About Release 7.2
This site contains documentation for HPE Ezmeral Data Fabric release 7.2, including installation, configuration, administration, and reference content, as well as content for the associated ecosystem components and drivers.
7.2 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.
7.2 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 Object Store
  The HPE Ezmeral Data Fabric Object Store is a native object storage solution that efficiently stores objects and metadata for optimized access.
  - Entities and Resources
    Describes HPE Ezmeral Data Fabric Object Store entities, including domain, accounts, and resources (buckets, users, and access policies).
  - Access Policies
    Describes access policies and provides example policies. Also describes how Object Store evaluates access requests based on settings in access policies.
  - Getting Started with HPE Ezmeral Data Fabric Object Store
    Provides information to help get you started with HPE Ezmeral Data Fabric Object Store.
  - Supported S3 APIs
    Lists the Amazon S3-compatible APIs that HPE Ezmeral Object Store supports.
  - Supported Interfaces
    Lists the supported interfaces used to perform operations on HPE Ezmeral Data Fabric Object Store and provides links to additional information.
  - Administering Account Resources
    Describes how to set policies for controlling access.
  - Understanding Object Versioning
    Explains how versioning works for objects.
  - Using VIPs with Object Store
    Explains how to use VIPs for HPE Ezmeral Object Store, similar to VIPs in NFS.
  - Using Custom Signed Certificates with Object Store
    Describes how to run the HPE Ezmeral Data Fabric Object Store using custom certificates rather than the default self-signed certificates provided during installation.
  - Object Recovery Basics
    Explains object recovery modes.
  - Working with Bucket Volumes
    Describes how to identify the volume associated with a bucket for offloading, mirroring, and creating snapshots.
  - Traefik Load Balancing
    Describes how to use the Traefik load balancer to distribute the Object Store load across multiple MOSS servers in a release 7.0.0 or later Data Fabric cluster.
  - Operations
    Describes the operations that HPE Ezmeral Object Store supports.
  - Troubleshooting Object Store
    Provides methods for troubleshooting issues in Object Store.
  - Known Issues and Limitations
    Lists known issues and limitations in HPE Ezmeral Data Fabric Object Store.
- 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.
- 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.
7.2 Administration
This section describes how to manage the nodes and services that make up a cluster.
7.2 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.

Object Recovery Basics

Explains object recovery modes.

HPE Ezmeral Data Fabric Object Store features the ability to recover objects. Recovery operations include cleaning partially written objects, purging non-current versions of unversioned objects, and cleaning incomplete multi-part objects. Recovery also claims space by deleting dangling delete markers and objects marked for purge. In addition, recovery aggregates bucket statistics.

NOTE Recovery can run only on the node where the master copy of OLT table's first tablet is hosted. Recovery must be triggered using the alias of the node to which the bucket is assigned. Triggering recovery using a wrong node alias leads to a failure.

There are two recovery modes: mini and full.

Mini recovery mode: In a mini recovery, the system scans for buckets to recover every hour. The system picks up buckets that were created or modified in the last hour and examines them for any recovery to perform. The recovery deletes dangling delete markers.
Full recovery mode: In a full recovery, the system scans ALL buckets every week and examines them for any recovery to perform. Similar to the mini recovery, the system deletes all incomplete multipart uploads and dangling delete markers.

See mc admin recovery start and mc admin recovery stop to start and stop recovery.