Installing Accumulo

This document provides basic instructions for installing Accumulo. For detailed instructions, see the ‘In-depth Installation’ guide in the Accumulo documentation on the project website.

Either download or build a binary distribution of Accumulo from source code and unpack as follows.

tar xzf /path/to/accumulo-X.Y.Z-bin.tar.gz
cd accumulo-X.Y.Z

There are four scripts in the bin directory of the tarball distribution that are used to manage Accumulo:

accumulo - Runs Accumulo command-line tools and starts Accumulo processes
accumulo-service - Runs Accumulo processes as services
accumulo-cluster - Manages Accumulo cluster on a single node or several nodes
accumulo-util - Accumulo utilities for building native libraries, running jars, etc.

These scripts will be used in the remaining instructions to configure and run Accumulo. For convenience, consider adding accumulo-X.Y.Z/bin/ to your shell's path.

Configuring Accumulo

Accumulo requires running Zookeeper and HDFS instances which should be set up before configuring Accumulo.

The primary configuration files for Accumulo are accumulo.properties, accumulo-env.sh, and accumulo-client.properties which are located in the conf/ directory.

The accumulo.properties file configures Accumulo server processes (i.e tablet server, master, monitor, etc). Follow these steps to set it up:

Run accumulo-util build-native to build native code. If this command fails, disable native maps by setting tserver.memory.maps.native.enabled to false.
Set instance.volumes to HDFS location where Accumulo will store data. If your namenode is running at 192.168.1.9:8020 and you want to store data in /accumulo in HDFS, then set instance.volumes to hdfs://192.168.1.9:8020/accumulo.
Set instance.zookeeper.host to the location of your Zookeepers
(Optional) Change instance.secret (which is used by Accumulo processes to communicate) from the default. This value should match on all servers.

The accumulo-env.sh file sets up environment variables needed by Accumulo:

Set HADOOP_HOME and ZOOKEEPER_HOME to the location of your Hadoop and Zookeeper installations. Accumulo will use these locations to find Hadoop and Zookeeper jars and add them to your CLASSPATH variable. If you you are running a vendor-specific release of Hadoop or Zookeeper, you may need to modify how the CLASSPATH variable is built in accumulo-env.sh. If Accumulo has problems loading classes when you start it, run accumulo classpath -d to debug and print Accumulo's classpath.
Accumulo tablet servers are configured by default to use 1GB of memory (768MB is allocated to JVM and 256MB is allocated for native maps). Native maps are allocated memory equal to 33% of the tserver JVM heap. The table below can be used if you would like to change tserver memory usage in the JAVA_OPTS section of accumulo-env.sh:
Native? 512MB 1GB 2GB 3GB
Yes -Xmx384m -Xms384m -Xmx768m -Xms768m -Xmx1536m -Xms1536m -Xmx2g -Xms2g
No -Xmx512m -Xms512m -Xmx1g -Xms1g -Xmx2g -Xms2g -Xmx3g -Xms3g
(Optional) Review the memory settings for the Accumulo master, garbage collector, and monitor in the JAVA_OPTS section of accumulo-env.sh.

Native?	512MB	1GB	2GB	3GB
Yes	-Xmx384m -Xms384m	-Xmx768m -Xms768m	-Xmx1536m -Xms1536m	-Xmx2g -Xms2g
No	-Xmx512m -Xms512m	-Xmx1g -Xms1g	-Xmx2g -Xms2g	-Xmx3g -Xms3g

The accumulo-client.properties file is used by the Accumulo shell and can be passed to Accumulo clients to simplify connecting to Accumulo. Below are steps to configure it.

Set instance.name and instance.zookeepers to the Accumulo instance and zookeeper connection string of your instance.
Pick an authentication type and set auth.type accordingly. The most common auth.type is password which requires auth.principal to be set and auth.token to be set the password of auth.principal. For the Accumulo shell, auth.token can be commented out and the shell will prompt you for the password of auth.principal at login.

Initialization

Accumulo needs to initialize the locations where it stores data in Zookeeper and HDFS. The following command will do this.

accumulo init

The initialization command will prompt for the following information.

Instance name : This is the name of the Accumulo instance and its Accumulo clients need to know it inorder to connect.
Root password : Initialization sets up an initial Accumulo root user and prompts for its password. This information will be needed to later connect to Accumulo.

Run Accumulo

There are several methods for running Accumulo:

Run Accumulo processes using accumulo command which runs processes in foreground and will not redirect stderr/stdout. Useful for creating init.d scripts that run Accumulo.
Run Accumulo processes as services using accumulo-service which uses accumulo command but backgrounds processes, redirects stderr/stdout and manages pid files. Useful if you are using a cluster management tool (i.e Ansible, Salt, etc).
Run an Accumulo cluster on one or more nodes using accumulo-cluster (which uses accumulo-service to run services). Useful for local development and testing or if you are not using a cluster management tool in production.

Each method above has instructions below.

Run Accumulo processes

Start Accumulo processes (tserver, master, monitor, etc) using command below:

accumulo tserver

The process will run in the foreground. Use ctrl-c to quit.

Run Accumulo services

Start Accumulo services (tserver, master, monitor, etc) using command below:

accumulo-service tserver start

Run an Accumulo cluster

Before using the accumulo-cluster script, additional configuration files need to be created. Use the command below to create them:

accumulo-cluster create-config

This creates five files (masters, gc, monitor, tservers, & tracers) in the conf/ directory that contain the node names where Accumulo services are run on your cluster. By default, all files are configured to localhost. If you are running a single-node Accumulo cluster, theses files do not need to be changed and the next section should be skipped.

Multi-node configuration

If you are running an Accumulo cluster on multiple nodes, the following files in conf/ should be configured with a newline separated list of node names:

masters : Accumulo primary coordinating process. Must specify one node. Can specify a few for fault tolerance.
gc : Accumulo garbage collector. Must specify one node. Can specify a few for fault tolerance.
monitor : Node where Accumulo monitoring web server is run.
tservers: Accumulo worker processes. List all of the nodes where tablet servers should run in this file.
tracers : Optional capability. Can specify zero or more nodes.

The Accumulo, Hadoop, and Zookeeper software should be present at the same location on every node. Also the files in the conf directory must be copied to every node. There are many ways to replicate the software and configuration, two possible tools that can help replicate software and/or config are pdcp and prsync.

The accumulo-cluster script uses ssh to start processes on remote nodes. Before attempting to start Accumulo, passwordless ssh must be setup on the cluster.

Start cluster

After configuring and initializing Accumulo, use the following command to start the cluster:

accumulo-cluster start

First steps

Once you have started Accumulo, use the following command to run the Accumulo shell:

accumulo shell -u root

Use your web browser to connect the Accumulo monitor page on port 9995.

http://<hostname in conf/monitor>:9995/

Stopping Accumulo

When finished, use the following commands to stop Accumulo:

Stop Accumulo service: accumulo-service tserver stop
Stop Accumulo cluster: accumulo-cluster stop