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
- 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.
  - maprcli and REST API Syntax
    This section provides information about the MapR command API. Most commands can be run on the command-line interface (CLI), or by making REST requests programmatically or in a browser.
  - Utilities
    Contains information about various scripts and utilities, that help setup, maintain, and monitor clusters.
    - configure.sh
      Describes the syntax and parameters of the configure.sh script that you run for a number of tasks including setting up MapR client nodes, and configuring services for a node.
    - configure-crosscluster.sh
      Use the configure-crosscluster.sh utility to set up cross-cluster security between two clusters.
    - cldbguts
      Monitors the activity of the Container Location Database (CLDB). This utility prints information about the CLDB service that is running on the node from which you run the utility.
    - disksetup
      Describes the disksetup command that formats disks for use by MapR storage.
    - ectool
      Dumps or checks the validity of the stripelets in the backend volume that is associated with the volume configured for warm tiering.
    - expandaudit
      Describes how to use the expandaudit utility to expand IDs captured in the audit logs to their corresponding names.
    - fcdebug
      Dynamically sets the log level to debug a library.
    - fsck
      Detects and fixes inconsistencies in the filesystem.
    - gfsck
      Describes how you can use the gfsck command, under the supervision of Map R Support or Engineering, to perform consistency checks and appropriate repairs on a volume, or a volume snapshot.
    - guts
      guts is a tool to measure/analyse performance. In the default mode, it prints one line every second, and counts the number of operations or bytes-processed in one second intervals. guts is an internal utility, and is subject to change without notice.
    - manageSSLKeys.sh
      Use the manageSSLKeys.sh utility to create and manage SSL certificates.
    - mapr-support-collect.sh
      Collects information about a cluster's recent activity, to help MapR Support diagnose problems.
    - mapr-support-dump.sh
      Collects node and cluster-level information for the node on which you invoke the script.
    - maprlogin
      Authenticates logins to secure MapR clusters.
    - mrconfig
      The mrconfig commands let you create, remove, and manage storage pools, disk groups, and disks; and provide information about containers.
      - mrconfig cntr
        Discusses the mrconfig cntr commands that allow you to manage containers and container replicas.
      - mrconfig dbinfo
        Each instance of the file server on a node is responsible for processing and tracking activities that result from running database commands. The mrconfig dbinfo command displays information about the activities, including information related to containers, tablets, storage pools, tags, and threads processing operations on tables.
      - mrconfig dg
        This section discusses the mrconfig dg commands that allow you to configure disk groups.
      - mrconfig disk
        This section discusses the mrconfig disk commands.
      - mrconfig info
        The mrconfig info commands provide information about memory, threads, volumes, containers and other information about the MapR file system.
        mrconfig info containerchain
        mrconfig info containerlist
        mrconfig info containers
        The mrconfig info containers command displays information about containers.
        mrconfig info dumpcontainers
        mrconfig info fsstate
        mrconfig info fsthreads
        mrconfig info mastgateway
        mrconfig info nfsthreads
        mrconfig info orphanagecount
        mrconfig info orphanlist
        mrconfig info replication
        mrconfig info slabs
        mrconfig info threads
        mrconfig info volume snapshot
        mrconfig info volume mastgateway
      - mrconfig mastgateway
        This section describes the mrconfig mastgateway commands that allow you to test PUT, GET, and DELETE operations on the corresponding tier.
      - mrconfig sp
        The mrconfig sp commands create and control storage pools.
    - mrdirectorystats
      Prints the space usage for each directory, for a container.
    - mrfscmd
      Returns the path to the file specified by ID (fid).
    - pullcentralconfig
      Pulls master configuration files from /var/mapr/configuration on the cluster to the local disk, on each node.
    - stubfuse
      Simulates a FUSE mount point to determine its read and write performance.
  - Configuration Files
    This section contains reference information about various configuration files.
  - Alarms Reference
    The pages in this section provide details about all of the types of alarms.
  - MapR Data Platform Environment
    This section provides information associated with the MapR Data Platform environment.
  - Sample JSON File for Metering
    A sample metering JSON file for an 8-node cluster with no workloads enabled.
  - Metering Data Descriptions
    This table lists the metrics collected by the metering feature.
- 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.

mrconfig info containerchain

The mrconfig info containerchain command displays the containerchain for a given container. Example:

$ /opt/mapr/server/mrconfig info containerchain 2050
Container 2050 prev 256000049 next 0.
Container 256000049 prev 0 next 2050.

See mrconfig for instructions on running mrconfig commands.

Syntax

mrconfig [-h <host>] [-p <port>] info containerchain <cid>

    <cid>

Parameters

Parameter	Description
-h	host IP address; default `127.0.0.1`
-p	The MapR File System port; default `5660`
cid	The container identifier

Tip:

Use the mrconfig info dumpcontainers command to find the container identifiers on a node.

Examples

Find the containerchain for a container with a cid of 2049 on a local node

/opt/mapr/server/mrconfig info containerchain 2049

Find the containerchain for a container with a cid of 2049 on a remote node with an IP address of xx.xx.xx.xx

/opt/mapr/server/mrconfig -h xx.xx.xx.xx info containerchain 2049