英文:
Databricks Notebook Scala Spark Connect to MongoDB Could not initialize class com.mongodb.spark.config.ReadConfig$
问题
我正在使用 Databricks 的 Scala 笔记本与 Spark 连接到 MongoDB,我试图理解为什么在尝试连接到 MongoDB 集群时会出现以下错误。我只是想从数据库中读取数据,但不确定为什么会一直出现这个错误。
java.lang.NoClassDefFoundError: Could not initialize class com.mongodb.spark.config.ReadConfig$
我尝试从 MongoDB 中读取数据的代码如下所示。
import org.apache.log4j.{Level, Logger}
import org.apache.spark.ml.evaluation.RegressionEvaluator
import org.apache.spark.ml.recommendation.ALS
import org.apache.spark.ml.tuning.{ParamGridBuilder, TrainValidationSplit}
import org.apache.spark.sql.SQLContext
import org.apache.spark.{SparkConf, SparkContext}
import com.mongodb.spark.MongoSpark
import com.mongodb.spark.config.{ReadConfig, WriteConfig}
import com.mongodb.spark._
import com.mongodb.spark.config._
val data = spark.read.format("com.mongodb.spark.sql.DefaultSource").option("database", "sample_airbnb").option("collection", "listingsAndReviews").load()
data.show()
我还在笔记本库中安装了以下库。
org.mongodb.spark:mongo-spark-connector_2.12:2.4.0
mongodb_driver_3_12_3_javadoc.jar
mongodb_driver_3_12_3_javadoc.jar
bson_3_12_3_javadoc.jar
以下是用于 Spark 配置的 URI。
spark.mongodb.input.uri mongodb+srv://<user>:<password>@cluster0-ofrzm.azure.mongodb.net/test?retryWrites=true&w=majority
spark.mongodb.output.uri mongodb+srv://<user>:<password>@cluster0-ofrzm.azure.mongodb.net/test?retryWrites=true&w=majority
spark.databricks.delta.preview.enabled true
非常感谢您的帮助!
英文:
I'm using a Databricks Scala notebook with Spark to connect to MongoDB and I'm trying to understand why I'm getting this error when I try to connect to my MongoDB cluster. I simply want to able to read my from database but I'm not sure why this error keeps coming up.
java.lang.NoClassDefFoundError: Could not initialize class com.mongodb.spark.config.ReadConfig$
My code where I'm attempting to read from MongoDB is shown here.
import org.apache.log4j.{Level, Logger}
import org.apache.spark.ml.evaluation.RegressionEvaluator
import org.apache.spark.ml.recommendation.ALS
import org.apache.spark.ml.tuning.{ParamGridBuilder, TrainValidationSplit}
import org.apache.spark.sql.SQLContext
import org.apache.spark.{SparkConf, SparkContext}
import com.mongodb.spark.MongoSpark
import com.mongodb.spark.config.{ReadConfig, WriteConfig}
import com.mongodb.spark._
import com.mongodb.spark.config._
val data = spark.read.format("com.mongodb.spark.sql.DefaultSource").option("database", "sample_airbnb").option("collection", "listingsAndReviews").load()
data.show()
I've also installed the following libraries in my notebook library
org.mongodb.spark:mongo-spark-connector_2.12:2.4.0
mongodb_driver_3_12_3_javadoc.jar
mongodb_driver_3_12_3_javadoc.jar
bson_3_12_3_javadoc.jar
These are the uri used for the spark config
spark.mongodb.input.uri mongodb+srv://<user>:<password>@cluster0-ofrzm.azure.mongodb.net/test?retryWrites=true&w=majority
spark.mongodb.output.uri mongodb+srv://<user>:<password>@cluster0-ofrzm.azure.mongodb.net/test?retryWrites=true&w=majority
spark.databricks.delta.preview.enabled true
Any help is greatly appreciated!
答案1
得分: 1
我在Dataproc上使用pyspark遇到了相同的连接问题
我的解决方法:
安装这些Jars
https://mvnrepository.com/artifact/org.mongodb.spark/mongo-spark-connector_2.11/2.4.0
https://repo1.maven.org/maven2/org/mongodb/bson/
https://repo1.maven.org/maven2/org/mongodb/mongodb-driver/
https://repo1.maven.org/maven2/org/mongodb/mongodb-driver-core/
Pyspark:
from pyspark.sql import SparkSession
spark = SparkSession.builder\
.master('local')\
.config('spark.mongodb.input.uri', 'mongodb://{ Host }:{ Port }/{ DB }.{ Collection }')\
.config('spark.mongodb.output.uri', 'mongodb://{ Host }:{ Port }/{ DB }.{ Collection }')\
.config('spark.jars.packages', 'org.mongodb.spark:mongo-spark-connector_2.11-2.4.0')\
.getOrCreate()
df = spark.read\
.format("com.mongodb.spark.sql.DefaultSource")\
.option("database",{ DB })\
.option("collection", { Collection })\
.load()
英文:
I have same connection problem on dataproc using pyspark
my solution:
Install these jars
https://mvnrepository.com/artifact/org.mongodb.spark/mongo-spark-connector_2.11/2.4.0
https://repo1.maven.org/maven2/org/mongodb/bson/
https://repo1.maven.org/maven2/org/mongodb/mongodb-driver/
https://repo1.maven.org/maven2/org/mongodb/mongodb-driver-core/
Pyspark:
from pyspark.sql import SparkSession
spark = SparkSession.builder\
.master('local')\
.config('spark.mongodb.input.uri', 'mongodb://{ Host }:{ Port }/{ DB }.{ Collection }')\
.config('spark.mongodb.output.uri', 'mongodb://{ Host }:{ Port }/{ DB }.{ Collection }')\
.config('spark.jars.packages', 'org.mongodb.spark:mongo-spark-connector_2.11-2.4.0')\
.getOrCreate()
df = spark.read\
.format("com.mongodb.spark.sql.DefaultSource")\
.option("database",{ DB })\
.option("collection", { Collection })\
.load()
答案2
得分: 0
可能涉及以下不同问题:
- 您正在使用针对Scala 2.12编译的连接器,但在使用Scala 2.11的Databricks运行时上运行 - 这很可能是问题,因为发布了使用Scala 2.12的DBR 7.0几乎晚了将近2个月。 一个经验法则是:对于DBR < 7.0,使用带有名称中的
_2.11
的2.4.x版本的构件,对于DBR >= 7.0,使用_2.12
和该库的3.0.0版本 - 您没有下载所有依赖项。 连接器依赖许多其他库,这些库需要可用。 最好将库指定为Maven坐标:
org.mongodb.spark:mongo-spark-connector_2.11-2.4.0
- 这将拉取所有必要的依赖项
英文:
There could be different issues related to this:
- You're using connector compiled with Scala 2.12 on Databricks runtime that uses Scala 2.11 - this is most probable issue, as DBR 7.0 that uses Scala 2.12 was released almost 2 months later. The rule of thumb - for DBR < 7.0, use artifact 2.4.x with
_2.11
in name, for DBR >= 7.0, use_2.12
and version 3.0.0 of that library - You don't have all dependencies downloaded. Connector depends on many other libraries that need to be available. It's better to specify library as Maven coordinates:
org.mongodb.spark:mongo-spark-connector_2.11-2.4.0
- this will pull all necessary dependencies
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库,让每个人都能够通过互相帮助和分享经验来进步。
评论