SparkSQL访问Hive遇到的问题及解决方法

需要先将hadoop的core-site.xml，hive的hive-site.xml拷贝到project中

测试代码

def main(args: Array[String]): Unit = {
    val spark: SparkSession = SparkSession
      .builder()
      .appName("TopNApp")
      .master("local[2]")
      .enableHiveSupport()
      .getOrCreate()
	val userClickDF = spark.table("user_click")
    userClickDF.show(10)
}

报错

Exception in thread "main" java.lang.IllegalArgumentException: Unable to instantiate SparkSession with Hive support because Hive classes are not found.
	at org.apache.spark.sql.SparkSession$Builder.enableHiveSupport(SparkSession.scala:869)
	at homework0522.OverwriteTopN$.main(OverwriteTopN.scala:12)
	at homework0522.OverwriteTopN.main(OverwriteTopN.scala)

查看源码

"SparkSession.scala"
    /**
     * Enables Hive support, including connectivity to a persistent Hive metastore, support for
     * Hive serdes, and Hive user-defined functions.
     *
     * @since 2.0.0
     */
    
    def enableHiveSupport(): Builder = synchronized {
      "在这里进行if判断的时候找不到hive class"
      if (hiveClassesArePresent) {
        config(CATALOG_IMPLEMENTATION.key, "hive")
      } else {
        throw new IllegalArgumentException(
          "Unable to instantiate SparkSession with Hive support because " +
            "Hive classes are not found.")
      }
    }
    
  /**
   * @return true if Hive classes can be loaded, otherwise false.
   */
  private[spark] def hiveClassesArePresent: Boolean = {
    try {
      "这里通过Class.forName去找下面的两个类，第一个类的时候就找不到了"
      Utils.classForName(HIVE_SESSION_STATE_BUILDER_CLASS_NAME)
      Utils.classForName("org.apache.hadoop.hive.conf.HiveConf")
      true
    } catch {
      case _: ClassNotFoundException | _: NoClassDefFoundError => false
    }
  }

   "发现找不到HiveSessionStateBuilder"
   private val HIVE_SESSION_STATE_BUILDER_CLASS_NAME =
    "org.apache.spark.sql.hive.HiveSessionStateBuilder"

解决方法

将$HIVE_HOME/lib下的spark-hive_2.11-2.4.2.jar与spark-hive-thriftserver_2.11-2.4.2.jar添加到project中

继续报错

Exception in thread "main" java.lang.NoSuchFieldError: METASTORE_CLIENT_SOCKET_LIFETIME
	at org.apache.spark.sql.hive.HiveUtils$.formatTimeVarsForHiveClient(HiveUtils.scala:194)
	at org.apache.spark.sql.hive.HiveUtils$.newClientForMetadata(HiveUtils.scala:285)
	at org.apache.spark.sql.hive.HiveExternalCatalog.client$lzycompute(HiveExternalCatalog.scala:66)

查看源码

"HiveUtils.scala"
  /**
   * Change time configurations needed to create a [[HiveClient]] into unified [[Long]] format.
   */
  private[hive] def formatTimeVarsForHiveClient(hadoopConf: Configuration): Map[String, String] = {
    // Hive 0.14.0 introduces timeout operations in HiveConf, and changes default values of a bunch
    // of time `ConfVar`s by adding time suffixes (`s`, `ms`, and `d` etc.).  This breaks backwards-
    // compatibility when users are trying to connecting to a Hive metastore of lower version,
    // because these options are expected to be integral values in lower versions of Hive.
    //
    // Here we enumerate all time `ConfVar`s and convert their values to numeric strings according
    // to their output time units.
    Seq(
      ConfVars.METASTORE_CLIENT_CONNECT_RETRY_DELAY -> TimeUnit.SECONDS,
      ConfVars.METASTORE_CLIENT_SOCKET_TIMEOUT -> TimeUnit.SECONDS,
      "在这里读不到值"
      ConfVars.METASTORE_CLIENT_SOCKET_LIFETIME -> TimeUnit.SECONDS,
      ...
    ).map { case (confVar, unit) =>
      confVar.varname -> HiveConf.getTimeVar(hadoopConf, confVar, unit).toString
    }.toMap
  }

进入ConfVars

"HiveConf.java"
public static enum ConfVars {
        SCRIPTWRAPPER("hive.exec.script.wrapper", (Object)null, ""),
        PLAN("hive.exec.plan", "", ""),
        ...
}

发现ConfVars中定义的变量并没有METASTORE_CLIENT_SOCKET_LIFETIME，而HiveConf.java来自于hive-exec-1.1.0-cdh5.7.0.jar，即证明hive1.1.0中并没有假如该参数。

解决方法

将hive依赖换为1.2.1

<properties>
  ...
  
  <hive.version>1.2.1hive.version>
properties>

...
<dependency>
  <groupId>org.apache.hivegroupId>
  <artifactId>hive-execartifactId>
  <version>${hive.version}version>
dependency>

继续报错

Exception in thread "main" org.apache.spark.sql.AnalysisException: java.lang.RuntimeException: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient;
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient
Caused by: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient
Caused by: java.lang.reflect.InvocationTargetException
Caused by: MetaException(message:Could not connect to meta store using any of the URIs provided. Most recent failure: org.apache.thrift.transport.TTransportException: java.net.ConnectException: Connection refused: connect
Caused by: java.net.ConnectException: Connection refused: connect

解决方法

这是因为远端没有启动hive造成的，启动hive时需要配置metastore。

$HIVE_HOME/bin/hive --service metastore &