It looks like you are trying to connect to MongoDB using the mongo-spark-connector_2.12:10.1.1 library, but you are facing issues with the connection. Here are a few things you can try to resolve the issue:

1. Double-check the connection string: Make sure that the connection string you are using is correct and has the right format. You can verify this by connecting to MongoDB directly using the mongo shell or a MongoDB client.
2. Check the Spark logs: Look for any error messages in the Spark logs. This might give you some clues about the issue. You can access the logs from the Spark UI or by running the following command:

$SPARK_HOME/bin/spark-submit --class org.apache.spark.examples.SparkPi --master yarn --deploy-mode client --driver-memory 4g --executor-memory 2g --executor-cores 1 --num-executors 2 --conf spark.eventLog.enabled=true --conf spark.eventLog.dir=hdfs:///spark-history --conf spark.history.fs.logDirectory=hdfs:///spark-history --jars /path/to/mongo-spark-connector_2.12-10.1.1.jar /path/to/your/application.jar

3) Try a different version of the library: If the above two steps don't work, you can try using a different version of the mongo-spark-connector library. You can find the list of available versions here: https://mvnrepository.com/artifact/org.mongodb.spark/mongo-spark-connector_2.12

4) Check compatibility with MongoDB server version: Make sure that the version of mongo-spark-connector library you are using is compatible with the version of MongoDB server you are using. You can check the compatibility matrix here: https://docs.mongodb.com/spark-connector/master/#compatibility-matrix

I hope these suggestions help you resolve the issue.