Please modify your drivers so our java applications can encrypt and decrypt from the mainframe (zOS) UNIX environment. This missing feature is a road-block to our migration to Atlas.

We have multiple Java applications that run on an IBM mainframe. Those applications read and write into MongoDB collections, like inserting Mainframe data into MongoDB collections. The mongo-crypt driver for CSFLE does not work on the Mainframe UNIX environment.

Company policy states we have to encrypt all PHI/PII data prior to inserting the data into Atlas.

I had opened a support ticket with MongoDB and the final reply was you do not support zOS and to put in this request. (Case number 00802484)

Here is the error message I shared with MongoDB:
Exception in thread "main" java.lang.UnsatisfiedLinkError: Native library (com/sun/jna/z/os-s390/libjnidispatch.so) not found in resource path (Ýfile:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/,
file:/ST/usr/lpp/java/IBM/J8.0/lib/, file:/ST/usr/lpp/java/IBM/J8.0/lib/ext/,
file:/ST/usr/lpp/java/json/org.json-20120521.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/CDRMigrateAccumsToAtlas.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/bson-4.2.3.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/jna-5.6.0.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/json-20160810.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/logback-classic-1.2.3.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/logback-core-1.2.3.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/mongodb-crypt-1.2.0.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/mongodb-driver-core-4.2.3.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/mongodb-driver-sync-4.2.3.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/recordio.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/slf4j-api-1.7.6.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/vault-java-driver-5.1.0.jar,
file:/sharedappdev/test/CD/apps/mongopoc/mongo40apps/*.mar¨)
at com.sun.jna.Native.loadNativeDispatchLibraryFromClasspath(Native.java:1032)
at com.sun.jna.Native.loadNativeDispatchLibrary(Native.java:988)
at com.sun.jna.Native.<clinit>(Native.java:195)

Given 2 generic POJOs that include references to each other such as:

package com.example;

public class Course {
    Student _student;

    public void setStudent(Student student) {
      _student = student;
    }

    public Student getStudent() {
      return _student;
    }
}

package com.example;

public class Student {
    private Course _course;

    public void setCourse(Course course) {
      _course = course;
    }
    public Course getCourse() {
      return _course;
    }
}

It would be useful to have a configuration mechanism to prevent Maximum serialization depth exceeded exceptions from being thrown.

package com.example;

import com.mongodb.ConnectionString;
import com.mongodb.MongoClientSettings;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

import org.bson.Document;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.codecs.pojo.PojoCodecProvider;

import static org.bson.codecs.configuration.CodecRegistries.fromProviders;
import static org.bson.codecs.configuration.CodecRegistries.fromRegistries;

public class App {
  public static void main(final String[] args) {
    CodecRegistry pojoCodecRegistry = fromProviders(PojoCodecProvider.builder().automatic(true).build());
    CodecRegistry codecRegistry = fromRegistries(MongoClientSettings.getDefaultCodecRegistry(),
    pojoCodecRegistry);
    MongoClientSettings clientSettings = MongoClientSettings.builder()
    .applyConnectionString(new ConnectionString("mongodb://localhost:27017"))
    .codecRegistry(codecRegistry)
    .build();

    MongoClient mongoClient = MongoClients.create(clientSettings);
        MongoDatabase database = mongoClient.getDatabase("test");

        MongoCollection<Student> students = database.getCollection("students", Student.class);
        MongoCollection<Course> courses = database.getCollection("courses", Course.class);

        students.deleteMany(new Document());
        courses.deleteMany(new Document());

        Student student = new Student();
        Course course = new Course();

        student.setCourse(course);
        course.setStudent(student);

        students.insertOne(student);
        courses.insertOne(course);

        System.out.println(students.find(new Document()).first());
        System.out.println(courses.find(new Document()).first());
  }
}

The above would result in the following:

Exception in thread "main" org.bson.BsonSerializationException: Maximum serialization depth exceeded (does the object being 
serialized have a circular reference?).
        at org.bson.AbstractBsonWriter.writeStartDocument(AbstractBsonWriter.java:285)
        at com.mongodb.internal.connection.BsonWriterDecorator.writeStartDocument(BsonWriterDecorator.java:48)
        at com.mongodb.internal.connection.LevelCountingBsonWriter.writeStartDocument(LevelCountingBsonWriter.java:42)      
        at com.mongodb.internal.connection.IdHoldingBsonWriter.writeStartDocument(IdHoldingBsonWriter.java:78)
        at org.bson.codecs.pojo.PojoCodecImpl.encode(PojoCodecImpl.java:94)
        at org.bson.codecs.pojo.LazyPojoCodec.encode(LazyPojoCodec.java:47)
        at org.bson.codecs.EncoderContext.encodeWithChildContext(EncoderContext.java:91)
        at org.bson.codecs.pojo.PojoCodecImpl.encodeValue(PojoCodecImpl.java:181)
        at org.bson.codecs.pojo.PojoCodecImpl.encodeProperty(PojoCodecImpl.java:169)
        at org.bson.codecs.pojo.PojoCodecImpl.encode(PojoCodecImpl.java:106)
        at org.bson.codecs.pojo.LazyPojoCodec.encode(LazyPojoCodec.java:47)
        at org.bson.codecs.EncoderContext.encodeWithChildContext(EncoderContext.java:91)
....... etc

I am working on a mongodb connector for the Apache Flink project - https://flink.apache.org/

Internally, Flink is using java serialization to save the records it is working on in a state which in turn used to recover from failures etc, as well as for passing records between different tasks in the pipeline.
I have noticed the mongodb client model classes are not Serializable for instance, classes such as WriteModel https://github.com/mongodb/mongo-java-driver/blob/master/driver-core/src/main/com/mongodb/client/model/WriteModel.java and its subclasses or the different Options like ReplaceOptions https://github.com/mongodb/mongo-java-driver/blob/master/driver-core/src/main/com/mongodb/client/model/ReplaceOptions.java

is there a reason for these classes to not be declared Serializable? Is there a way to contribute to the Java driver project by opening a PR that addresses this?

I was building the URI in a spring configuration file as
spring.data.mongodb.uri=${MONGODB_URI}/test?retryWrites=true&w=majority

where MONGODB_URI came from a kubernetes secret (as it contains user & password)

somehow a new-line had slipped into the kubernetes secret, so the query was effectively asking for "fpos-dev-pl-1.kqybg.mongodb.net\n"

Besides learning how to correctly configure secrets, I learned in the process that neither Spring nor mongo was validating that spring.data.mongodb.uri was a well-formed URI and the application failed to start with error messages relating to not finding DNS and not being able to resolve the TXT record. This was very confusing.

The driver should accept a URI parameter (instead of a String) and ensures that it is valid.