HPE Ezmeral Data Fabric 6.1.x is In Maintenance and transitions to "End of Maintenance" in June 2024. Please see the latest documentation.

About MapR 6.1
This site contains the main documentation for Version 6.1 of the MapR Converged Data Platform, including installation, configuration, administration, and reference information.
6.1 Installation
This section contains information about installing and upgrading MapR software. It also contains information about how to migrate data and applications from an Apache Hadoop cluster to a MapR cluster.
6.1 MapR Data Platform
MapR Data Platform is the industry-leading data platform for AI and analytics that solves enterprise business needs.
6.1 Administration
This section describes how to manage the nodes and services that make up a cluster.
- Administering Users and Clusters
  Lists topics that help manage a MapR cluster.
- Administering Nodes
  Provides a synopsis of managing nodes in a cluster.
- 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 Database is done primarily via the command line (maprcli) or with the Managed Control System (MCS). Regardless of whether the MapR Database table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. MapR Database 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 Database tables (binary and JSON) and MapR Event Store For Apache Kafka 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 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.
  - maprcli and REST API Syntax
    This section provides information about the MapR command API. Most commands can be run on the command-line interface (CLI), or by making REST requests programmatically or in a browser.
  - Utilities
    Contains information about various scripts and utilities, that help setup, maintain, and monitor clusters.
  - Configuration Files
    This section contains reference information about various configuration files.
  - Alarms Reference
    The pages in this section provide details about all of the types of alarms.
    - User/Group Alarms
    - Cluster Alarms
    - Node Alarms
    - Table-Replication Alarms
    - Secondary Index Alarms
    - Volume Alarms
      - Compaction Failed
      - Data Unavailable
      - Data Under-Replicated
        Describe the alarm that is triggered when a volume is under replicated.
      - Warm-Tier Data Node Down
        Provides the resolution for the Warm-Tier Data Node Down alarm.
      - Data Under-Encoded
      - Data Below-Parity
      - Offload/Recall Failed
      - Inodes Limit Exceeded
      - Large Row
      - Mirror Failure
      - No Nodes in Topology
      - Snapshot Failure
      - Topology Almost Full
      - Topology Full Alarm
      - Volume Advisory Quota Alarm
      - Volume Become Master Stuck
      - Volume with Non-Local Containers
      - Volume Quota Alarm
  - MapR Data Platform Environment
    This section provides information associated with the MapR Data Platform environment.
  - Sample JSON File for Metering
    A sample metering JSON file for an 8-node cluster with no workloads enabled.
  - Metering Data Descriptions
    This table lists the metrics collected by the metering feature.
- Troubleshooting Cluster Administration
  Lists the common errors and their solutions.
- Best Practices for Backing Up MapR Information
  Lists the best practices and performance considerations to follow when backing up MapR information.
6.1 Development
This section contains information related to application development for Ezmeral ecosystem components and MapR Data Platform products, including the file system, Database (Key-Value and JSON), and Event Streams.
Other Docs
This section contains release-independent information, including: MapR Installer documentation, Ecosystem release notes, interoperability matrices, security vulnerabilities, and links to other MapR version documentation.
Glossary
Definitions for commonly used terms in MapR Converged Data Platform environments.

Data Under-Replicated

Describe the alarm that is triggered when a volume is under replicated.

UI Column: Replication Alarm
Logged As: VOLUME_ALARM_DATA_UNDER_REPLICATED
Meaning: The volume replication factor is lower than the desired replication factor set for the volume. This can be caused by failing disks or nodes, or the cluster may be running out of storage space.
Resolution: Investigate any nodes that are failing. You can see which nodes have failed by looking at the Node Health pane in the Overview page on the Control System. Determine whether it is necessary to add disks or nodes to the cluster. This alarm is generally raised when the nodes that store the volumes or replicas have not sent a heartbeat for five minutes. To prevent re-replication during normal maintenance procedures, MapR waits a specified interval (by default, one hour) before considering the node dead and re-replicating its data. You can control this interval by setting the cldb.fs.mark.rereplicate.sec parameter using the config save command. For additional troubleshooting information, see how to handle this alarm.