In a created E-MapReduce (EMR) cluster, you can run Admin Shell commands of Alluxio to manage and maintain files in Alluxio. This topic describes common administrative commands of Alluxio.
Prerequisites
- An EMR Hadoop cluster is created, and Alluxio is selected from the optional services when you create the cluster. For more information, see Create a cluster.
- You have logged on to the cluster. For more information, see Log on to a cluster.
Background information
The following table describes common administrative commands of Alluxio.
Command | Description |
---|---|
backup |
Backs up metadata in Alluxio. |
doctor |
Displays errors and alerts reported in Alluxio. |
report |
Displays information about clusters on which Alluxio is running. |
ufs |
Updates the attributes of an attached underlying storage. |
For more information, see Admin Command Line Interface.
backup
Backs up metadata in Alluxio.
- Syntax:
alluxio fsadmin backup [directory]
- Examples:
- Back up metadata to the default directory.
alluxio fsadmin backup
If the following information is returned, the metadata is backed up.Backup Host : emr-header-1.cluster-23**** Backup URI : hdfs://emr-header-1:9000/alluxio_backups/alluxio-backup-2021-06-01-1622547059762.gz Backup Entry Count : 25
- Back up metadata to the /tmp directory.
alluxio fsadmin backup /tmp
If the following information is returned, the metadata is backed up.Backup Host : emr-header-1.cluster-23**** Backup URI : hdfs://emr-header-1:9000/tmp/alluxio-backup-2021-06-01-1622547072114.gz Backup Entry Count : 25
- Back up metadata to the default directory.
doctor
Displays errors and alerts reported in Alluxio.
- Syntax:
alluxio fsadmin doctor [category]
Note The[category]
parameter is optional. If you do not specify this parameter, the errors and alerts of all types are displayed. Valid values of the[category]
parameter: configuration and storage. - Example: Display errors and alerts reported in Alluxio.
alluxio fsadmin doctor
If the following information is returned, no error or warning is displayed.All worker storage paths are in working state.
report
Displays information about clusters on which Alluxio is running.
- Syntax:
alluxio fsadmin report [category]
Note The[category]
parameter is optional. If you do not specify this parameter, only the summary information is displayed. Valid values of the[category]
parameter: capacity, metrics, summary, ufs, and jobservice. - Example: Display information about clusters on which Alluxio is running.
alluxio fsadmin report
Information similar to the following command output is returned:Alluxio cluster summary: Master Address: emr-header-1:1**** Web Port: 1**** Rpc Port: 1**** Started: 06-01-2021 14:07:08:420 Uptime: 0 day(s), 20 hour(s), 42 minute(s), and 57 second(s) Version: 2.5.0 Safe Mode: false Zookeeper Enabled: false Live Workers: 2 Lost Workers: 0 Total Capacity: 88.00GB Tier: MEM Size: 8.00GB Tier: SSD Size: 80.00GB Used Capacity: 320.00MB Tier: MEM Size: 64.00MB Tier: SSD Size: 256.00MB Free Capacity: 87.69GB
ufs
Updates the attributes of an attached underlying storage.
- Syntax:
alluxio fsadmin --mode <noAccess/readOnly/readWrite> <ufsPath>
- Example: Set the mode parameter to readOnly to prohibit write operations on the underlying
storage.
alluxio fsadmin ufs --mode readOnly hdfs://ns