HPE Ezmeral Data Fabric 6.1.x is In Maintenance and transitions to "End of Maintenance" in June 2024. Please see the latest documentation.

About MapR 6.1
This site contains the main documentation for Version 6.1 of the MapR Converged Data Platform, including installation, configuration, administration, and reference information.
6.1 Installation
This section contains information about installing and upgrading MapR software. It also contains information about how to migrate data and applications from an Apache Hadoop cluster to a MapR cluster.
6.1 MapR Data Platform
MapR Data Platform is the industry-leading data platform for AI and analytics that solves enterprise business needs.
6.1 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 MapR 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 MapR clusters.
- Administering Files and Directories
- Administering Tables
  Administration of the MapR Database is done primarily via the command line (maprcli) or with the Managed Control System (MCS). Regardless of whether the MapR Database table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. MapR Database administration is associated with tables, columns and column families, and table regions.
- Administering Streams
- Administering MapR Gateways
  A MapR gateway mediates one-way communication between a source MapR cluster and a destination cluster. You can replicate MapR Database tables (binary and JSON) and MapR Event Store For Apache Kafka streams. MapR gateways also apply updates from JSON tables to their secondary indexes and propagate Change Data Capture (CDC) logs.
- Administering Services
  - Managing Services
    Synopsis on managing services.
  - Setting Up Central Configuration from the Command-Line
    Describes the concept of a central location where customized MapR configuration files for MapR services are stored.
  - Viewing CLDB Information
    Describes how to view CLDB information from the CLDB page, and provides an explanation of each field that the page displays.
  - Managing Drill
    Provides a short description on managing Drill services.
  - Managing the MapR NFS Service
    Provides an overview of managing the NFS service on a licensed cluster.
  - Managing MapR Data Platform POSIX Clients
    Provides a brief synopsis of MapR Data Platform POSIX clients.
    - MapR loopbacknfs POSIX Client
      Explains the differences between the MapR POSIX client and the Linux native NFS client.
      - Specifying Environment Variables
        Explains how to set environment variables on a client node.
      - Copying Configuration Files from a Server Node
      - Starting the mapr-loopbacknfs Service to Access a Cluster
        Describes the prerequisites and the process of starting the mapr-loopbacknfs service to access a secure cluster.
      - Securing the Mountpoint
      - Registering a POSIX Client with Additional Clusters
      - Configuring the MapR POSIX Client
        Explains how to set the number of RPC requests that POSIX clients send to a cluster.
      - Verifying MapR POSIX Client Licenses
        Use the Control System, to check how many MapR POSIX client licenses are available and being used.
      - Managing the mapr-loopbacknfs Service
        Explains how to start/stop and manage the loopbacknfs service from the command line.
      - Setting Up Aliases for NFS Exports
      - Troubleshooting mapr-loopbacknfs Service Issues
        Describes solutions for mapr-loopbacknfs issues.
    - MapR Data Platform FUSE-Based POSIX Client
      Provides a brief description of the FUSE-based POSIX client.
  - Managing the MAST Gateway
  - Configuring NodeManager Restart
  - Managing Jobs and Applications
- 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 MapR Data Access Gateway
  The MapR Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the MapR 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 MapR Information
  Lists the best practices and performance considerations to follow when backing up MapR information.
6.1 Development
This section contains information related to application development for Ezmeral ecosystem components and MapR Data Platform products, including the file system, Database (Key-Value and JSON), and Event Streams.
Other Docs
This section contains release-independent information, including: MapR Installer documentation, Ecosystem release notes, interoperability matrices, security vulnerabilities, and links to other MapR version documentation.
Glossary
Definitions for commonly used terms in MapR Converged Data Platform environments.

Configuring the MapR POSIX Client

Explains how to set the number of RPC requests that POSIX clients send to a cluster.

About this task

The default RPC requests configuration can negatively impact performance and memory. To avoid performance and memory issues, configure the number of outstanding RPC requests to the cluster to be 128.

Perform the following steps as the root user on each POSIX client machine:

Procedure

Issue the following commands to create the sunrpc.conf file under /etc/modprobe.d with the recommended configuration:
```
echo "options sunrpc tcp_slot_table_entries=128" >> /etc/modprobe.d/sunrpc.conf
echo "options sunrpc tcp_max_slot_table_entries=128" >> /etc/modprobe.d/sunrpc.conf
```
These commands enable the configuration to persist after a reboot of the NFS client machine.
Issue the following echo commands:
```
echo 128 > /proc/sys/sunrpc/tcp_slot_table_entries
echo 128 > /proc/sys/sunrpc/tcp_max_slot_table_entries
```
The commands enable the configuration to take effect after you remount the POSIX client to the MapR cluster.
Remount the POSIX client to the MapR cluster. For example, the following commands unmount and mount the NFS assuming that the cluster is mounted at /mapr:
```
umount /mapr
mount -o hard,nolock 127.0.0.1:/mapr /mapr
```
NOTE Failure to configure this property may result in the following error in /usr/local/mapr-loopbacknfs/log: ERROR nfsserver[38960] fs/nfsd/requesthandle.cc:791 0.0.0.0[0] cannot allocate more OncRpcContexts: [numDropped=2556001] dropping connection from nfsc=10.13.64.225:0

CentOS Troubleshooting Tip

After the reboot of the node, if the /proc/sys/sunrpc directory is not available, or if rpcidmapd is not running, start the rpcidmapd service using the following command: service rpcidmapd start.