Eseguire processi Apache Sqoop con Azure PowerShell in HDInsight

  • Articolo

Informazioni su come usare Azure PowerShell per eseguire processi Apache Sqoop in Azure HDInsight per importare ed esportare dati tra un cluster HDInsight e Azure SQL Database o SQL Server. Questo articolo riprende l'articolo Usare Apache Sqoop con Hadoop in HDInsight.

Prerequisiti

Esportazione con Sqoop

Da Hive a SQL.

In questo esempio vengono esportati dati dalla tabella Hive hivesampletable alla mobiledata tabella in SQL. Impostare i valori per le variabili seguenti, quindi eseguire il comando.

$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

Esecuzione alternativa

  1. Il codice seguente esegue la stessa esportazione, ma fornisce anche un modo per leggere i log di output. Eseguire il codice per avviare l'esportazione.

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

$sqoopDef = New-AzHDInsightSqoopJobDefinition `
    -Command $sqoopCommand

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

  2. Il codice riportato di seguito consente di visualizzare i log di output. Eseguire il codice seguente:

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

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

Se viene visualizzato il messaggio di errore The specified blob does not exist., attendere qualche minuto e riprovare.

Importazione con Sqoop

Da SQL ad Archiviazione di Azure. In questo esempio vengono importati dati dalla mobiledata tabella in SQL alla wasb:///tutorials/usesqoop/importeddata directory in HDInsight. I campi nei dati sono separati da un carattere di tabulazione e le righe terminano con un carattere di nuova riga. Questo esempio presuppone che l'esempio precedente sia stato completato.

$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

Altro esempio di esportazione con Sqoop

Si tratta di un esempio affidabile di esportazione dei dati da /tutorials/usesqoop/data/sample.log dall'account di archiviazione predefinito e quindi di importazione in una tabella denominata log4jlogs in un database SQL Server. Questo esempio non dipende dagli esempi precedenti.

Lo script di PowerShell seguente elabora il file di origine e quindi lo esporta nella tabella log4jlogs. Sostituire CLUSTERNAME, CLUSTERPASSWORDe SQLPASSWORD con i valori usati dal prerequisito.

<#------ 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

Limitazioni

HDInsight basato su Linux prevede le limitazioni seguenti:

  • Esportazione bulk: il connettore Sqoop usato per esportare i dati in SQL non supporta attualmente gli inserimenti bulk.

  • Invio in batch: usando l'opzione -batch durante gli inserimenti, Sqoop esegue più inserimenti invece di inviare in batch le operazioni di inserimento.

Passaggi successivi

In questa esercitazione si è appreso come usare Sqoop. Per altre informazioni, vedere: