dump containers

Returns information about containers in a cluster.

This command provides information about containers based on the following -type criteria:

  • offline - Returns information about containers that have no valid copies online. This command is useful when you need to find out exactly what data is offline (for example, when a "volume data unavailable" alarm is raised).
  • resync - Returns information about containers that are resynchronizing.
  • bm - Returns information about containers that are becoming master but are not yet master.
  • unused - Returns information about containers that are unused.
  • waiting - Returns information about containers that are waiting for a role.

A container is a unit of sharded storage in a MapR cluster. Every container in a MapR volume is either a name container or a data container. The name container is the first container in a volume and holds that volume's namespace and file chunk locations. Depending on its replication role, a name container may be either a master container (part of the original copy of the volume) or a replica container (one of the replicas in the replication chain).

Every data container is either a master container, an intermediate container, or a tail container.

Syntax

CLI
maprcli dump containers
    [ -cluster <cluster_name> ]
     -type offline|resync|bm|waiting|unused
Note: For best results, use the -json option from the command line.
REST
N/A

Parameters

Parameter

Description

cluster The cluster on which to run the command. If this parameter is omitted, the command is run on the same cluster where it is issued. In multi-cluster contexts, you can use this parameter to specify a different cluster on which to run the command.
type Specifies the type of information that is returned about the containers:
  • offline - Returns information about containers that have no valid copies online.
  • resync - Returns information about containers that are resynchronizing.
  • bm - Returns information about containers that are becoming master but are not yet master.
  • unused - Returns information about containers that are unused.
  • waiting - Returns information about containers that are waiting for a role.

Output fields

Field

Description

ContainerID

The unique ID number for the container.

Epoch

A sequence number that indicates the most recent copy of the container. The CLDB uses the epoch to ensure that an out-of-date copy cannot become the master for the container.

Master

The physical IP address and port number of the master copy. The master copy is part of the original copy of the volume.

ActiveServers

The physical IP address and port number of each active node on which the container resides.

InactiveServers

The physical IP address and port number of each inactive node on which the container resides.

UnusedServers

The physical IP address and port number of servers from which no "heartbeat" has been received for quite some time.

OwnedSizeMB

The size on disk (in MB) dedicated to the container.

SharedSizeMB

The size on disk (in MB) shared by the container.

LogicalSizeMB

The logical size on disk (in MB) of the container.

TotalSizeMB

The total size on disk (in MB) allocated to the container. Combines the Owned Size and Shared Size.

Mtime

The time of the last modification to the contents of the container.

NameContainer

Indicates if the container is the name container for the volume. If true, the container holds the volume's namespace information and file chunk locations.

VolumeName

The name of the volume.

VolumeId

The unique ID number of the volume.

VolumeReplication

The replication factor, the number of copies of a volume excluding the original.

VolumeMounted

Indicates whether the volume is mounted. If true, the volume is currently mounted. If false, the volume is not mounted.

Example

CLI
maprcli dump containers -type offline -cluster my.cluster -json

Output Samples

The following maprcli dump containers -type offline command returns information about all offline containers.

# maprcli dump containers -type offline -json
{
        "timestamp":1348174731389,
        "status":"OK",
        "total":11,
        "data":[
                {
                        "ContainerId":2060,
                        "Epoch":3,
                        "Master":"unknown ip (0)-0-VALID",
                        "ActiveServers":{

                        },
                        "InactiveServers":{

                        },
                        "UnusedServers":{
                                "IP:Port":"10.10.20.39:5660--3"
                        },
                        "OwnedSizeMB":"0 MB",
                        "SharedSizeMB":"0 MB",
                        "LogicalSizeMB":"0 MB",
                        "TotalSizeMB":"0 MB",
                        "NameContainer":"true"
                },
                {
                        "ContainerId":2185,
                        "Epoch":3,
                        "Master":"unknown ip (0)-0-VALID",
                        "ActiveServers":{

                        },
                        "InactiveServers":{

                        },
                        "UnusedServers":{
                                "IP:Port":"10.10.20.39:5660--3"
                        },
                        "OwnedSizeMB":"0 MB",
                        "SharedSizeMB":"0 MB",
                        "LogicalSizeMB":"0 MB",
                        "TotalSizeMB":"0 MB",
                        "NameContainer":"false"
                },
...

The following maprcli dump containers -type resync command returns information about containers that are resyncronizing.

# maprcli dump containers -type resync -json
{
        "timestamp":1438666159569,
        "timeofday":"2015-08-03 10:29:19.569 GMT-0700",
        "status":"OK",
        "total":1,
        "data":[
                {
                        "InstanceCount":1,
                        "ContainerId":2242,
                        "Epoch":4,
                        "Master":"10.10.103.30:5660--4-VALID",
                        "ActiveServers":{
                                "IP:Port":[
                                        "10.10.103.30:5660--4-VALID",
                                        "10.10.103.28:5660--4-VALID",
                                        "10.10.103.29:5660--3-RESYNC"
                                ]
                        },
                        "InactiveServers":{

                        },
                        "UnusedServers":{

                        },
                        "OwnedSizeMB":"0 MB",
                        "SharedSizeMB":"0 MB",
                        "LogicalSizeMB":"0 MB",
                        "TotalSizeMB":"0 MB",
                        "NameContainer":"true",
                        "CreatorContainerId":0,
                        "CreatorVolumeUuid":""
                }
        ]