我正在尝试从在 IBM Analytics Engine 上运行的 Spark 2.3 连接到在 IBM Cloud 上运行的 ScyllaDB 数据库。
我正在像这样启动火花壳......
$ spark-shell --master local[1] \
--files jaas.conf \
--packages org.apache.spark:spark-sql-kafka-0-10_2.11:2.3.0,datastax:spark-cassandra-connector:2.3.0-s_2.11,commons-configuration:commons-configuration:1.10 \
--conf "spark.driver.extraJavaOptions=-Djava.security.auth.login.config=jaas.conf" \
--conf "spark.executor.extraJavaOptions=-Djava.security.auth.login.config=jaas.conf" \
--conf spark.cassandra.connection.host=xxx1.composedb.com,xxx2.composedb.com,xxx3.composedb.com \
--conf spark.cassandra.connection.port=28730 \
--conf spark.cassandra.auth.username=scylla \
--conf spark.cassandra.auth.password=SECRET \
--conf spark.cassandra.connection.ssl.enabled=true \
--num-executors 1 \
--executor-cores 1
然后执行以下 spark scala 代码：
import com.datastax.spark.connector._
import org.apache.spark.sql.cassandra._
val stocksRdd = sc.cassandraTable("stocks", "stocks")
stocksRdd.count()
但是，我看到一堆警告：
18/08/23 10:11:01 WARN Cluster: You listed xxx1.composedb.com/xxx.xxx.xxx.xxx:28730 in your contact points, but it wasn't found in the control host's system.peers at startup
18/08/23 10:11:01 WARN Cluster: You listed xxx1.composedb.com/xxx.xxx.xxx.xxx:28730 in your contact points, but it wasn't found in the control host's system.peers at startup
18/08/23 10:11:06 WARN Session: Error creating pool to /xxx.xxx.xxx.xxx:28730
com.datastax.driver.core.exceptions.ConnectionException: [/xxx.xxx.xxx.xxx:28730] Pool was closed during initialization
...
但是，在警告中的堆栈跟踪之后，我看到了我期望的输出：
res2: Long = 4
如果我导航到撰写 UI，我会看到一个地图 json：
[
{"xxx.xxx.xxx.xxx:9042":"xxx1.composedb.com:28730"},
{"xxx.xxx.xxx.xxx:9042":"xxx2.composedb.com:28730"},
{"xxx.xxx.xxx.xxx:9042":"xxx3.composedb.com:28730"}
]
似乎警告与地图文件有关。
警告的含义是什么？我可以忽略它吗？
注意：我看到了一个类似的问题，但是我相信这个问题是不同的，因为地图文件和我无法控制 Compose 如何设置 scylladb 集群。