6.0 Administration
This section describes how to manage the nodes and services that make up a cluster.
- Administering Users and Clusters
- Administering Nodes
- Administering Volumes
  This section provide information about how to organize and manage data using volumes, a unique feature of MapR clusters.
- Administering Files and Directories
- Administering Tables
  Administration of the MapR-DB is done primarily via the command line (maprcli) or with the MapR Control System (MCS). Regardless of whether the MapR-DB table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. MapR-DB administration is associated with tables, columns and column families, and table regions.
- Administering Streams
- Administering MapR Gateways
  A MapR gateway mediates one-way communication between a source MapR cluster and a destination cluster. You can replicate MapR-DB tables (binary and JSON) and MapR-ES streams. MapR gateways also apply updates from JSON tables to their secondary indexes and propagate Change Data Capture (CDC) logs.
- Administering Services
- Monitoring the Cluster
  This section describes how to monitor the health and performance of a MapR cluster.
- Configuring Security
  Describes how to configure MapR security and manage secure clusters.
- Managing Secure Clusters
  Provides procedures that will enable you to use MapR clusters securely.
- Administering the MapR Data Access Gateway
  The MapR Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the MapR cluster. This section describes considerations when upgrading the service, how to modify configuration settings, and how to administer and manage the service.
- Planning for High Availability
- Administrator's Reference
  This section contains in-depth reference information for the administrator.
- Troubleshooting Cluster Administration
- Best Practices for Backing Up MapR Information

Allocating Memory for Nodes

When you run configure.sh on a node, warden allocates memory for the operating system, mfs service, MapR Hadoop services, and applications using the settings in the warden.conf and warden.<servicename>.conf file.

Warden allocates memory to the following components in the following order:

Operating system
mfs service
MapR Hadoop services
Applications, such as YARN applications
If the node only runs MapR-FS, NFS, and gateway, then 85% of all memory is allocated to MapR-FS

NOTE: In general, modify the settings in the warden files only under certain circumstances. If you modify the values in warden.conf or a warden.<servicename>.conf file, you must restart warden. Otherwise, updated parameters will not be used to allocate resources.