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.
    - Stream Design
      Streams are created in volumes and contain topics, which in turn, contain messages. Security, replication, retention, and compression policies are applied at the stream-level.
    - Stream Topics
      Topics are created in streams and contain logical collections of messages. These collections of messages are published to partitions in the topic.
    - Topic Messages
      Messages are key/value pairs, where keys are optional. The values contain the data payload, which can be text, images, video files, or any other types of data.
      - Logical Schema of Messages
        Each message has the same logical schema: _id, topic, partition, offset, timestamp, producer, key, and value.
      - Time-to-Live for Messages
        The time-to-live (TTL) for messages means that messages persist in the partitions of a stream topic for a specific time period. During that time, messages can be read or re-read by consumers. Once the TTL for a message expires, the message is marked for deletion.
      - Life of a Message
        To show how the HPE Ezmeral Data Fabric Streams concepts fit together, here is an example of the flow of one message from a producer to a consumer.
      - Log Compaction
        Log compaction purges previous, older messages that were published to a topic-partition and retains the latest version of the record.
  - 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.
  - 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.

Topic Messages

Messages are key/value pairs, where keys are optional. The values contain the data payload, which can be text, images, video files, or any other types of data.

Messages are published into topic partitions by Producer applications and are read by Consumer applications. All messages published to HPE Ezmeral Data Fabric Streams are persisted, allowing future consumers to “catch-up” on processing and analytics applications to process historical data. See Producers and Consumers for more information.

Offsets

Messages are assigned offsets when published to partitions. Offsets are monotonically increasing and are local to partitions. The order of messages is preserved within individual partitions, but not across partitions.

NOTE In data-fabric version 6.0 and later, the message offset in a partition starts from zero (0). If you are upgrading and did not enable the HPE Ezmeral Data Fabric Database/HPE Ezmeral Data Fabric Streams feature mfs.feature.db.streams.v6.support, the message offset in a partition starts from one (1).