尝试使用 Apache-Spark 和 Scala 连接到远程_2544843时,我遇到了一些麻烦 . 我成功地用 MongoDb 以同样的方式连接过去 .
这次我真的不明白为什么我收到以下错误:
无法在{127.0.0.1}:9042打开与Cassandra的本机连接
我想这是一个依赖和版本问题,但我无法在文档和其他问题上找到与此问题相关的任何内容 .
我基本上设法使用jsch通过ssh-tunnel连接到我的服务器,一切正常 . 然后,我成功地使用 SparkConnectionFactory.scala 连接到本地apache-spark:
package connection
import org.apache.spark.{SparkConf, SparkContext}
class SparkConnectionFactory {
var sparkContext : SparkContext = _
def initSparkConnection = {
val configuration = new SparkConf(true).setMaster("local[8]")
.setAppName("my_test")
.set("spark.cassandra.connection.host", "localhost")
.set("spark.cassandra.input.consistency.level","ONE")
.set("spark.driver.allowMultipleContexts", "true")
val sc = new SparkContext(configuration)
sparkContext = sc
}
def getSparkInstance : SparkContext = {
sparkContext
}
}
并在我的_2544850中调用它:
val sparkConnectionFactory = new SparkConnectionFactory
sparkConnectionFactory.initSparkConnection
val sc : SparkContext = sparkConnectionFactory.getSparkInstance
但是,当我尝试使用以下方法选择Cassandra表中的所有项目时:
val rdd = sc.cassandraTable("my_keyspace", "my_table")
rdd.foreach(println)
我得到了上面写的错误 .
在我的服务器上,我安装了 Scala ~v2.11.6
, Spark ~v2.1.1
, SparkSQL ~v2.1.1
. 当然我有8个核心,复制因子为1.我的 pom.xml
我有:
. . .
<properties>
<scala.version>2.11.6</scala.version>
</properties>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
. . .
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-core_2.10 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.datastax.spark/spark-cassandra-connector_2.10 -->
<dependency>
<groupId>com.datastax.spark</groupId>
<artifactId>spark-cassandra-connector_2.11</artifactId>
<version>2.0.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql_2.10 -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/commons-codec/commons-codec -->
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.9</version>
</dependency>
</dependencies>
Is my issue caused by conflicting versions? If yes, how can I fix this? If not, any hint on what's causing it?
提前致谢 .
1 回答
那就是你需要连接的端口