HPE Ezmeral Data Fabric 6.2 is In Maintenance and transitions to "End of Maintenance" in June 2024. Please see the latest documentation.

About Release 6.2
This site contains documentation for HPE Ezmeral Data Fabric release 6.2 including installation, configuration, administration, and reference content, as well as content for the associated bundled ecosystem components and drivers.
6.2 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.
6.2 Data Fabric
HPE Ezmeral Data Fabric is the industry-leading data platform for AI and analytics that solves enterprise business needs.
- HPE Ezmeral Data Fabric File Store
  HPE Ezmeral Data Fabric File Store is a distributed file system for data storage, data management, and data protection. File Store supports mounting and cluster access via NFS and FUSE-based POSIX clients (basic, platinum, or PACC) and also supports access and management via HDFS APIs.
- HPE Ezmeral Data Fabric Database
  HPE Ezmeral Data Fabric Database is an enterprise-grade, high-performance, NoSQL database management system that you can use for real-time, operational analytics.
- HPE Ezmeral Data Fabric Streams
  HPE Ezmeral Data Fabric Streams brings integrated publish and subscribe messaging to the Data Fabric Converged Data Platform.
  - Architecture
    Streams contain topics that have logical collections of messages.
  - Producers
    Producers are data-generating applications, such as sensors in automobiles or activity loggers in servers. Producers create messages with the collected data and publish the messages to HPE Ezmeral Data Fabric Streams topics, specifically, to HPE Ezmeral Data Fabric Streams topic-partitions.
  - Consumers
    Consumers are applications that you create such as analytics applications, reporting tools, or enterprise dashboards.
  - Stream Replication
    You can replicate streams to other data-fabric clusters worldwide, or to other streams within a data-fabric cluster.
    - Modes of Stream Replication
      You can replicate streams in one of two replication modes. You specify the mode per source-replica pair.
    - Replica Autosetup for Streams
      The option to automatically set up stream replication, also known as replica autosetup, performs the steps to set up and start the replication of streams. The replica autosetup option is available through the Control System and the CLI.
    - States of Stream Replication
      The replication state indicates when stream replication is in progress and it also displays the status of operations related to replica autosetup with directcopy. The maprcli stream replica list command displays the following replication states.
    - Security for Stream Replication
      Describes where security can be implemented for stream replication.
    - Gateways and Stream Replication
      When replicating streams, HPE Ezmeral Data Fabric Streams replicates messages that are published to a source stream. Gateways are services that receive messages from source streams and publish them in replica streams.
  - Stream Security
    The adminperm, copyperm, comsumeperm, produceperm, and topicperm security permissions protect topics in a stream from unauthorized access. In addition, data-fabric supports user impersonation.
- Kubernetes Interfaces for Data Fabric
  This section describes the Kubernetes Interfaces for Data Fabric, which include the Container Storage Interface (CSI) driver for multiple container-orchestration systems, and the FlexVolume driver for Kubernetes.
- Cluster Management
  Provides a synopsis of the various cluster components and their management.
- Performance
  Describes how to tune system performance, manage RDMA, and optimize CLDB tables.
- Security
  Provides an overview of the data-fabric security features.
- YARN
- Client Connections
  The following sections describe how a client connects to local and remote data-fabric clusters.
6.2 Administration
This section describes how to manage the nodes and services that make up a cluster.
6.2 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.

Modes of Stream Replication

You can replicate streams in one of two replication modes. You specify the mode per source-replica pair.

Asynchronous replication

In this replication mode, HPE Ezmeral Data Fabric Streams confirms to producers that messages are published after the messages are placed in partitions. Messages are replicated in the background. Therefore, the latency of message publishing is not affected by the time required for the network round trip between the source cluster and the destination cluster.

This type of replication is well-suited for clusters that are geographically separated in wide-area networks.

Asynchronous replication is the default replication mode.

Synchronous replication

In this replication mode, HPE Ezmeral Data Fabric Streams confirms to producers that messages have been placed in partitions only after the messages are sent to a gateway in the destination cluster.

Due to the confirmations that HPE Ezmeral Data Fabric Streams receives on source clusters, synchronous replication is especially well-suited for creating a backup of your data for disaster recovery.

When the latency of a replication stream is high, HPE Ezmeral Data Fabric Streams switches to asynchronous replication temporarily so that producers are not blocked indefinitely. After the latency is sufficiently reduced, HPE Ezmeral Data Fabric Streams switches back to synchronous replication.

The same switching from synchronous to asynchronous replication occurs if all gateways fail. HPE Ezmeral Data Fabric Streams does not resume synchronous replication until a new gateway is established or at least one of the failed gateways is restarted.