我已经使用 Hortonworks Ambari 安装了 HDFS、Yarn 和 Spark。我编写了简单的程序来读取/读取 HDFS、Map-Reduce wordcount，一切正常。
然后我尝试测试 Spark。我从官方 Spark 示例中复制了字数统计程序:
public final class JavaWordCount {
private static final Pattern SPACE = Pattern.compile(" ");
public static void main(String[] args) throws Exception {
if (args.length < 1) {
System.err.println("Usage: JavaWordCount <file>");
System.exit(1);
}
SparkSession spark = SparkSession
.builder()
.appName("JavaWordCount")
.getOrCreate();
JavaRDD<String> lines = spark.read().textFile(args[0]).javaRDD();
JavaRDD<String> words = lines.flatMap(s -> Arrays.asList(SPACE.split(s)).iterator());
JavaPairRDD<String, Integer> ones = words.mapToPair(s -> new Tuple2<>(s, 1));
JavaPairRDD<String, Integer> counts = ones.reduceByKey((i1, i2) -> i1 + i2);
List<Tuple2<String, Integer>> output = counts.collect();
for (Tuple2<?,?> tuple : output) {
System.out.println(tuple._1() + ": " + tuple._2());
}
spark.stop();
}
}
我在 hdfs://server:8020/user/root/input.txt 中放置了一个内容为“Hello World”的 input.txt 文件。
然后我使用以下命令运行这个程序，
java -cp "all necessary jars provided by Ambari, I believe the version should match" JavaWordCount hdfs://server:8020/user/root/input.txt
然后有一个非常奇怪的异常，即使我在谷歌上搜索我也找不到任何类似的匹配项。
异常发生在第27行
JavaRDD<String> lines = spark.read().textFile(args[0]).javaRDD();
奇怪的是我在搜索引擎上找不到任何完全匹配的异常。
是否有任何提示可供我检查和研究以使其正常工作？谢谢。异常很长，最后列出来。
java.lang.AssertionError: assertion failed: unsafe symbol Unstable (child of package InterfaceStability) in runtime reflection universe
at scala.reflect.internal.Symbols$Symbol.<init>(Symbols.scala:184)
at scala.reflect.internal.Symbols$TypeSymbol.<init>(Symbols.scala:3009)
at scala.reflect.internal.Symbols$ClassSymbol.<init>(Symbols.scala:3201)
at scala.reflect.internal.Symbols$StubClassSymbol.<init>(Symbols.scala:3496)
at scala.reflect.internal.Symbols$Symbol.newStubSymbol(Symbols.scala:498)
at scala.reflect.internal.pickling.UnPickler$Scan.readExtSymbol$1(UnPickler.scala:258)
at scala.reflect.internal.pickling.UnPickler$Scan.readSymbol(UnPickler.scala:284)
at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolRef(UnPickler.scala:649)
at scala.reflect.internal.pickling.UnPickler$Scan.readType(UnPickler.scala:417)
at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:658)
at scala.reflect.internal.pickling.UnPickler$Scan$$anonfun$readTypeRef$1.apply(UnPickler.scala:658)
at scala.reflect.internal.pickling.UnPickler$Scan.at(UnPickler.scala:179)
at scala.reflect.internal.pickling.UnPickler$Scan.readTypeRef(UnPickler.scala:658)
at scala.reflect.internal.pickling.UnPickler$Scan.readAnnotationInfo(UnPickler.scala:492)
at scala.reflect.internal.pickling.UnPickler$Scan.readSymbolAnnotation(UnPickler.scala:515)
at scala.reflect.internal.pickling.UnPickler$Scan.run(UnPickler.scala:97)
at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:38)
at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:619)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply$mcV$sp(SymbolLoaders.scala:28)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply(SymbolLoaders.scala:25)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply(SymbolLoaders.scala:25)
at scala.reflect.internal.SymbolTable.slowButSafeEnteringPhaseNotLaterThan(SymbolTable.scala:263)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:25)
at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1514)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.scala$reflect$runtime$SynchronizedSymbols$SynchronizedSymbol$$super$info(SynchronizedSymbols.scala:189)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.Gil$class.gilSynchronized(Gil.scala:19)
at scala.reflect.runtime.JavaUniverse.gilSynchronized(JavaUniverse.scala:16)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:123)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:189)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.info(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.info(SynchronizedSymbols.scala:189)
at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:286)
at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:341)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply$mcV$sp(SymbolLoaders.scala:74)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply(SymbolLoaders.scala:71)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply(SymbolLoaders.scala:71)
at scala.reflect.internal.SymbolTable.slowButSafeEnteringPhaseNotLaterThan(SymbolTable.scala:263)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:71)
at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1514)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.scala$reflect$runtime$SynchronizedSymbols$SynchronizedSymbol$$super$info(SynchronizedSymbols.scala:174)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.Gil$class.gilSynchronized(Gil.scala:19)
at scala.reflect.runtime.JavaUniverse.gilSynchronized(JavaUniverse.scala:16)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:123)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:174)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.info(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.info(SynchronizedSymbols.scala:174)
at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2194)
at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2199)
at scala.reflect.internal.tpe.FindMembers$FindMemberBase.<init>(FindMembers.scala:17)
at scala.reflect.internal.tpe.FindMembers$FindMember.<init>(FindMembers.scala:219)
at scala.reflect.internal.Types$Type.scala$reflect$internal$Types$Type$$findMemberInternal$1(Types.scala:1014)
at scala.reflect.internal.Types$Type.findMember(Types.scala:1016)
at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:631)
at scala.reflect.internal.Types$Type.member(Types.scala:600)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:48)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:66)
at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:77)
at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161)
at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:22)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1$$typecreator46$1.apply(ScalaReflection.scala:654)
at scala.reflect.api.TypeTags$WeakTypeTagImpl.tpe$lzycompute(TypeTags.scala:232)
at scala.reflect.api.TypeTags$WeakTypeTagImpl.tpe(TypeTags.scala:232)
at org.apache.spark.sql.catalyst.ScalaReflection$class.localTypeOf(ScalaReflection.scala:839)
at org.apache.spark.sql.catalyst.ScalaReflection$.localTypeOf(ScalaReflection.scala:39)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply$mcZ$sp(ScalaReflection.scala:654)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply(ScalaReflection.scala:653)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply(ScalaReflection.scala:653)
at scala.reflect.internal.tpe.TypeConstraints$UndoLog.undo(TypeConstraints.scala:56)
at org.apache.spark.sql.catalyst.ScalaReflection$class.cleanUpReflectionObjects(ScalaReflection.scala:824)
at org.apache.spark.sql.catalyst.ScalaReflection$.cleanUpReflectionObjects(ScalaReflection.scala:39)
at org.apache.spark.sql.catalyst.ScalaReflection$.optionOfProductType(ScalaReflection.scala:652)
at org.apache.spark.sql.catalyst.encoders.ExpressionEncoder$.apply(ExpressionEncoder.scala:51)
at org.apache.spark.sql.Encoders$.STRING(Encoders.scala:96)
at org.apache.spark.sql.SQLImplicits.newStringEncoder(SQLImplicits.scala:73)
at org.apache.spark.sql.DataFrameReader.textFile(DataFrameReader.scala:732)
at org.apache.spark.sql.DataFrameReader.textFile(DataFrameReader.scala:702)
at JavaWordCount .main(JavaWordCount .java:27)
Exception in thread "main" java.lang.RuntimeException: error reading Scala signature of org.apache.spark.sql.package: assertion failed: unsafe symbol Unstable (child of package InterfaceStability) in runtime reflection universe
at scala.reflect.internal.pickling.UnPickler.unpickle(UnPickler.scala:46)
at scala.reflect.runtime.JavaMirrors$JavaMirror.unpickleClass(JavaMirrors.scala:619)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply$mcV$sp(SymbolLoaders.scala:28)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply(SymbolLoaders.scala:25)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter$$anonfun$complete$1.apply(SymbolLoaders.scala:25)
at scala.reflect.internal.SymbolTable.slowButSafeEnteringPhaseNotLaterThan(SymbolTable.scala:263)
at scala.reflect.runtime.SymbolLoaders$TopClassCompleter.complete(SymbolLoaders.scala:25)
at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1514)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.scala$reflect$runtime$SynchronizedSymbols$SynchronizedSymbol$$super$info(SynchronizedSymbols.scala:189)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.Gil$class.gilSynchronized(Gil.scala:19)
at scala.reflect.runtime.JavaUniverse.gilSynchronized(JavaUniverse.scala:16)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:123)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:189)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.info(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$10.info(SynchronizedSymbols.scala:189)
at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:286)
at scala.reflect.internal.SymbolTable.openPackageModule(SymbolTable.scala:341)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply$mcV$sp(SymbolLoaders.scala:74)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply(SymbolLoaders.scala:71)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType$$anonfun$complete$2.apply(SymbolLoaders.scala:71)
at scala.reflect.internal.SymbolTable.slowButSafeEnteringPhaseNotLaterThan(SymbolTable.scala:263)
at scala.reflect.runtime.SymbolLoaders$LazyPackageType.complete(SymbolLoaders.scala:71)
at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1514)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.scala$reflect$runtime$SynchronizedSymbols$SynchronizedSymbol$$super$info(SynchronizedSymbols.scala:174)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anonfun$info$1.apply(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.Gil$class.gilSynchronized(Gil.scala:19)
at scala.reflect.runtime.JavaUniverse.gilSynchronized(JavaUniverse.scala:16)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:123)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.gilSynchronizedIfNotThreadsafe(SynchronizedSymbols.scala:174)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$class.info(SynchronizedSymbols.scala:127)
at scala.reflect.runtime.SynchronizedSymbols$SynchronizedSymbol$$anon$1.info(SynchronizedSymbols.scala:174)
at scala.reflect.internal.Types$TypeRef.thisInfo(Types.scala:2194)
at scala.reflect.internal.Types$TypeRef.baseClasses(Types.scala:2199)
at scala.reflect.internal.tpe.FindMembers$FindMemberBase.<init>(FindMembers.scala:17)
at scala.reflect.internal.tpe.FindMembers$FindMember.<init>(FindMembers.scala:219)
at scala.reflect.internal.Types$Type.scala$reflect$internal$Types$Type$$findMemberInternal$1(Types.scala:1014)
at scala.reflect.internal.Types$Type.findMember(Types.scala:1016)
at scala.reflect.internal.Types$Type.memberBasedOnName(Types.scala:631)
at scala.reflect.internal.Types$Type.member(Types.scala:600)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:48)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:66)
at scala.reflect.internal.Mirrors$RootsBase.staticModuleOrClass(Mirrors.scala:77)
at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:161)
at scala.reflect.internal.Mirrors$RootsBase.staticModule(Mirrors.scala:22)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1$$typecreator46$1.apply(ScalaReflection.scala:654)
at scala.reflect.api.TypeTags$WeakTypeTagImpl.tpe$lzycompute(TypeTags.scala:232)
at scala.reflect.api.TypeTags$WeakTypeTagImpl.tpe(TypeTags.scala:232)
at org.apache.spark.sql.catalyst.ScalaReflection$class.localTypeOf(ScalaReflection.scala:839)
at org.apache.spark.sql.catalyst.ScalaReflection$.localTypeOf(ScalaReflection.scala:39)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply$mcZ$sp(ScalaReflection.scala:654)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply(ScalaReflection.scala:653)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$optionOfProductType$1.apply(ScalaReflection.scala:653)
at scala.reflect.internal.tpe.TypeConstraints$UndoLog.undo(TypeConstraints.scala:56)
at org.apache.spark.sql.catalyst.ScalaReflection$class.cleanUpReflectionObjects(ScalaReflection.scala:824)
at org.apache.spark.sql.catalyst.ScalaReflection$.cleanUpReflectionObjects(ScalaReflection.scala:39)
at org.apache.spark.sql.catalyst.ScalaReflection$.optionOfProductType(ScalaReflection.scala:652)
at org.apache.spark.sql.catalyst.encoders.ExpressionEncoder$.apply(ExpressionEncoder.scala:51)
at org.apache.spark.sql.Encoders$.STRING(Encoders.scala:96)
at org.apache.spark.sql.SQLImplicits.newStringEncoder(SQLImplicits.scala:73)
at org.apache.spark.sql.DataFrameReader.textFile(DataFrameReader.scala:732)
at org.apache.spark.sql.DataFrameReader.textFile(DataFrameReader.scala:702)
at JavaWordCount .main(JavaWordCount .java:27)
最佳答案
尝试使用spark-submit脚本提交spark作业，不能直接使用java命令，虽然spark-submit也使用java命令。
关于java - Spark wordcount 断言失败 : unsafe symbol Unstable，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53274376/