无法从Spark连接到Cassandra(联系点包含多个数据中心) [英] Cannot connect to Cassandra from Spark (Contact points contain multiple data centers)

问题描述

我正在尝试运行我的第一个spark作业(访问Cassandra的Scala作业)，该作业失败并显示以下错误:

I am trying to run my first spark job (a Scala job that accesses Cassandra) which is failing and showing the following error :

java.io.IOException: Failed to open native connection to Cassandra at {<ip>}:9042
at com.datastax.spark.connector.cql.CassandraConnector$.com$datastax$spark$connector$cql$CassandraConnector$$createSession(CassandraConnector.scala:164)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:150)
at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$2.apply(CassandraConnector.scala:150)
at com.datastax.spark.connector.cql.RefCountedCache.createNewValueAndKeys(RefCountedCache.scala:31)
...........
............
Caused by: java.lang.IllegalArgumentException: Contact points contain multiple data centers: 
at com.datastax.spark.connector.cql.LocalNodeFirstLoadBalancingPolicy.init(LocalNodeFirstLoadBalancingPolicy.scala:47)
at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:1099)
at com.datastax.driver.core.Cluster.getMetadata(Cluster.java:271)
at com.datastax.spark.connector.cql.CassandraConnector$.com$datastax$spark$connector$cql$CassandraConnector$$createSession(CassandraConnector.scala:157)

我们在做什么错了?

我正在使用:

• 火花1.5.2
• Apache Cassandra 2.1.10
• spark-cassandra连接器1.3.1 /1.5.0-M2(尝试了两个连接器)
• Scala版本2.10.4

• Spark 1.5.2
• Apache Cassandra 2.1.10
• spark-cassandra connector 1.3.1 /1.5.0-M2 (tried both connectors)
• Scala version 2.10.4

推荐答案

->据作者称，正在解决此问题.请参阅此答案下方的评论.

--> According to author there a work in progress to fix this. See comments below this answer.

我在文档中找到了它，希望对您有所帮助:

I found this in the documentation, I hope it will help you :

override def init(cluster: Cluster, hosts: JCollection[Host]) {
    nodes = hosts.toSet
    // use explicitly set DC if available, otherwise see if all contact points have same DC
    // if so, use that DC; if not, throw an error
    dcToUse = localDC match { 
      case Some(local) => local
      case None => 
        val dcList = dcs(nodesInTheSameDC(contactPoints, hosts.toSet))
        if (dcList.size == 1) 
            dcList.head
        else 
            throw new IllegalArgumentException(s"Contact points contain multiple data centers: ${dcList.mkString(", ")}")
    }
    clusterMetadata = cluster.getMetadata
}

这篇关于无法从Spark连接到Cassandra(联系点包含多个数据中心)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！