase shell

path to jars from hbase classpath

hbase classpath

commands

• list of the tables

list

• create table

create table 'mytable1'

• description of the table

descibe 'my_space:mytable1'

• count records

count 'my_space:mytable1'

• delete table

drop table 'mytable1'
disable table 'mytable1'

• iterate through a table, iterate with range

scan 'my_space:mytable1'
scan 'my_space:mytable1', {STARTROW=>"00223cfd-8b50-979d29164e72:1220", STOPROW=>"00223cfd-8b50-979d29164e72:1520"}

• save results into a file

echo " scan 'my_space:mytable1', {STARTROW=>"00223cfd-8b50-979d29164e72:1220", STOPROW=>"00223cfd-8b50-979d29164e72:1520"} " | hbase shell > out.txt

• insert data, update data

put 'mytable1', 'row0015', 'cf:MyColumnFamily2', 'my value 01'

• read data

get 'mytable1', 'row0015'

Java

• java examples from google

java app

java \
    -cp /opt/cloudera/parcels/SPARK2/lib/spark2/jars/*:`hbase classpath`:{{ deploy_dir }}/lib/ingest-pipeline-orchestrator-jar-with-dependencies.jar \
    -Djava.security.auth.login.config={{ deploy_dir }}/res/deploy.jaas \
    com.bmw.ad.ingest.pipeline.orchestrator.admin.TruncateSessionEntriesHelper \
    --hbase-zookeeper {{ hbase_zookeeper }} \
    --ingest-tracking-table-name {{ ingest_tracking_table }} \
    --file-meta-table-name {{ file_meta_table }} \
    --component-state-table-name {{ component_state_table }} \
    --session-id $1

scan values

  Scan scan = new Scan(Bytes.toBytes(startAndStopRow), Bytes.toBytes(startAndStopRow));
  scan.addColumn(FAMILY_NAME, COLUMN_NAME);
  // scan.setFilter(new FirstKeyOnlyFilter());
  ResultScanner scanner = this.table.getScanner(scan);
  try{
   for ( Result result : scanner) { // each next() call - RPC call to server
     System.out.println(result);
   }
  }finally{
   scanner.close(); // !!! IMPORTANT !!!
  }
}

get value

Get record = new Get(Bytes.toBytes("row_key"));
record.addColumn(bytes.toBytes("column_family"), bytes.toBytes("column_name"));
Result result = mytable1.get(record);
# or
byte[] value = result.getValue(Bytes.toBytes("column_family"),Bytes.toBytes("column_name"))

put record

Put row=new Put(Bytes.toBytes("rowKey"));
row.add(Bytes.toBytes("column_family"), Bytes.toBytes("column"), Bytes.toBytes("value1"));
table.put(row);

package com.learn.hbase.client;

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.util.Bytes;

public class PutHBaseClient {

public static void main(String[] args) throws IOException {

  Configuration conf = HBaseConfiguration.create();

  Connection connection = ConnectionFactory.createConnection(conf);
  Table table = connection.getTable(TableName.valueOf("test"));
  try {

    Put put1 = new Put(Bytes.toBytes("row1"));

    put1.addColumn(Bytes.toBytes("cf"), Bytes.toBytes("qual1"), Bytes.toBytes("ValueOneForPut1Qual1"));
    put1.addColumn(Bytes.toBytes("cf"), Bytes.toBytes("qual2"), Bytes.toBytes("ValueOneForPut1Qual2"));

    table.put(put1);

  } finally {
    table.close();
    connection.close();
  }

}

}

update record

• checkAndPut - compares the value with the current value from the hbase according to the passed CompareOp. CompareOp=EQUALS Adds the value to the put object if expected value is equal.
• checkAndMutate - compares the value with the current value from the hbase according to the passed CompareOp.CompareOp=EQUALS Adds the value to the rowmutation object if expected value is equal.
  row mutation example

RowMutations mutations = new RowMutations(row);
//add new columns
Put put = new Put(row);
put.add(cf, col1, v1);
put.add(cf, col2, v2);

Delete delete = new Delete(row);
delete.deleteFamily(cf1, now);

//delete column family and add new columns to same family
mutations.add(delete);
mutations.add(put);

table.mutateRow(mutations);

delete value

Delete row=new Delete(Bytes.toBytes("rowKey"));
row.deleteColumn(Bytes.toBytes("column_family"), Bytes.toBytes("column"));
table.delete(row);
# or
table.deleteColumn(Bytes.toBytes("column_family"), Bytes.toBytes("column"), timestamp)
table.deleteColumns(Bytes.toBytes("column_family"), Bytes.toBytes("column"), timestamp)
table.deleteFamily(Bytes.toBytes("column_family"))

batch operation

Put put = 
Get get = 

Object[] results = new Object[2];
table.batch(List.of(put, get), results);

create table

Configuration config = HbaseConfiguration.create();

HBaseAdmin admin = new HbaseAdmin(config);

HTableDescriptor tableDescriptor = new HTableDescriptor(Bytes.toBytes("my_table1"));
HColumnDescriptor columns = new HColumnDescriptor(Bytes.toBytes("column_family_1"));
tableDescriptor.addFamily(columns);
admin.createTable(tableDescriptor);
admin.isTableAvailable(Bytes.toBytes("my_table1"));