dump balancerinfo

Returns detailed information about the storage pools on a cluster. If there are any active container moves, the command returns information about the source and destination storage pools.

The maprcli dump balancerinfo command enables you to see how much space is used in storage pools and to track active container moves. For best results, use the -json option when running dump balancerinfo from the command line.

The disk space balancer is a tool that balances disk space usage on a cluster by moving containers between storage pools. Whenever a storage pool is over 70% full (or a threshold defined by the cldb.balancer.disk.threshold.percentage parameter), the disk space balancer distributes containers to other storage pools that have lower utilization than the average for that cluster. The disk space balancer aims to ensure that the percentage of space used on all the disks in the node is similar. For more information, see Disk Space Balancer.

Syntax

CLI
maprcli dump balancerinfo
    [-cluster <cluster name>]
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.

Output

The maprcli dump balancerinfo command returns detailed information about the storage pools on a cluster. If there are any active container moves, the command returns information about the source and destination storage pools.

# maprcli dump balancerinfo -cluster my.cluster.com -json
{
        "timestamp":1337036566035,
        "status":"OK",
        "total":187,
        "data":[
{
                        "spid":"4bc329ce06752062004fa1a537abcdef",
                        "fsid":5410063549464613987,
                        "ip:port":"10.50.60.72:5660-",
                        "capacityMB":1585096,
                        "usedMB":1118099,
                        "percentage":70,
                        "fullnessLevel":"AboveAverage",
                        "inTransitMB":0,
                        "outTransitMB":31874
                },
{
                        "spid":"761fec1fabf32104004fad9630ghijkl",
                        "fsid":3770844641152008527,
                        "ip:port":"10.50.60.73:5660-",
                        "capacityMB":1830364,
                        "usedMB":793679,
                        "percentage":47,
                        "fullnessLevel":"BelowAverage",
                        "inTransitMB":79096,
                        "outTransitMB":0
                },

                ....


{
                        "containerid":4034,
                        "sizeMB":16046,
                        "From fsid":5410063549464613987,
                        "From IP:Port":"10.50.60.72:5660-",
                        "From SP":"4bc329ce06752062004fa1a537abcefg",
                        "To fsid":3770844641152008527,
                        "To IP:Port":"10.50.60.73:5660-",
                        "To SP":"761fec1fabf32104004fad9630ghijkl"
                },

Output fields

Field

Description

spid

The unique ID number of the storage pool.

fsid

The unique ID number of the file server. The FSID identifies an MapR Filesystem instance or a node that has MapR Filesystem running in the cluster. Typically, each node has a group of storage pools, so the same FSID will correspond to multiple SPIDs.

ip:port

The host IP address and MapR Filesystem port.

capacityMB

The total capacity of the storage pool (in MB).

usedMB

The amount of space used on the storage pool (in MB).

percentage

The percentage of the storage pool currently utilized. A ratio of the space used (usedMB) to the total capacity (capacityMB) of the storage pool.

fullnessLevel

The fullness of the storage pool relative to the fullness of the rest of the cluster. Possible values are OverUsed, AboveAverage, Average, BelowAverage, and UnderUsed. For more information, see Monitoring storage pool space usage below.

inTransitMB

The amount of data (in MB) that the disk space balancer is currently moving into a storage pool.

outTransitMB

The amount of data (in MB) that the disk space balancer is currently moving out of a storage pool.

The following fields are returned only if the disk space balancer is actively moving one or more containers at the time the command is run.

Field

Description

containerid

The unique ID number of the container.

sizeMB

The amount of data (in MB) being moved.

From fsid

The FSID (file server ID number) of the source file server.

From IP:Port

The IP address and port number of the source node.

From SP

The SPID (storage pool ID) of the source storage pool.

To fsid

The FSID (file server ID number) of the destination file server.

To IP:Port

The IP address and port number of the destination node.

To SP

The SPID (storage pool ID number) of the destination storage pool.

Examples

Monitoring storage pool space usage

You can use the maprcli dump balancerinfo command to monitor space usage on storage pools.

# maprcli dump balancerinfo -json

....
{
                        "spid":"4bc329ce06752062004fa1a537abcefg",
                        "fsid":5410063549464613987,
                        "ip:port":"10.50.60.72:5660-",
                        "capacityMB":1585096,
                        "usedMB":1118099,
                        "percentage":70,
                        "fullnessLevel":"AboveAverage",
                        "inTransitMB":0,
                        "outTransitMB":31874
                },

Tracking active container moves

Using the maprcli dump balancerinfo command you can monitor the activity of the disk space balancer. Whenever there are active container moves, the command returns information about the source and destination storage pools.

# maprcli dump balancerinfo -json
      ....
      {
           "containerid":7840,
           "sizeMB":15634,
           "From fsid":8081858704500413174,
           "From IP:Port":"10.50.60.64:5660-",
           "From SP":"9e649bf0ac6fb9f7004fa19d20rstuvw",
           "To fsid":3770844641152008527,
           "To IP:Port":"10.50.60.73:5660-",
           "To SP":"fefcc342475f0286004fad963flmnopq"
       }

The example shows that a container (7840) is being moved from a storage pool on node 10.50.60.64 to a storage pool on node 10.50.60.73.

Tip: You can use the storage pool IDs (SPIDs) to search the CLDB and MapR Filesystem logs for activity (balancer moves, container moves, creates, deletes, etc.) related to specific storage pools.