A collection of Dockerfiles extending uhopper/hadoop, for creating an Accumulo cluster. The following Accumulo components are provided:

• monitor
• tserver
• master
• gc

All images inherit from a common base that provides hadoop, zookeeper and accumulo installations in /opt/ and allows configuration through environment variables.

The Accumulo configuration is controlled via the following environment variable groups:

1. CORE_CONF: affects /etc/hadoop/core-site.xml
2. HDFS_CONF: affects /etc/hadoop/hdfs-site.xml
3. YARN_CONF: affects /etc/hadoop/yarn-site.xml
4. HTTPFS_CONF: affects /etc/hadoop/httpfs-site.xml
5. KMS_CONF: affects /etc/hadoop/KMS-site.xml
6. ACCUMULO_CONF: affects /opt/accumulo/conf/accumulo-site.xml

Accumulo properties are specified by setting an environment variable with the appropriate prefix in the form <PREFIX>_<PROPERTY>.

Due to restrictions imposed by docker and docker-compose on environment variable names the following substitutions are applied to property names:

• _ => .
• __ => _
• ___ => -

Following are some illustratory examples:

• CORE_CONF_fs_defaultFS: sets the fs.defaultFS property in core-site.xml
• ACCUMULO_CONF_instance_zookeeper_host: sets the instance.zookeeper.host property in accumulo-site.xml

Additionally the ACCUMULO_MEM_USAGE environment variable is used for bootstrapping the initial Accumulo configuration memory settings. It accepts values of 1GB, 2GB, 3GB, or 512MB.

Accumulo requires running HDFS and Zookeeper instances. HDFS can be configured by following the documentation at uhopper/hadoop, and Zookeeper using the official zookeeper image.