This document contains information about HBase concepts and configurations. It discusses different modes of HBase operation including standalone, pseudo-distributed, and distributed modes. It also covers basic prerequisites for running HBase like Java, SSH, DNS, NTP, ulimit settings, and Hadoop for distributed mode. The document explains important HBase configuration files like hbase-site.xml, hbase-default.xml, hbase-env.sh, log4j.properties, and regionservers. It provides details on column-oriented versus row-oriented databases and discusses optimizations that can be made through configuration settings.

1. dwivedishashwat@gmail.com

2. QUERIES
Flow of Hbase read/write

5. QUERY
About Meter Logs:
It best suited for persistent and day by day
increasing data, as you data grows you can keep on
adding more nodes, and you have lot of facility,
process this data such as pig, hive and map-reduce.
You can run map-reduce and output the datasets
which can be indexed and used for faster search of
that huge data.

6. QUERY
Usibility
 HBase isn't suitable for every problem.
 First, make sure you have enough data. If you have hundreds of millions or
billions of rows, then HBase is a good candidate. If you only have a few
thousand/million rows, then using a traditional RDBMS might be a better
choice due to the fact that all of your data might wind up on a single node
(or two) and the rest of the cluster may be sitting idle.
 Second, make sure you can live without all the extra features that an
RDBMS provides (e.g., typed columns, secondary indexes, transactions,
advanced query languages, etc.) An application built against an RDBMS
cannot be "ported" to HBase by simply changing a JDBC driver, for
example. Consider moving from an RDBMS to HBase as a complete
redesign as opposed to a port.
 Third, make sure you have enough hardware. Even HDFS doesn't do well
with anything less than 5 DataNodes (due to things such as HDFS block
replication which has a default of 3), plus a NameNode.
 HBase can run quite well stand-alone on a laptop - but this should be
considered a development configuration only.

7. QUERY
Difference Between NoSQL DB and RDBMS
 NoSQL is a kind of database that doesn't have a fixed schema like a
traditional RDBMS does. With the NoSQL databases the schema is
defined by the developer at run time. They don't write normal SQL
statements against the database, but instead use an API to get the data
that they need. The NoSQL databases can usually scale across
different physical servers easily without needing to know which server
the data you are looking for is on.
 Why we should think of using it
 Durability
 Scalability on fly
 Distributed data
 Persistence etc.

8. QUERY
Row Oriented and Column oriented DBS
A column-oriented DBMS is a database
management system (DBMS) that stores data
tables as sections of columns of data rather than
as rows of data, like most relational DBMSs
1,Smith,Joe,40000;
2,Jones,Mary,50000;
3,Johnson,Cathy,44000;
1,2,3; Smith,Jones,Johnson;
Joe,Mary,Cathy;
40000,50000,44000;

9. A column-oriented database is different from
traditional row-oriented databases because of
how they store data. By storing a whole column
together instead of a row, you can minimize disk
access when selecting a few columns from a
row containing many columns. In row-oriented
databases there's no difference if you select just
one or all fields from a row.
ID
Nam
e
Age
1
Bhavi
n
29
2
Roge
r
30
This would be persisted in a conventional RDBMS as
follows -
1,Bhavin,29|2,Roger,30
In a column oriented DBMS this would be persisted as -
1,2|Bhavin,Roger|29,30

10. MORE DEPTH OF HBASE CONCEPTS

11. MODES OF HBASE OPERATION
Stand Alone :
In standalone mode, there is no distributed
file system and no Java services/daemons
are started. All mappers and reducers run
inside a single Java VM.
This mode is best suited for testing
purpose, and experimentations with
HBase.

12. MODES OF HBASE OPERATION…
Pseudo-Distributed Mode
Pseudo-distributed mode, Hbase processing is
distributed over all of the cores/processors on a
single machine. Hbase writes all files to the Hadoop
Distributed FileSystem (HDFS), and all services and
daemons communicate over local TCP sockets for
inter-process communication
A pseudo-distributed mode is simply a distributed
mode run on a single host. Use this configuration
testing and prototyping on HBase. Do not use this
configuration for production nor for evaluating
HBase performance

13. MODES OF HBASE OPERATION…
Distributed:
In distributed mode the daemons are
spread across all nodes in the cluster
Distributed modes require an instance
of the Hadoop Distributed File System
(HDFS)

14. BASIC PREREQUISITES
Java
SSH
DNS
NTP
ulimit and nproc
Hadoop for Distributed mode

15. BASIC PREREQUISITES IN DETAIL
Just like Hadoop, HBase requires at least java 6
from Oracle
ssh must be installed and sshd must be running
to use Hadoop's scripts to manage remote
Hadoop and HBase daemons. You must be
able to ssh to all nodes, including your local
node, using passwordless login
HBase uses the local hostname to self-report its
IP address. Both forward and reverse DNS
resolving must work

16. The clocks on cluster members should be in basic
alignments. Some skew is tolerable but wild skew could
generate odd behaviors. Run NTP on your cluster, or an
equivalent.
It uses a lot of files all at the same time. The default ulimit
-n -- i.e. user file limit -- of 1024 on most *nix systems is
insufficient Any significant amount of loading will lead
you to “java.io.IOException...(Too many open files)”
Hadoop for Distributed file system and mapreduce
processing.
BASIC PREREQUISITES IN DETAIL

17. HBASE CONFIGURATION FILES
hbase-site.xml
hbase-default.xml
hbase-env.sh
log4j.properties
regionservers

18. HBASE-DEFAULT.XML
Not all configuration options make it out
to hbase-default.xml. Configuration
that it is thought rare anyone would
change can exist only in code; the
only way to turn up such
configurations is via a reading of the
source code itself.

19. hbase.rootdir
 The directory shared by region servers and into which HBase persists.
 Default: file:///tmp/hbase-${user.name}/hbase
 hdfs://namenode:9000/hbase  For Distributed
hbase.master.port
 The port the HBase Master should bind to. Default is 60000
hbase.cluster.distributed
 The mode the cluster will be in. Possible values are false for standalone
mode and true for distributed mode
hbase.tmp.dir
 Temporary directory on the local filesystem.
 Default: /tmp/hbase-${user.name}
hbase.regionserver.port
 The port the HBase RegionServer binds to.
 Default: 60020
There are lot many parameters which need to be change for more
customized and optimized Hbase cluster.

20. HBASE-SITE.XML
Just as in Hadoop where you add site-
specific HDFS configuration to the
hdfs-site.xml file, for HBase, site
specific customizations go into the file
conf/hbase-site.xml. For the list of
configurable properties

21. <?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
<name>hbase.zookeeper.quorum</name>
<value>node1,node2,node3</value>
<description>The directory shared by RegionServers.
</description>
</property>
<property>
<name>hbase.zookeeper.property.dataDir</name>
<value>/export/zookeeper</value>
<description>Property from ZooKeeper's config zoo.cfg.
The directory where the snapshot is stored.
</description>

22. </property>
<property>
<name>hbase.rootdir</name>
<:value>hdfs//node0:8020/hbase</value>
<description>The directory shared by RegionServers.
</description>
</property>
<property>
<name>hbase.cluster.distributed</name>
<value>true</value>
<description>The mode the cluster will be in. Possible values are
false: standalone and pseudo-distributed setups with managed
Zookeeper
true: fully-distributed with unmanaged Zookeeper Quorum (see hbase-
env.sh)
</description>
</property>

23. HBASE-ENV.SH
Set HBase environment variables in this file.
Examples include options to pass the JVM on
start of an HBase daemon such as heap size and
garbarge collector configs. You can also set
configurations for HBase configuration, log
directories, niceness, ssh options, where to locate
process pid files, etc. Open the file at conf/hbase-
env.sh and peruse its content. Each option is fairly
well documented. Add your own environment
variables here if you want them read by HBase
daemons on startup.

24. export JAVA_HOME=/usr/lib//jvm/java-6-sun/
export HBASE_CLASSPATH=
export HBASE_HEAPSIZE=1000

25. LOG4J.PROPERTIES
Edit this file to change rate at which
HBase files are rolled and to
change the level at which HBase
logs messages.
Changes here will require a cluster
restart for HBase

26. REGIONSERVERS
In this file you list the nodes that will run
RegionServers.
Eg :
regionservernode1
regionservernode2
regionservernode3

27. CONFIGURATIONS
Required Configurations
 Java
 SSH
 DNS
 NTP
 ulimit and nproc
 Hadoop for Distributed mode
Recommended Configurations
 zookeeper.session.timeout
 The default timeout is three minutes (specified in milliseconds). This means
that if a server crashes, it will be three minutes before the Master notices the
crash and starts recovery
 Number of ZooKeeper Instances
 Compression
 Bigger Regions
 Balancer
 The balancer is a periodic operation which is run on the master to redistribute
regions on the cluster. It is configured via hbase.balancer.period and defaults to
300000
Still more are there, Just read more to have more optimized cluster.

28. GETTING STARTED WITH HBASE
Start HBase
./bin/start-hbase.sh starting Master, logging
to logs/hbase-user-master-example.org.out
Connect to your running HBase via the
shell
./bin/hbase shell HBase Shell
hbase(main):001:0>
And on this shell you can type shell
command which hbase provides to
perform various operations.

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 Right ?
http://db.csail.mit.edu/projects/cstore/abadi-sigmod08.pdf
https://cs.uwaterloo.ca/~aelhelw/papers/dolap11.pdf
https://ccp.cloudera.com/download/attachments/14549380/CDH2_In
stallation_Guide.pdf?version=1&modificationDate=134887134000
0
http://hbase.apache.org/
https://ccp.cloudera.com/display/CDHDOC/HBase+Installation
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