Manage HDInsight clusters by using the Apache Ambari REST API

Članak
05/22/2024

Learn how to use the Apache Ambari REST API to manage and monitor Apache Hadoop clusters in Azure HDInsight.

What is Apache Ambari

Apache Ambari simplifies the management and monitoring of Hadoop clusters by providing an easy to use web UI backed by its REST APIs. Ambari is provided by default with Linux-based HDInsight clusters.

Prerequisites

A Hadoop cluster on HDInsight. See Get Started with HDInsight on Linux.
Bash on Ubuntu on Windows 10. The examples in this article use the Bash shell on Windows 10. See Windows Subsystem for Linux Installation Guide for Windows 10 for installation steps. Other Unix shells work as well. The examples, with some slight modifications, can work on a Windows Command prompt. Or you can use Windows PowerShell.
jq, a command-line JSON processor. See https://stedolan.github.io/jq/.
Windows PowerShell. Or you can use Bash.

Base Uniform Resource Identifier for Ambari REST API

The base Uniform Resource Identifier (URI) for the Ambari REST API on HDInsight is https://CLUSTERNAME.azurehdinsight.net/api/v1/clusters/CLUSTERNAME, where CLUSTERNAME is the name of your cluster. Cluster names in URIs are case-sensitive. While the cluster name in the fully qualified domain name (FQDN) part of the URI (CLUSTERNAME.azurehdinsight.net) is case-insensitive, other occurrences in the URI are case-sensitive.

Authentication

Connecting to Ambari on HDInsight requires HTTPS. Use the admin account name (the default is admin) and password you provided during cluster creation.

For Enterprise Security Package clusters, instead of admin, use a fully qualified username like username@domain.onmicrosoft.com.

Examples

Setup (Preserve credentials)

Preserve your credentials to avoid reentering them for each example. The cluster name is preserved in a separate step.

A. Bash
Edit the script by replacing PASSWORD with your actual password. Then enter the command.

export password='PASSWORD'

B. PowerShell

$creds = Get-Credential -UserName "admin" -Message "Enter the HDInsight login"

Identify correctly cased cluster name

The actual casing of the cluster name may be different than you expect. The following steps show the actual casing, and then store it in a variable for all later examples.

Edit the scripts to replace CLUSTERNAME with your cluster name. Then enter the command. (The cluster name for the FQDN isn't case-sensitive.)

export clusterName=$(curl -u admin:$password -sS -G "https://CLUSTERNAME.azurehdinsight.net/api/v1/clusters" | jq -r '.items[].Clusters.cluster_name')
echo $clusterName

# Identify properly cased cluster name
$resp = Invoke-WebRequest -Uri "https://CLUSTERNAME.azurehdinsight.net/api/v1/clusters" `
    -Credential $creds -UseBasicParsing
$clusterName = (ConvertFrom-Json $resp.Content).items.Clusters.cluster_name;

# Show cluster name
$clusterName

Parsing JSON data

The following example uses jq or ConvertFrom-Json to parse the JSON response document and display only the health_report information from the results.

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName" \
| jq '.Clusters.health_report'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.Clusters.health_report

Get the FQDN of cluster nodes

You may need to know the fully qualified domain name (FQDN) of a cluster node. You can easily retrieve the FQDN for the various nodes in the cluster using the following examples:

All nodes

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/hosts" \
| jq -r '.items[].Hosts.host_name'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/hosts" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.items.Hosts.host_name

Head nodes

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/HDFS/components/NAMENODE" \
| jq -r '.host_components[].HostRoles.host_name'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/HDFS/components/NAMENODE" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.host_components.HostRoles.host_name

Worker nodes

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/HDFS/components/DATANODE" \
| jq -r '.host_components[].HostRoles.host_name'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/HDFS/components/DATANODE" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.host_components.HostRoles.host_name

Zookeeper nodes

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/ZOOKEEPER/components/ZOOKEEPER_SERVER" \
| jq -r ".host_components[].HostRoles.host_name"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/ZOOKEEPER/components/ZOOKEEPER_SERVER" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.host_components.HostRoles.host_name

Get the internal IP address of cluster nodes

The IP addresses returned by the examples in this section aren't directly accessible over the internet. They're only accessible within the Azure Virtual Network that contains the HDInsight cluster.

For more information on working with HDInsight and virtual networks, see Plan a virtual network for HDInsight.

To find the IP address, you must know the internal fully qualified domain name (FQDN) of the cluster nodes. Once you have the FQDN, you can then get the IP address of the host. The following examples first query Ambari for the FQDN of all the host nodes. Then queries Ambari for the IP address of each host.

for HOSTNAME in $(curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/hosts" | jq -r '.items[].Hosts.host_name')
do
    IP=$(curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/hosts/$HOSTNAME" | jq -r '.Hosts.ip')
  echo "$HOSTNAME <--> $IP"
done

$uri = "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/hosts" 
$resp = Invoke-WebRequest -Uri $uri -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
foreach($item in $respObj.items) {
    $hostName = [string]$item.Hosts.host_name
    $hostInfoResp = Invoke-WebRequest -Uri "$uri/$hostName" `
        -Credential $creds -UseBasicParsing
    $hostInfoObj = ConvertFrom-Json $hostInfoResp
    $hostIp = $hostInfoObj.Hosts.ip
    "$hostName <--> $hostIp"
}

Get the default storage

HDInsight clusters must use an Azure Storage Account or Data Lake Storage as the default storage. You can use Ambari to retrieve this information after the cluster has been created. For example, if you want to read/write data to the container outside HDInsight.

The following examples retrieve the default storage configuration from the cluster:

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" \
| jq -r '.items[].configurations[].properties["fs.defaultFS"] | select(. != null)'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.items.configurations.properties.'fs.defaultFS'

Important

These examples return the first configuration applied to the server (service_config_version=1) which contains this information. If you retrieve a value that has been modified after cluster creation, you may need to list the configuration versions and retrieve the latest one.

The return value is similar to one of the following examples:

wasbs://CONTAINER@ACCOUNTNAME.blob.core.windows.net - This value indicates that the cluster is using an Azure Storage account for default storage. The ACCOUNTNAME value is the name of the storage account. The CONTAINER portion is the name of the blob container in the storage account. The container is the root of the HDFS compatible storage for the cluster.
abfs://CONTAINER@ACCOUNTNAME.dfs.core.windows.net - This value indicates that the cluster is using Azure Data Lake Storage Gen2 for default storage. The ACCOUNTNAME and CONTAINER values have the same meanings as for Azure Storage mentioned previously.

adl://home - This value indicates that the cluster is using Azure Data Lake Storage Gen1 for default storage.

To find the Data Lake Storage account name, use the following examples:

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" \
| jq -r '.items[].configurations[].properties["dfs.adls.home.hostname"] | select(. != null)'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.items.configurations.properties.'dfs.adls.home.hostname'

The return value is similar to ACCOUNTNAME.azuredatalakestore.net, where ACCOUNTNAME is the name of the Data Lake Storage account.

To find the directory within Data Lake Storage that contains the storage for the cluster, use the following examples:

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" \
| jq -r '.items[].configurations[].properties["dfs.adls.home.mountpoint"] | select(. != null)'

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations/service_config_versions?service_name=HDFS&service_config_version=1" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.items.configurations.properties.'dfs.adls.home.mountpoint'

The return value is similar to /clusters/CLUSTERNAME/. This value is a path within the Data Lake Storage account. This path is the root of the HDFS compatible file system for the cluster.

Note

The Get-AzHDInsightCluster cmdlet provided by Azure PowerShell also returns the storage information for the cluster.

Get all configurations

Get the configurations that are available for your cluster.

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName?fields=Clusters/desired_configs"

$respObj = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName`?fields=Clusters/desired_configs" `
    -Credential $creds -UseBasicParsing
$respObj.Content

This example returns a JSON document containing the current configuration for installed components. See the tag value. The following example is an excerpt from the data returned from a Spark cluster type.

"jupyter-site" : {
  "tag" : "INITIAL",
  "version" : 1
},
"livy2-client-conf" : {
  "tag" : "INITIAL",
  "version" : 1
},
"livy2-conf" : {
  "tag" : "INITIAL",
  "version" : 1
},

Get configuration for specific component

Get the configuration for the component that you're interested in. In the following example, replace INITIAL with the tag value returned from the previous request.

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations?type=livy2-conf&tag=INITIAL"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations?type=livy2-conf&tag=INITIAL" `
    -Credential $creds -UseBasicParsing
$resp.Content

This example returns a JSON document containing the current configuration for the livy2-conf component.

Update configuration

Create newconfig.json.
Modify, and then enter the commands as follows:

Replace livy2-conf with the new component.

Replace INITIAL with actual value retrieved for tag from Get all configurations.

A. Bash

curl -u admin:$password -sS -G "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations?type=livy2-conf&tag=INITIAL" \
| jq --arg newtag $(echo version$(date +%s%N)) '.items[] | del(.href, .version, .Config) | .tag |= $newtag | {"Clusters": {"desired_config": .}}' > newconfig.json

B. PowerShell
The PowerShell script uses jq. Edit C:\HD\jq\jq-win64 below to reflect your actual path and version of jq.

$epoch = Get-Date -Year 1970 -Month 1 -Day 1 -Hour 0 -Minute 0 -Second 0
$now = Get-Date
$unixTimeStamp = [math]::truncate($now.ToUniversalTime().Subtract($epoch).TotalMilliSeconds)
$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/configurations?type=livy2-conf&tag=INITIAL" `
  -Credential $creds -UseBasicParsing
$resp.Content | C:\HD\jq\jq-win64 --arg newtag "version$unixTimeStamp" '.items[] | del(.href, .version, .Config) | .tag |= $newtag | {"Clusters": {"desired_config": .}}' > newconfig.json

Jq is used to turn the data retrieved from HDInsight into a new configuration template. Specifically, these examples do the following actions:

Creates a unique value containing the string "version" and the date, which is stored in newtag.
Creates a root document for the new configuration.
Gets the contents of the .items[] array and adds it under the desired_config element.
Deletes the href, version, and Config elements, as these elements aren't needed to submit a new configuration.

Adds a tag element with a value of version#################. The numeric portion is based on the current date. Each configuration must have a unique tag.

Finally, the data is saved to the newconfig.json document. The document structure should appear similar to the following example:

{
  "Clusters": {
    "desired_config": {
      "tag": "version1552064778014",
      "type": "livy2-conf",
      "properties": {
        "livy.environment": "production",
        "livy.impersonation.enabled": "true",
        "livy.repl.enableHiveContext": "true",
        "livy.server.csrf_protection.enabled": "true",
          ....
      },
    },
  }
}

Edit newconfig.json.
Open the newconfig.json document and modify/add values in the properties object. The following example changes the value of "livy.server.csrf_protection.enabled" from "true" to "false".
```
"livy.server.csrf_protection.enabled": "false",
```
Save the file once you're done making modifications.

Submit newconfig.json.
Use the following commands to submit the updated configuration to Ambari.

curl -u admin:$password -sS -H "X-Requested-By: ambari" -X PUT -d @newconfig.json "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName"

$newConfig = Get-Content .\newconfig.json
$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName" `
    -Credential $creds -UseBasicParsing `
    -Method PUT `
    -Headers @{"X-Requested-By" = "ambari"} `
    -Body $newConfig
$resp.Content

These commands submit the contents of the newconfig.json file to the cluster as the new configuration. The request returns a JSON document. The versionTag element in this document should match the version you submitted, and the configs object contains the configuration changes you requested.

Restart a service component

At this point, the Ambari web UI indicates the Spark service needs to be restarted before the new configuration can take effect. Use the following steps to restart the service.

Use the following to enable maintenance mode for the Spark2 service:

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
-X PUT -d '{"RequestInfo": {"context": "turning on maintenance mode for SPARK2"},"Body": {"ServiceInfo": {"maintenance_state":"ON"}}}' \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" `
    -Credential $creds -UseBasicParsing `
    -Method PUT `
    -Headers @{"X-Requested-By" = "ambari"} `
    -Body '{"RequestInfo": {"context": "turning on maintenance mode for SPARK2"},"Body": {"ServiceInfo": {"maintenance_state":"ON"}}}'

Verify maintenance mode

These commands send a JSON document to the server that turns on maintenance mode. You can verify that the service is now in maintenance mode using the following request:

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" \
| jq .ServiceInfo.maintenance_state

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.ServiceInfo.maintenance_state

The return value is ON.

Next, use the following to turn off the Spark2 service:

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
-X PUT -d '{"RequestInfo":{"context":"_PARSE_.STOP.SPARK2","operation_level":{"level":"SERVICE","cluster_name":"CLUSTERNAME","service_name":"SPARK"}},"Body":{"ServiceInfo":{"state":"INSTALLED"}}}' \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" `
    -Credential $creds -UseBasicParsing `
    -Method PUT `
    -Headers @{"X-Requested-By" = "ambari"} `
    -Body '{"RequestInfo":{"context":"_PARSE_.STOP.SPARK2","operation_level":{"level":"SERVICE","cluster_name":"CLUSTERNAME","service_name":"SPARK"}},"Body":{"ServiceInfo":{"state":"INSTALLED"}}}'
$resp.Content

The response is similar to the following example:

{
    "href" : "http://10.0.0.18:8080/api/v1/clusters/CLUSTERNAME/requests/29",
    "Requests" : {
        "id" : 29,
        "status" : "Accepted"
    }
}

Important

The href value returned by this URI is using the internal IP address of the cluster node. To use it from outside the cluster, replace the 10.0.0.18:8080 portion with the FQDN of the cluster.

Verify request.
Edit the command below by replacing 29 with the actual value for id returned from the prior step. The following commands retrieve the status of the request:

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/requests/29" \
| jq .Requests.request_status

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/requests/29" `
    -Credential $creds -UseBasicParsing
$respObj = ConvertFrom-Json $resp.Content
$respObj.Requests.request_status

A response of COMPLETED indicates that the request has finished.

Once the previous request completes, use the following to start the Spark2 service.

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
-X PUT -d '{"RequestInfo":{"context":"_PARSE_.START.SPARK2","operation_level":{"level":"SERVICE","cluster_name":"CLUSTERNAME","service_name":"SPARK"}},"Body":{"ServiceInfo":{"state":"STARTED"}}}' \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" `
    -Credential $creds -UseBasicParsing `
    -Method PUT `
    -Headers @{"X-Requested-By" = "ambari"} `
    -Body '{"RequestInfo":{"context":"_PARSE_.START.SPARK2","operation_level":{"level":"SERVICE","cluster_name":"CLUSTERNAME","service_name":"SPARK"}},"Body":{"ServiceInfo":{"state":"STARTED"}}}'
$resp.Content

The service is now using the new configuration.

Finally, use the following to turn off maintenance mode.

curl -u admin:$password -sS -H "X-Requested-By: ambari" \
-X PUT -d '{"RequestInfo": {"context": "turning off maintenance mode for SPARK2"},"Body": {"ServiceInfo": {"maintenance_state":"OFF"}}}' \
"https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2"

$resp = Invoke-WebRequest -Uri "https://$clusterName.azurehdinsight.net/api/v1/clusters/$clusterName/services/SPARK2" `
    -Credential $creds -UseBasicParsing `
    -Method PUT `
    -Headers @{"X-Requested-By" = "ambari"} `
    -Body '{"RequestInfo": {"context": "turning off maintenance mode for SPARK2"},"Body": {"ServiceInfo": {"maintenance_state":"OFF"}}}'

Next steps

For a complete reference of the REST API, see Apache Ambari API Reference V1. See also, Authorize users for Apache Ambari Views

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