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Run Apache Sqoop jobs with Azure PowerShell in HDInsight

  • Artikkeli

Learn how to use Azure PowerShell to run Apache Sqoop jobs in Azure HDInsight to import and export data between an HDInsight cluster and Azure SQL Database or SQL Server. This article is a continuation of Use Apache Sqoop with Hadoop in HDInsight.

Prerequisites

Sqoop export

From Hive to SQL.

This example exports data from the Hive hivesampletable table to the mobiledata table in SQL. Set the values for the variables below and then execute the command.

$hdinsightClusterName = ""
$httpPassword = ''
$sqlDatabasePassword = ''

# These values only need to be changed if the template was not followed.
$httpUserName = "admin"
$sqlServerLogin = "sqluser"
$sqlServerName = $hdinsightClusterName + "dbserver"
$sqlDatabaseName = $hdinsightClusterName + "db"

$pw = ConvertTo-SecureString -String $httpPassword -AsPlainText -Force
$httpCredential = New-Object System.Management.Automation.PSCredential($httpUserName,$pw)

# Connection string
$connectionString = "jdbc:sqlserver://$sqlServerName.database.windows.net;user=$sqlServerLogin@$sqlServerName;password=$sqlDatabasePassword;database=$sqlDatabaseName"

# start export
New-AzHDInsightSqoopJobDefinition `
    -Command "export --connect $connectionString --table mobiledata --hcatalog-table hivesampletable" `
    | Start-AzHDInsightJob `
        -ClusterName $hdinsightClusterName `
        -HttpCredential $httpCredential

Alternative execution

  1. The code below performs the same export; however, it provides a way to read the output logs. Execute the code to begin the export.

    $sqoopCommand = "export --connect $connectionString --table mobiledata --hcatalog-table hivesampletable"

$sqoopDef = New-AzHDInsightSqoopJobDefinition `
    -Command $sqoopCommand

$sqoopJob = Start-AzHDInsightJob `
                -ClusterName $hdinsightClusterName `
                -HttpCredential $httpCredential `
                -JobDefinition $sqoopDef

  2. The code below displays the output logs. Execute the code below:

    Get-AzHDInsightJobOutput `
    -ClusterName $hdinsightClusterName `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardError

Get-AzHDInsightJobOutput `
    -ClusterName $hdinsightClusterName `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardOutput

If you receive the error message, The specified blob does not exist., try again after a few minutes.

Sqoop import

From SQL to Azure Storage. This example imports data from the mobiledata table in SQL, to the wasb:///tutorials/usesqoop/importeddata directory on HDInsight. The fields in the data are separated by a tab character, and the lines are terminated by a new-line character. This example assumes you've completed the prior example.

$sqoopCommand = "import --connect $connectionString --table mobiledata --target-dir wasb:///tutorials/usesqoop/importeddata --fields-terminated-by '\t' --lines-terminated-by '\n' -m 1"


$sqoopDef = New-AzHDInsightSqoopJobDefinition `
    -Command $sqoopCommand

$sqoopJob = Start-AzHDInsightJob `
                -ClusterName $hdinsightClusterName `
                -HttpCredential $httpCredential `
                -JobDefinition $sqoopDef

Get-AzHDInsightJobOutput `
    -ClusterName $hdinsightClusterName `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardError

Get-AzHDInsightJobOutput `
    -ClusterName $hdinsightClusterName `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardOutput

Additional Sqoop export example

This is a robust example that exports data from /tutorials/usesqoop/data/sample.log from the default storage account, and then imports it to a table called log4jlogs in a SQL Server database. This example isn't dependent on the prior examples.

The following PowerShell script pre-processes the source file and then exports it to table log4jlogs. Replace CLUSTERNAME, CLUSTERPASSWORD, and SQLPASSWORD with the values you used from the prerequisite.

<#------ BEGIN USER INPUT ------#>
$hdinsightClusterName = "CLUSTERNAME"
$httpUserName = "admin"  #default is admin, update as needed
$httpPassword = 'CLUSTERPASSWORD'
$sqlDatabasePassword = 'SQLPASSWORD'
<#------- END USER INPUT -------#>

# Other fixed variable that should be used as is
$sqlServerName = $hdinsightClusterName + "dbserver"
$sqlDatabaseName = $hdinsightClusterName + "db"
$tableName_log4j = "log4jlogs"
$exportDir_log4j = "/tutorials/usesqoop/data"
$sourceBlobName = "example/data/sample.log"
$destBlobName = "tutorials/usesqoop/data/sample.log"
$sqljdbcdriver = "/user/oozie/share/lib/sqoop/mssql-jdbc-7.0.0.jre8.jar"

$cluster = Get-AzHDInsightCluster -ClusterName $hdinsightClusterName
$defaultStorageAccountName = $cluster.DefaultStorageAccount -replace '.blob.core.windows.net'
$defaultStorageContainer = $cluster.DefaultStorageContainer
$resourceGroup = $cluster.ResourceGroup

$sqlServer = Get-AzSqlServer -ResourceGroupName $resourceGroup -ServerName $sqlServerName
$sqlServerLogin = $sqlServer.SqlAdministratorLogin
$sqlServerFQDN = $sqlServer.FullyQualifiedDomainName

#Connect to Azure subscription
Write-Host "`nConnecting to your Azure subscription ..." -ForegroundColor Green
try{Get-AzContext}
catch{Connect-AzAccount}

#pre-process the source file
Write-Host "`nPreprocessing the source file ..." -ForegroundColor Green

# This procedure creates a new file with $destBlobName
# Define the connection string
$defaultStorageAccountKey = (Get-AzStorageAccountKey `
                                -ResourceGroupName $resourceGroup `
                                -Name $defaultStorageAccountName)[0].Value

# Create block blob objects referencing the source and destination blob.
$storageAccount = Get-AzStorageAccount `
    -ResourceGroupName $resourceGroup `
    -Name $defaultStorageAccountName

$storageContainer = ($storageAccount |Get-AzStorageContainer -Name $defaultStorageContainer).CloudBlobContainer

$sourceBlob = $storageContainer.GetBlockBlobReference($sourceBlobName)
$destBlob = $storageContainer.GetBlockBlobReference($destBlobName)

# Define a MemoryStream and a StreamReader for reading from the source file
$stream = New-Object System.IO.MemoryStream
$stream = $sourceBlob.OpenRead()
$sReader = New-Object System.IO.StreamReader($stream)

# Define a MemoryStream and a StreamWriter for writing into the destination file
$memStream = New-Object System.IO.MemoryStream
$writeStream = New-Object System.IO.StreamWriter $memStream

# Pre-process the source blob
$exString = "java.lang.Exception:"
while(-Not $sReader.EndOfStream){
    $line = $sReader.ReadLine()
    $split = $line.Split(" ")

    # remove the "java.lang.Exception" from the first element of the array
    # for example: java.lang.Exception: 2012-02-03 19:11:02 SampleClass8 [WARN] problem finding id 153454612
    if ($split[0] -eq $exString){
        #create a new ArrayList to remove $split[0]
        $newArray = [System.Collections.ArrayList] $split
        $newArray.Remove($exString)

        # update $split and $line
        $split = $newArray
        $line = $newArray -join(" ")
    }

    # remove the lines that has less than 7 elements
    if ($split.count -ge 7){
        write-host $line
        $writeStream.WriteLine($line)
    }
}

# Write to the destination blob
$writeStream.Flush()
$memStream.Seek(0, "Begin")
$destBlob.UploadFromStream($memStream)

#export the log file from the cluster to SQL
Write-Host "Exporting the log file ..." -ForegroundColor Green

$pw = ConvertTo-SecureString -String $httpPassword -AsPlainText -Force
$httpCredential = New-Object System.Management.Automation.PSCredential($httpUserName,$pw)

# Connection string
$connectionString = "jdbc:sqlserver://$sqlServerFQDN;user=$sqlServerLogin@$sqlServerName;password=$sqlDatabasePassword;database=$sqlDatabaseName"

# Submit a Sqoop job
$sqoopDef = New-AzHDInsightSqoopJobDefinition `
    -Command "export --connect $connectionString --table $tableName_log4j --export-dir $exportDir_log4j --input-fields-terminated-by \0x20 -m 1" `
    -Files $sqljdbcdriver

$sqoopJob = Start-AzHDInsightJob `
                -ClusterName $hdinsightClusterName `
                -HttpCredential $httpCredential `
                -JobDefinition $sqoopDef

Wait-AzHDInsightJob `
    -ResourceGroupName $resourceGroup `
    -ClusterName $hdinsightClusterName `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId

Write-Host "Standard Error" -BackgroundColor Green
Get-AzHDInsightJobOutput `
    -ResourceGroupName $resourceGroup `
    -ClusterName $hdinsightClusterName `
    -DefaultStorageAccountName $defaultStorageAccountName `
    -DefaultStorageAccountKey $defaultStorageAccountKey `
    -DefaultContainer $defaultStorageContainer `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardError

Write-Host "Standard Output" -BackgroundColor Green
Get-AzHDInsightJobOutput `
    -ResourceGroupName $resourceGroupName `
    -ClusterName $hdinsightClusterName `
    -DefaultStorageAccountName $defaultStorageAccountName `
    -DefaultStorageAccountKey $defaultStorageAccountKey `
    -DefaultContainer $defaultStorageContainer `
    -HttpCredential $httpCredential `
    -JobId $sqoopJob.JobId `
    -DisplayOutputType StandardOutput

Limitations

Linux-based HDInsight presents the following limitations:

  • Bulk export: The Sqoop connector that's used to export data to SQL doesn't currently support bulk inserts.

  • Batching: By using the -batch switch when it performs inserts, Sqoop performs multiple inserts instead of batching the insert operations.

Next steps

Now you've learned how to use Sqoop. To learn more, see: