About Release 7.7.0
This site contains documentation for HPE Ezmeral Data Fabric release 7.7.0, including installation, configuration, administration, and reference content, as well as content for the associated ecosystem components and drivers.
7.7.0 Installation
This section contains information about installing and upgrading HPE Ezmeral Data Fabric software. It also contains information about how to migrate data and applications from an Apache Hadoop cluster to a HPE Ezmeral Data Fabric cluster.
7.7.0 Data Fabric
HPE Ezmeral Data Fabric is the industry-leading data platform for AI and analytics that solves enterprise business needs.
7.7.0 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 data-fabric 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 HPE Ezmeral Data Fabric clusters.
- Administering Files and Directories
- Administering Tables
  Administration of the HPE Ezmeral Data Fabric Database is done primarily via the command line (maprcli) or with the Managed Control System (MCS). Regardless of whether the HPE Ezmeral Data Fabric Database table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. HPE Ezmeral Data Fabric Database administration is associated with tables, columns and column families, and table regions.
  - Managing Tables
    HPE Ezmeral Data Fabric Database supports two types of table: binary tables and JSON tables. This section covers how to create, edit, and delete tables, as well as how to set parameter values, display parameter values, grant permissions and access, replicate tables, and more using the Control System and the CLI.
  - Managing Column Families and Columns
    This section covers overviews of column families in binary tables and JSON tables, how to create column families, alter them, delete them, set permissions on them, and set and display parameter values.
  - Managing Column Family Fields and Field Permissions for JSON Tables
    This sections covers details for working with column family fields. Column family fields can be added to any existing JSON table, and column families comprise optional fields.
  - Managing Table Replication
    This section contains topics about setting up table replication and administering existing replicas.
    - Preparing Clusters for Table Replication
      Preparing clusters for table replication includes configuring gateways on destination clusters, configuring the mapr-clusters.conf file on the source cluster, and, if the clusters are secure, setting up secure communications between the clusters. After you prepare the clusters for table replication, you can setup replication between tables.
    - Setting Up Table Replication Using the CLI
      You can run the maprcli table replica autosetup command to set up primary-secondary or multi-master replication from an existing source table.
    - Adding Table Replicas
      Explains how to add table replicas using either the Control System, the CLI or the REST API.
    - Displaying the List of Table Replicas
      Describes how to view information on the table replicas using the Control System or the CLI.
    - Modifying Table Replica
      Explains how to edit the properties of a replica using the Control System and the CLI.
    - Removing Table Replicas
      Explains how to un-register one or more replicas using either the Control System or the CLI.
    - Pausing Table Replication
      Explains how to pause table replication of data from a source HPE Ezmeral Data Fabric Database binary or JSON table to a replica HPE Ezmeral Data Fabric Database binary or JSON table respectively using either the Control System or the CLI.
    - Resuming Table Replication
      Explains how to resume replication between a source HPE Ezmeral Data Fabric Database binary or JSON table and a replica of that table when the replication state is set to paused from the Control System or by the maprcli table replica add or the maprcli table replica pause command.
    - Adding a Column Family to a Replica
      Changes to the structure of a source table are not automatically replicated to replica table. You must complete the following steps to add a column family to a replica.
    - Viewing Active Table Replication Alarms
      Describes how to view active table replication alarms using the Control System and the CLI.
    - Managing Upstream Source for Table Replicas
    - Addressing High Memory File Server Alarm for JSON Table Replication
      The topic describes the troubleshooting steps for memory overflow issues with JSON tables where replication has been set up, secondary indexes have been created on the JSON table being replicated, and table row size less than 1 KB.
  - Managing Secondary Indexes
    Describes how to manage secondary indexes, including adding, deleting, and listing indexes, setting up your cluster for querying, and troubleshooting index usage.
  - Administering Change Data Capture
    This topic covers the Control System and maprcli tools for managing the Change Data Capture (CDC) feature.
  - Indexing HPE Ezmeral Data Fabric Database Binary Tables with Elasticsearch
    As of with MapR 6.0, HPE Ezmeral Data Fabric Database Elastic Search integration capability is deprecated and no longer available in the HPE Ezmeral Data Fabric Database product.
- Administering Streams
- Administering Data Fabric Gateways
  A HPE Ezmeral Data Fabric gateway mediates one-way communication between a source HPE Ezmeral Data Fabric cluster and a destination cluster. You can replicate HPE Ezmeral Data Fabric Database tables (binary and JSON) and HPE Ezmeral Data Fabric Streams streams. HPE Ezmeral Data Fabric 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 Data Access Gateway
  The HPE Ezmeral Data Fabric Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the HPE Ezmeral Data Fabric 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
  Lists the common errors and their solutions.
- Best Practices for Backing Up HPE Ezmeral Data Fabric Information
  Lists the best practices and performance considerations to follow when backing up HPE Ezmeral Data Fabric information.
- IPv6 Support in Data Fabric
  Describes the IPv6 support feature for Data Fabric.
7.7.0 Development
This section contains information related to application development for Ezmeral ecosystem components and HPE Ezmeral Data Fabric products, including the file system, Database (Key-Value and JSON), and Event Streams.
Other Docs
This section contains release-independent information, including: Installer documentation, Ecosystem release notes, interoperability matrices, security vulnerabilities, and links to other data-fabric version documentation.
Glossary
Definitions for commonly used terms in MapR Converged Data Platform environments.

Addressing High Memory File Server Alarm for JSON Table Replication

The topic describes the troubleshooting steps for memory overflow issues with JSON tables where replication has been set up, secondary indexes have been created on the JSON table being replicated, and table row size less than 1 KB.

About this task

When you are working with JSON tables and High File Server Memory alarm is raised during table replication that has been set up between the JSON tables, check if secondary indexes are created on the destination table and the table row size is smaller than 1 KB.

If all the aforementioned conditions are met, follow the steps given below to resolve the memory overflow issue.

Procedure

Check the table region size to identify tables with memory overflow by running the table region list command.
Use the table region split command to manually split destination table regions with memory overflow or high memory usage. Split until each table region size is equal to or lower than 512 MB. This is a remedial measure for the memory overflow problem.
Run the table edit command and reset the regionsizemb parameter on the destination table to 512 MB from the default 4 GB value. This is a preventive measure that helps with avoiding the Data Fabric file system from running out of memory during replication of JSON tables, where row size smaller than 1 KB and a secondary index has been created on the JSON table.