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Run Apache Hive queries using HDInsight .NET SDK

  • Artikkeli

Learn how to submit Apache Hive queries using HDInsight .NET SDK. You write a C# program to submit a Hive query for listing Hive tables, and display the results.

Note

The steps in this article must be performed from a Windows client. For information on using a Linux, OS X, or Unix client to work with Hive, use the tab selector shown on the top of the article.

Prerequisites

Before you begin this article, you must have the following items:

  • An Apache Hadoop cluster in HDInsight. See Get started using Linux-based Hadoop in HDInsight.

    Important

    As of September 15, 2017, the HDInsight .NET SDK only supports returning Hive query results from Azure Storage accounts. If you use this example with an HDInsight cluster that uses Azure Data Lake Storage as primary storage, you cannot retrieve search results using the .NET SDK.

  • Visual Studio 2013 and beyond. At least workload .NET desktop development should be installed.

Run a Hive Query

The HDInsight .NET SDK provides .NET client libraries, which makes it easier to work with HDInsight clusters from .NET.

  1. Create a C# console application in Visual Studio.

  2. From the Nuget Package Manager Console, run the following command:

    Install-Package Microsoft.Azure.Management.HDInsight.Job

  3. Edit the code below to initialize the values for variables: ExistingClusterName, ExistingClusterUsername, ExistingClusterPassword,DefaultStorageAccountName,DefaultStorageAccountKey,DefaultStorageContainerName. Then use the revised code as the entire contents of Program.cs in Visual Studio.

    using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading;
using Microsoft.Azure.Management.HDInsight.Job;
using Microsoft.Azure.Management.HDInsight.Job.Models;
using Hyak.Common;

namespace SubmitHDInsightJobDotNet
{
    class Program
    {
        private static HDInsightJobManagementClient _hdiJobManagementClient;

        private const string ExistingClusterName = "<Your HDInsight Cluster Name>";
        private const string ExistingClusterUsername = "<Cluster Username>";
        private const string ExistingClusterPassword = "<Cluster User Password>";

        // Only Azure Storage accounts are supported by the SDK
        private const string DefaultStorageAccountName = "<Default Storage Account Name>";
        private const string DefaultStorageAccountKey = "<Default Storage Account Key>";
        private const string DefaultStorageContainerName = "<Default Blob Container Name>";

        private const string ExistingClusterUri = ExistingClusterName + ".azurehdinsight.net";

        static void Main(string[] args)
        {
            System.Console.WriteLine("The application is running ...");

            var clusterCredentials = new BasicAuthenticationCloudCredentials { Username = ExistingClusterUsername, Password = ExistingClusterPassword };
            _hdiJobManagementClient = new HDInsightJobManagementClient(ExistingClusterUri, clusterCredentials);

            SubmitHiveJob();

            System.Console.WriteLine("Press ENTER to continue ...");
            System.Console.ReadLine();
        }

        private static void SubmitHiveJob()
        {
            Dictionary<string, string> defines = new Dictionary<string, string> { { "hive.execution.engine", "tez" }, { "hive.exec.reducers.max", "1" } };
            List<string> args = new List<string> { { "argA" }, { "argB" } };
            var parameters = new HiveJobSubmissionParameters
            {
                Query = "SHOW TABLES",
                Defines = defines,
                Arguments = args
            };

            System.Console.WriteLine("Submitting the Hive job to the cluster...");
            var jobResponse = _hdiJobManagementClient.JobManagement.SubmitHiveJob(parameters);
            var jobId = jobResponse.JobSubmissionJsonResponse.Id;
            System.Console.WriteLine("Response status code is " + jobResponse.StatusCode);
            System.Console.WriteLine("JobId is " + jobId);

            System.Console.WriteLine("Waiting for the job completion ...");

            // Wait for job completion
            var jobDetail = _hdiJobManagementClient.JobManagement.GetJob(jobId).JobDetail;
            while (!jobDetail.Status.JobComplete)
            {
                Thread.Sleep(1000);
                jobDetail = _hdiJobManagementClient.JobManagement.GetJob(jobId).JobDetail;
            }

            // Get job output
            var storageAccess = new AzureStorageAccess(DefaultStorageAccountName, DefaultStorageAccountKey,
                DefaultStorageContainerName);
            var output = (jobDetail.ExitValue == 0)
                ? _hdiJobManagementClient.JobManagement.GetJobOutput(jobId, storageAccess) // fetch stdout output in case of success
                : _hdiJobManagementClient.JobManagement.GetJobErrorLogs(jobId, storageAccess); // fetch stderr output in case of failure

            System.Console.WriteLine("Job output is: ");

            using (var reader = new StreamReader(output, Encoding.UTF8))
            {
                string value = reader.ReadToEnd();
                System.Console.WriteLine(value);
            }
        }
    }
}

  4. Press F5 to run the application.

The output of the application should be similar to:

HDInsight Hadoop Hive job output.

Next steps

In this article, you learned how to submit Apache Hive queries using HDInsight .NET SDK. To learn more, see the following articles: