Datastax Cassandra Driver抛出CodecNotFoundException

Question

确切的例外情况如下

com.datastax.driver.core.exceptions.CodecNotFoundException:找不到请求的操作的编解码器:[varchar < - > java.math.BigDecimal]

这些是我使用Spark 1.5 Datastax-cassandra 3.2.1 CDH 5.5.1的软件版本

我试图执行的代码是使用java api的Spark程序,它基本上从hdfs读取数据(csv)并将其加载到cassandra表中.我正在使用spark-cassandra-connector.最初我有很多关于google s guava库冲突的问题,我可以通过对guava库进行着色并构建一个包含所有依赖项的快照jar来解决这个问题.

但是我能够为某些文件加载​​数据但是对于某些文件我得到了Codec异常.当我研究这个问题时,我在同一个问题上得到了以下线程.

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

经过这些讨论之后,我理解的是它是我正在使用的cassandra-driver的错误版本.或者仍然存在与番石榴库相关的类路径问题,因为cassandra 3.0及更高版本使用guava 16.0.1,上面的讨论表明类路径中可能存在较低版本的番石榴.

这是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>

这些是使用上面的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

以上是我的快照jar中的一些主要依赖项.

Y是CodecNotFoundException？是因为班级路径(番石榴)？或cassandra-driver(cassandra-driver-core-3.0.0-alpha4.jar for datastax cassandra 3.2.1)或由于代码.

另一点是我插入数据类型为时间戳的列的所有日期.

此外,当我进行spark-submit时,我会在日志中看到类路径,还有其他番石榴版本位于hadoop libs下.R这些引起了什么问题？

我们如何在执行spark-submit时指定特定于用户的类路径.这会有帮助吗？

很高兴得到一些关于这些的点.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)

我也有

com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [Math.BigDecimal <-> java.lang.String]

Answer 1

当你调用bind(params...)一个PreparedStatement司机希望你提供值W映射到定制列表类型/ Java类型.

这个错误([timestamp <-> java.lang.String])告诉你没有注册这样的Codec将java映射String到cql timestamp.在java驱动程序中,timestamp类型映射到java.util.Date.所以你有两个选择:

1. 如果要绑定的列用于时间戳,请提供Date-typed值而不是a String.
2. 创建映射的编解码器timestamp <-> String.为此,您可以创建文档站点MappingCodec上描述的子类,将String映射到时间戳:

public class TimestampAsStringCodec extends MappingCodec<String, Date> {
    public TimestampAsStringCodec() { super(TypeCodec.timestamp(), String.class); }

    @Override
    protected Date serialize(String value) { ... }

    @Override
    protected String deserialize(Date value) { ... }
}

然后,您需要注册编解码器:

cluster.getConfiguration().getCodecRegistry()
    .register(new TimestampAsStringCodec());