如何从 spark 建立与 Cassandra 的区域/dc 感知连接？

Question

我正在使用 spark-sql 2.4.1、spark-cassandra-connector_2.11-2.4.1.jar 和 java8。 当我尝试从遇到的表中获取数据时

java.io.IOException: Failed to write statements to keyspace1.model_vals. The
latest exception was
  An unexpected error occurred server side on cassandra-node1: com.google.common.util.concurrent.UncheckedExecutionException: com.google.common.util.concurrent.UncheckedExecutionException: java.lang.RuntimeException: org.apache.cassandra.exceptions.ReadTimeoutException: Operation timed out - received only 0 responses.

那么如何从 spark 代码建立到 Cassandra db 的 zone/dc 感知连接？

YML

现有一个

spring:
  data:
      cassandra:
        keyspace-name: raproduct
        contact-points:
                    - cassandra-node1
                    - cassandra-node2
        port: 9042 

改为

spring:
  data:
      cassandra:
        connection:
          local_dc: southeast-1
        keyspace-name: raproduct
        contact-points:
                    - cassandra-node1
                    - cassandra-node2
        port: 9042 

问题

但它没有反映/应用更改的“local_dc”。 在spring-data中怎么做？

Answer 1

检查Spark Connector documentation 和Configuration Reference - Cassandra Connection Parameters。这似乎可以通过在连接配置中设置spark.cassandra.connection.local_dc 属性来完成：

val conf = new SparkConf(true)
        .set("spark.cassandra.connection.host", "192.168.1.10")
        .set("spark.cassandra.auth.username", "flynn")            
        .set("spark.cassandra.auth.password", "reindeerFlotilla82")
        .set("spark.cassandra.connection.local_dc", "encom_west1_dc")

val sc = new SparkContext("spark://192.168.1.133:7077", "test", conf)

不确定您的连接配置代码是什么样的，但请尝试设置该 spark.cassandra.connection.local_dc 属性，看看您会得到什么。