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.
  - Managing Nodes
    Describes the Nodes page on the Control System.
  - Managing Roles
    Describes how to manage roles on a node.
    - Adding Roles to a Node
      Summarizes the process to add a role.
      - Adding a Role
        Describes how to add various roles to a Data Fabric node.
      - Adding a CLDB Role Using the CLI
        Describes how to add a CLDB role to an HPE Ezmeral Data Fabric node using the CLI.
      - Adding a ZooKeeper Role
        Describes how to add a ZooKeeper role to a Data Fabric node by using the CLI.
    - Removing Roles from a Node
      Describes how to remove a role from a node.
    - Assigning Roles to Nodes for Best Performance
      Guidelines to optimise the cluster's service layout for best performance.
  - Managing Services
    Synopsis on managing services.
  - Managing Disks
    Provides a brief overview of adding and removing disks from the HPE Ezmeral Data Fabric file system.
- 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.
- 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.

Adding a ZooKeeper Role

Describes how to add a ZooKeeper role to a Data Fabric node by using the CLI.

About this task

If you are increasing the number of ZooKeeper roles in the cluster, for example from one to three, shut down the cluster before you add the role to the nodes to prevent any problems. Then restart the cluster upon completion. Complete the following steps to add the ZooKeeper role to a node:

Procedure

Install the ZooKeeper package corresponding to the new role. For more information about packages, see Data Fabric Repositories and Packages.
To identify the ZooKeeper nodes in the cluster, run maprcli node listzookeepers.
Copy the tokens and all other directories needed from the existing nodes. You can find the list of files you need to copy in Enabling Security.

IMPORTANT Copying files as root user results in the files being unreadable. Make sure the copied files are readable as the cluster admin user.
On all nodes in the cluster where you added the new ZooKeeper role, run configure.sh with the following options:
- -Z: This option specifies the list of ZooKeeper nodes.
- -R: This option uses all previously set configurations.
For example:
```
/opt/mapr/server/configure.sh -Z <all-nodes-including-new-one> -R
```
Restart the servies on all nodes:
1. Run the following command on all nodes to start or restart ZooKeeper:
```
systemctl restart mapr-zookeeper
```
2. Perform a rolling restart of ZooKeeper on all nodes. A rolling restart of ZooKeeper means restart ZooKeeper on each node, one at a time, pausing until the last restart finishes before beginning the next. Restart the ZooKeeper leader last.
3. Run the following command to verify that the new node joined the ZooKeeper quorum:
```
/opt/mapr/initscripts/zookeeper qstatus
```
4. Perform a rolling restart of Warden on all nodes. Warden picks up the new ZooKeeper node. Issue the following command on all nodes to restart Warden:
```
systemctl restart mapr-warden
```
Run maprcli node listzookeepers. The output should show all ZooKeeper nodes, including the node where the role was added.