PySpark Can't Connect to MongoDB, but Command-line Can - mongodb

Question

Trying to load a MongoDB collection into a PySpark DataFrame. First of all.. I'm able to connect using the command line on the NameNode:
mongo mongodb://USER:PASSWORD#HOST/DB_NAME
MongoDB shell version v3.6.3
connecting to: mongodb://HOST/DB_NAME
MongoDB server version: 3.6.3
>
I run the script on the cluster as follows:
spark-submit \
--master yarn \
--deploy-mode client \
--driver-memory 4g \
--executor-memory 2g \
--executor-cores 3 \
--num-executors 10 \
--packages org.mongodb.spark:mongo-spark-connector_2.11:2.4.1 \
load_from_mongo.py
Now I create a SparkSession:
spark = SparkSession.builder \
.appName("TestMongoLoad") \
.config("spark.mongodb.input.uri", 'mongodb://USER:PASSWORD#HOST:27017') \
.config("spark.mongodb.input.database", DB_NAME) \
.config("spark.mongodb.input.collection", COLLECTION_NAME) \
.getOrCreate()
Then I attempt to read in the DataFame:
df = spark.read.format("com.mongodb.spark.sql.DefaultSource") \
.load()
df.show(5, truncate=False)
The result is that it fails authentication. Clearly I'm passing something incorrectly...
Ivy Default Cache set to: /home/ubuntu/.ivy2/cache
The jars for the packages stored in: /home/ubuntu/.ivy2/jars
:: loading settings :: url = jar:file:/home/ubuntu/server/spark-2.4.4-bin-hadoop2.7/jars/ivy-2.4.0.jar!/org/apache/ivy/core/settings/ivysettings.xml
org.mongodb.spark#mongo-spark-connector_2.11 added as a dependency
:: resolving dependencies :: org.apache.spark#spark-submit-parent-caedf270-dd43-42f2-a39e-e3d1b7134046;1.0
confs: [default]
found org.mongodb.spark#mongo-spark-connector_2.11;2.4.1 in central
found org.mongodb#mongo-java-driver;3.10.2 in central
[3.10.2] org.mongodb#mongo-java-driver;[3.10,3.11)
:: resolution report :: resolve 1129ms :: artifacts dl 4ms
:: modules in use:
org.mongodb#mongo-java-driver;3.10.2 from central in [default]
org.mongodb.spark#mongo-spark-connector_2.11;2.4.1 from central in [default]
---------------------------------------------------------------------
| | modules || artifacts |
| conf | number| search|dwnlded|evicted|| number|dwnlded|
---------------------------------------------------------------------
| default | 2 | 1 | 0 | 0 || 2 | 0 |
---------------------------------------------------------------------
:: retrieving :: org.apache.spark#spark-submit-parent-caedf270-dd43-42f2-a39e-e3d1b7134046
confs: [default]
0 artifacts copied, 2 already retrieved (0kB/7ms)
20/02/29 21:26:24 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Traceback (most recent call last):
File "/home/ubuntu/server/load_from_mongo.py", line 124, in <module>
main(args)
File "/home/ubuntu/server/load_from_mongo.py", line 102, in main
keyword_df = getKeywordCorpus(args.begin_dt, args.end_dt)
File "/home/ubuntu/server/load_from_mongo.py", line 79, in getKeywordCorpus
df = spark.read.format("com.mongodb.spark.sql.DefaultSource") \
File "/home/ubuntu/server/spark-2.4.4-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/sql/readwriter.py", line 172, in load
File "/home/ubuntu/server/spark-2.4.4-bin-hadoop2.7/python/lib/py4j-0.10.7-src.zip/py4j/java_gateway.py", line 1257, in __call__
File "/home/ubuntu/server/spark-2.4.4-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/sql/utils.py", line 63, in deco
File "/home/ubuntu/server/spark-2.4.4-bin-hadoop2.7/python/lib/py4j-0.10.7-src.zip/py4j/protocol.py", line 328, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling o57.load.
: com.mongodb.MongoSecurityException: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='USER', source='admin', password=<hidden>, mechanismProperties={}}
at com.mongodb.internal.connection.SaslAuthenticator.wrapException(SaslAuthenticator.java:173)
at com.mongodb.internal.connection.SaslAuthenticator.access$300(SaslAuthenticator.java:40)
at com.mongodb.internal.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:70)
at com.mongodb.internal.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:47)
at com.mongodb.internal.connection.SaslAuthenticator.doAsSubject(SaslAuthenticator.java:179)
at com.mongodb.internal.connection.SaslAuthenticator.authenticate(SaslAuthenticator.java:47)
at com.mongodb.internal.connection.InternalStreamConnectionInitializer.authenticateAll(InternalStreamConnectionInitializer.java:152)
at com.mongodb.internal.connection.InternalStreamConnectionInitializer.initialize(InternalStreamConnectionInitializer.java:63)
at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:127)
at com.mongodb.internal.connection.UsageTrackingInternalConnection.open(UsageTrackingInternalConnection.java:50)
at com.mongodb.internal.connection.DefaultConnectionPool$PooledConnection.open(DefaultConnectionPool.java:390)
at com.mongodb.internal.connection.DefaultConnectionPool.get(DefaultConnectionPool.java:106)
at com.mongodb.internal.connection.DefaultConnectionPool.get(DefaultConnectionPool.java:92)
at com.mongodb.internal.connection.DefaultServer.getConnection(DefaultServer.java:85)
at com.mongodb.binding.ClusterBinding$ClusterBindingConnectionSource.getConnection(ClusterBinding.java:115)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:212)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:206)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:116)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:109)
at com.mongodb.operation.CommandReadOperation.execute(CommandReadOperation.java:56)
at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:179)
at com.mongodb.client.internal.MongoDatabaseImpl.executeCommand(MongoDatabaseImpl.java:184)
at com.mongodb.client.internal.MongoDatabaseImpl.runCommand(MongoDatabaseImpl.java:153)
at com.mongodb.client.internal.MongoDatabaseImpl.runCommand(MongoDatabaseImpl.java:148)
at com.mongodb.spark.MongoConnector$$anonfun$1.apply(MongoConnector.scala:237)
at com.mongodb.spark.MongoConnector$$anonfun$1.apply(MongoConnector.scala:237)
at com.mongodb.spark.MongoConnector$$anonfun$withDatabaseDo$1.apply(MongoConnector.scala:174)
at com.mongodb.spark.MongoConnector$$anonfun$withDatabaseDo$1.apply(MongoConnector.scala:174)
at com.mongodb.spark.MongoConnector.withMongoClientDo(MongoConnector.scala:157)
at com.mongodb.spark.MongoConnector.withDatabaseDo(MongoConnector.scala:174)
at com.mongodb.spark.MongoConnector.hasSampleAggregateOperator(MongoConnector.scala:237)
at com.mongodb.spark.rdd.MongoRDD.hasSampleAggregateOperator$lzycompute(MongoRDD.scala:221)
at com.mongodb.spark.rdd.MongoRDD.hasSampleAggregateOperator(MongoRDD.scala:221)
at com.mongodb.spark.sql.MongoInferSchema$.apply(MongoInferSchema.scala:68)
at com.mongodb.spark.sql.DefaultSource.constructRelation(DefaultSource.scala:97)
at com.mongodb.spark.sql.DefaultSource.createRelation(DefaultSource.scala:50)
at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:318)
at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:223)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:211)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:167)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.mongodb.MongoCommandException: Command failed with error 18 (AuthenticationFailed): 'Authentication failed.' on server HOST:27017. The full response is {"ok": 0.0, "errmsg": "Authentication failed.", "code": 18, "codeName": "AuthenticationFailed"}
at com.mongodb.internal.connection.ProtocolHelper.getCommandFailureException(ProtocolHelper.java:179)
at com.mongodb.internal.connection.InternalStreamConnection.receiveCommandMessageResponse(InternalStreamConnection.java:299)
at com.mongodb.internal.connection.InternalStreamConnection.sendAndReceive(InternalStreamConnection.java:255)
at com.mongodb.internal.connection.CommandHelper.sendAndReceive(CommandHelper.java:83)
at com.mongodb.internal.connection.CommandHelper.executeCommand(CommandHelper.java:33)
at com.mongodb.internal.connection.SaslAuthenticator.sendSaslStart(SaslAuthenticator.java:130)
at com.mongodb.internal.connection.SaslAuthenticator.access$100(SaslAuthenticator.java:40)
at com.mongodb.internal.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:54)
... 48 more

Answer 1

The answer, as #Lamanus alluded above, was to change the URI slightly:
MONGO_URL = "mongodb://USER:PASSWORD#HOST:27017/DB_NAME"
spark = SparkSession.builder \
.appName('TestMongoLoad') \
.config('spark.mongodb.input.uri', MONGO_URL) \
.config('spark.mongodb.input.collection', COLLECTION) \
.getOrCreate()