不過有時候我們在創建SQLContext實例的時候遇到類似下面的
java.lang.RuntimeException: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:522) at org.apache.spark.sql.hive.client.ClientWrapper.<init>(ClientWrapper.scala:171) at org.apache.spark.sql.hive.HiveContext.executionHive$lzycompute(HiveContext.scala:162) at org.apache.spark.sql.hive.HiveContext.executionHive(HiveContext.scala:160) at org.apache.spark.sql.hive.HiveContext.setConf(HiveContext.scala:391) at org.apache.spark.sql.SQLContext$$anonfun$5.apply(SQLContext.scala:235) at org.apache.spark.sql.SQLContext$$anonfun$5.apply(SQLContext.scala:234) at scala.collection.Iterator$class.foreach(Iterator.scala:727) at scala.collection.AbstractIterator.foreach(Iterator.scala:1157) at scala.collection.IterableLike$class.foreach(IterableLike.scala:72) at scala.collection.AbstractIterable.foreach(Iterable.scala:54) at org.apache.spark.sql.SQLContext.<init>(SQLContext.scala:234) at org.apache.spark.sql.hive.HiveContext.<init>(HiveContext.scala:72) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at org.apache.spark.repl.SparkILoop.createSQLContext(SparkILoop.scala:1028) at $iwC$$iwC.<init>(<console>:9) at $iwC.<init>(<console>:18) at <init>(<console>:20) at .<init>(<console>:24) at .<clinit>(<console>) at .<init>(<console>:7) at .<clinit>(<console>) at $print(<console>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.spark.repl.SparkIMain$ReadEvalPrint.call(SparkIMain.scala:1065) at org.apache.spark.repl.SparkIMain$Request.loadAndRun(SparkIMain.scala:1340) at org.apache.spark.repl.SparkIMain.loadAndRunReq$1(SparkIMain.scala:840) at org.apache.spark.repl.SparkIMain.interpret(SparkIMain.scala:871) at org.apache.spark.repl.SparkIMain.interpret(SparkIMain.scala:819) at org.apache.spark.repl.SparkILoop.reallyInterpret$1(SparkILoop.scala:857) at org.apache.spark.repl.SparkILoop.interpretStartingWith(SparkILoop.scala:902) at org.apache.spark.repl.SparkILoop.command(SparkILoop.scala:814) at org.apache.spark.repl.SparkILoopInit$$anonfun$initializeSpark$1.apply(SparkILoopInit.scala:132) at org.apache.spark.repl.SparkILoopInit$$anonfun$initializeSpark$1.apply(SparkILoopInit.scala:124) at org.apache.spark.repl.SparkIMain.beQuietDuring(SparkIMain.scala:324) at org.apache.spark.repl.SparkILoopInit$class.initializeSpark(SparkILoopInit.scala:124) at org.apache.spark.repl.SparkILoop.initializeSpark(SparkILoop.scala:64) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1$$anonfun$apply$mcZ$sp$5.apply$mcV$sp(SparkILoop.scala:974) at org.apache.spark.repl.SparkILoopInit$class.runThunks(SparkILoopInit.scala:159) at org.apache.spark.repl.SparkILoop.runThunks(SparkILoop.scala:64) at org.apache.spark.repl.SparkILoopInit$class.postInitialization(SparkILoopInit.scala:108) at org.apache.spark.repl.SparkILoop.postInitialization(SparkILoop.scala:64) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply$mcZ$sp(SparkILoop.scala:991) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply(SparkILoop.scala:945) at org.apache.spark.repl.SparkILoop$$anonfun$org$apache$spark$repl$SparkILoop$$process$1.apply(SparkILoop.scala:945) at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135) at org.apache.spark.repl.SparkILoop.org$apache$spark$repl$SparkILoop$$process(SparkILoop.scala:945) at org.apache.spark.repl.SparkILoop.process(SparkILoop.scala:1059) at org.apache.spark.repl.Main$.main(Main.scala:31) at org.apache.spark.repl.Main.main(Main.scala) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:674) at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:180) at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:205) at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:120) at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala) Caused by: java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient at org.apache.hadoop.hive.metastore.MetaStoreUtils.newInstance(MetaStoreUtils.java:1523) at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.<init>(RetryingMetaStoreClient.java:86) at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.getProxy(RetryingMetaStoreClient.java:132) at org.apache.hadoop.hive.metastore.RetryingMetaStoreClient.getProxy(RetryingMetaStoreClient.java:104) at org.apache.hadoop.hive.ql.metadata.Hive.createMetaStoreClient(Hive.java:3005) at org.apache.hadoop.hive.ql.metadata.Hive.getMSC(Hive.java:3024) at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:503) ... 64 more Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526) at org.apache.hadoop.hive.metastore.MetaStoreUtils.newInstance(MetaStoreUtils.java:1521) ... 70 more Caused by: MetaException(message:Version information not found in metastore. ) at org.apache.hadoop.hive.metastore.ObjectStore.checkSchema(ObjectStore.java:6664) at org.apache.hadoop.hive.metastore.ObjectStore.verifySchema(ObjectStore.java:6645) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.hadoop.hive.metastore.RawStoreProxy.invoke(RawStoreProxy.java:114) at com.sun.proxy.$Proxy14.verifySchema(Unknown Source) at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.getMS(HiveMetaStore.java:572) at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.createDefaultDB(HiveMetaStore.java:620) at org.apache.hadoop.hive.metastore.HiveMetaStore$HMSHandler.init(HiveMetaStore.java:461) at org.apache.hadoop.hive.metastore.RetryingHMSHandler.<init>(RetryingHMSHandler.java:66) at org.apache.hadoop.hive.metastore.RetryingHMSHandler.getProxy(RetryingHMSHandler.java:72) at org.apache.hadoop.hive.metastore.HiveMetaStore.newRetryingHMSHandler(HiveMetaStore.java:5762) at org.apache.hadoop.hive.metastore.HiveMetaStoreClient.<init>(HiveMetaStoreClient.java:199) at org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient.<init>(SessionHiveMetaStoreClient.java:74) ... 75 more
這是因為在創建
SQLContext實例的時候，要求spark編譯的
Hive版本和HiveMetaStore里面記錄的Hive版本一致，我們可以通過配置hive.metastore.schema.verification參數來取消這種驗證，這個參數的默認值是true，我們可以取消驗證，配置如下：
<property> <name>hive.metastore.schema.verification</name> <value>false</value> <description> Enforce metastore schema version consistency. True: Verify that version information stored in metastore matches with one from Hive jars. Also disable automatic schema migration attempt. Users are required to manully migrate schema after Hive upgrade which ensures proper metastore schema migration. (Default) False: Warn if the version information stored in metastore doesn't match with one from in Hive jars. </description> </property>
然后我們再啟動Spark，這時候就可以創建SQLContext實例了。