Apache Accumulo - Installation

Introduction:

Accumulo is a sorted, distributed key-value system built on top of Apache Hadoop, ZooKeeper, and Apache Thrift. Accumulo has cell-level access labels and a server-side programming mechanisms.

We will cover the following info regarding Accumulo database:

·         Installation and configuration of Accumulo.

·         Running Accumulo. 

·         Example of usage.

·         Java API

Installation and configuration of Accumulo:

1.        Tool chain requirements for Accumulo are: Java (1.6 and higher) Hadoop, Zookeeper (3.3.3 and higher). In this tutorial we use Java version 1.7.0, Hadoop version 1.0.3, and Zookeeper version 3.4.5.

2.        Download Accumulo files from here: http://accumulo.apache.org/downloads/.

3.        Extract Accumulo files. e.g. to /specific/disk1/temp/Accumulo/.

4.        Download Zookeeper from http://zookeeper.apache.org/.

5.        Extract Zookeeper files. e.g. to /specific/disk1/temp/Zookeeper/.

6.        Go to the conf folder in the zookeeper directory and create a file called zoo.cfg.

Insert the following lines inside zoo.cfg:

tickTime=2000

maxClientCnxns=100

dataDir=/var/zookeeper

clientPort=2181

# change the var instance to the place you would like zookeeper data file to be placed

# e.g dataDir=/specific/disk1/temp/zookeeper/conf/zookeeper

Save the file and close it.

7.        Download Hadoop from http://hadoop.apache.org/.

8.        Extract Hadoop files. e.g. to /specific/disk1/temp/Hadoop/.

9.        Go to the conf folder in the hadoop directory and edit the following files:

·            Insert the following lines inside core-site.xml:

<configuration>

<property>

<name>fs.default.name</name>

<value>hdfs://localhost:9000</value>

</property>

</configuration>

·            Insert the following lines inside hdfs-site.xml:

<configuration>

<property>

<name>dfs.replication</name>

<value>1</value>

</property>

</configuration>

·            Insert the following lines inside mapred-site.xml:

<configuration>

<property>

<name>mapred.job.tracker</name>

<value>localhost:9001</value>

</property>

</configuration>

·            If you would like to change the default place for Hadoop to deploy local data files insert the following lines inside core-site.xml:

<configuration>

<property>

<name> dfs.data.dir</name>

<value>"DesignatedPath"</value>

</property>

</configuration>

           

10.     Go to the conf folder in the Accumulo directory and copy one of the configuration available in the conf/examples folder to conf folder:

e.g: "cp conf/examples/512MB/native-standalone/* conf"

If you are configuring a larger cluster you will need to create the configuration files yourself and propagate the changes to the $ACCUMULO_HOME/conf directories:

·         Create a "slaves" file in $ACCUMULO_HOME/conf/.

This is a list of machines where tablet servers and loggers will run.

·         Create a "masters" file in $ACCUMULO_HOME/conf/.

This is a list of machines where the master server will run. 

·         Create conf/accumulo-env.sh following the template of example/3GB/native-standalone/accumulo-env.sh.

11.     Edit the JAVA_HOME, HADOOP_HOME, and ZOOKEEPER_HOME values in conf/accumulo-env.sh and point each of them to their home folder location accordingly:

e.g: ZOOKEEPER_HOME=/specific/disk1/temp/zookeeper

12.     Edit conf/accumulo-site.xml and set the zookeeper servers in the

instance.zookeeper.host property:

 

Edit the value of the property to be the ip's of the machines to run zookeeper (you need at least one computer running zookeeper)

E.g:         1 zookeeper configuration:

<property>

      <name>instance.zookeeper.host</name>

      <value>132.67.104.169:2181</value>

      <description>comma separated list of zookeeper servers</description>

    </property>

E.g:         2 zookeeper configuration:

<property>

      <name>instance.zookeeper.host</name>

      <value>132.67.104.169:2181,132.67.104.158:2181</value>

      <description>comma separated list of zookeeper servers</description>

    </property>

Running Accumulo:

1.        Now let's bring Accumulo server.

Once zookeeper and Hadoop are configured correctly on the machine you may start Zookeeper, Hadoop and Accumulo servers.

Run Zookeeper: bin/zkServer.sh start (you may stop it with: bin/zkServer.sh stop)

 

Run Hadoop:

o    bin/hadoop namenode –format

o    bin/start-all.sh (you may stop it with: bin/stop-all.sh)

 

Run Accumulo:

o    bin/accumulo init (enter the instance id and password in our example we set it to accum/accum)

o    bin/start-all.sh (you may stop it with: bin/stop-all.sh)

2.        You may check that Hadoop runs correctly through the monitor page:

http://localhost:50070

This should look like:

 

Except the port number in our case will be 50070.

3.        You may check that Accumulo runs correctly through the monitor page:

http://localhost:50095

This should look like: