以下是确切的异常:
com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [varchar <-> java.math.BigDecimal]
我正在使用以下软件版本:Spark 1.5、Datastax-cassandra 3.2.1、CDH 5.5.1
我正在尝试执行一个使用Java API的Spark程序,它基本上从HDFS读取数据(CSV文件)并将其加载到Cassandra表中。我正在使用spark-cassandra-connector。最初,我遇到了许多有关Google's guava库冲突的问题,但通过阴影化guava库并构建具有所有依赖项的快照jar,我成功解决了这些问题。
然而,对于某些文件,我能够加载数据,但对于某些文件,我会收到Codec异常。当我研究这个问题时,我得到了以下与此问题相关的线程。
https://groups.google.com/a/lists.datastax.com/forum/#!topic/java-driver-user/yZyaOQ-wazk
https://groups.google.com/a/lists.datastax.com/forum/#!topic/java-driver-user/yZyaOQ-wazk
通过阅读这些讨论,我了解到可能是我使用的cassandra-driver版本不正确,或者与guava库相关的类路径问题仍然存在,因为Cassandra 3.0及更高版本使用guava 16.0.1,并且上述讨论中说可能在类路径中存在较低版本的guava。
以下是pom.xml文件
<dependencies>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.datastax.spark</groupId>
<artifactId>spark-cassandra-connector-java_2.10</artifactId>
<version>1.5.0-M3</version>
</dependency>
<dependency>
<groupId>org.apache.cassandra</groupId>
<artifactId>cassandra-clientutil</artifactId>
<version>3.2.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.3</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<filters>
<filter>
<artifact>*:*</artifact>
<excludes>
<exclude>META-INF/*.SF</exclude>
<exclude>META-INF/*.DSA</exclude>
<exclude>META-INF/*.RSA</exclude>
</excludes>
</filter>
</filters>
<relocations>
<relocation>
<pattern>com.google</pattern>
<shadedPattern>com.pointcross.shaded.google</shadedPattern>
</relocation>
</relocations>
<minimizeJar>false</minimizeJar>
<shadedArtifactAttached>true</shadedArtifactAttached>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
这些是使用上述pom下载的依赖项。
spark-core_2.10-1.5.0.jar
spark-cassandra-connector- java_2.10-1.5.0-M3.jar
spark-cassandra-connector_2.10-1.5.0-M3.jar
spark-repl_2.10-1.5.1.jar
spark-bagel_2.10-1.5.1.jar
spark-mllib_2.10-1.5.1.jar
spark-streaming_2.10-1.5.1.jar
spark-graphx_2.10-1.5.1.jar
guava-16.0.1.jar
cassandra-clientutil-3.2.1.jar
cassandra-driver-core-3.0.0-alpha4.jar
这是一些我的快照 jar 包的主要依赖项。为什么出现了 CodecNotFoundException?是因为类路径(guava)吗?还是因为 cassandra-driver(cassandra-driver-core-3.0.0-alpha4.jar 用于 datastax cassandra 3.2.1),或者是因为代码本身?
另一个问题是,我正在向数据类型为 timestamp 的列中插入所有日期。
此外,当我执行 spark-submit 时,日志中显示了类路径。在 hadoop 库下有其他 guava 版本,它们会导致问题吗?
在进行 spark-submit 时,我们如何指定特定于用户的类路径?这有帮助吗?
很高兴听到对这些问题的观点。 谢谢
以下是堆栈跟踪。
com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [timestamp <-> java.lang.String]
at com.datastax.driver.core.CodecRegistry.notFound(CodecRegistry.java:689)
at com.datastax.driver.core.CodecRegistry.createCodec(CodecRegistry.java:550)
at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:530)
at com.datastax.driver.core.CodecRegistry.codecFor(CodecRegistry.java:485)
at com.datastax.driver.core.AbstractGettableByIndexData.codecFor(AbstractGettableByIndexData.java:85)
at com.datastax.driver.core.BoundStatement.bind(BoundStatement.java:198)
at com.datastax.driver.core.DefaultPreparedStatement.bind(DefaultPreparedStatement.java:126)
at com.cassandra.test.LoadDataToCassandra$1.call(LoadDataToCassandra.java:223)
at com.cassandra.test.LoadDataToCassandra$1.call(LoadDataToCassandra.java:1)
at org.apache.spark.api.java.JavaPairRDD$$anonfun$toScalaFunction$1.apply(JavaPairRDD.scala:1027)
at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
at org.apache.spark.util.Utils$.getIteratorSize(Utils.scala:1555)
at org.apache.spark.rdd.RDD$$anonfun$count$1.apply(RDD.scala:1121)
at org.apache.spark.rdd.RDD$$anonfun$count$1.apply(RDD.scala:1121)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1850)
at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1850)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
at org.apache.spark.scheduler.Task.run(Task.scala:88)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
我也得到了
com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [Math.BigDecimal <-> java.lang.String]