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# Spark Connector vs Alternatives

> Source-anchored research for Spark Connector vs Alternatives. Run status: COMPLETED.

Parent: [MongoDB Spark Connector and Databricks Integration](https://llms-explorer.com/tree/mongodb-spark-connector-and-databricks-integration/) · 4 facets · 9 facts · page: https://llms-explorer.com/tree/spark-connector-vs-alternatives/

## How it works

- Choose snapshot and ongoing-change behavior explicitly. Debezium documents initial snapshots followed by streaming and separately configurable snapshot modes; the Spark source documents latest or timestamp startup when no offset exists. These are different bootstrap contracts, so switching tools requires a backfill-and-handoff design. (medium confidence) (verified as of 2026-10-23) — [source](https://debezium.io/documentation/reference/stable/connectors/mongodb.html)
- Full-document output is not sufficient evidence of faithful CDC replication. The Spark source filters events without fullDocument when change.stream.publish.full.document.only is enabled; Debezium separately models delete and tombstone events. Compare delete propagation before selecting either data path. (medium confidence) (verified as of 2026-10-23) — [source](https://www.mongodb.com/docs/spark-connector/current/streaming-mode/streaming-read-config.md)

## How-to and procedures

- Use the MongoDB Spark Connector when a job needs to read MongoDB documents into Spark transformations and write results back; both MongoDB's guide and Databricks' MongoDB examples expose direct DataFrame reads and writes. (high confidence) — [source](https://www.mongodb.com/docs/spark-connector/current/getting-started.md)

## Problems, failure modes and limitations

- Meroxa's April 4, 2025 benchmark compares Conduit v0.13.2 with the MongoDB connector v0.2.2 against Kafka Connect v7.8.1 with MongoDB's Kafka connector v1.15.0. The tests use MongoDB-to-Kafka snapshot and CDC workloads on a four-vCPU t2.xlarge EC2 host, with Kafka and MongoDB provided via Docker containers. Meroxa reports about a 52% higher Conduit message rate in CDC; it does not benchmark the MongoDB Spark Connector, so the headline cannot rank that connector. (low confidence) (verified as of 2025-04-04) — [source](https://meroxa.com/blog/conduit-makes-mongodb-cdc-52percent-faster-than-kafka-connect/)

## Facts and statements

- Kafka is optional for MongoDB-to-Spark streaming: MongoDB documents direct Spark micro-batches as well as a separate MongoDB Kafka source-to-Databricks pipeline. (high confidence) — [source](https://www.mongodb.com/company/blog/technical/how-seamlessly-use-atlas-databricks-lakehouse-together)
- Debezium offers an alternative capture boundary: its MongoDB connector records database changes in Kafka topics, and Lydtech's runnable demonstration separates database application writes from Kafka Connect capture. (high confidence) — [source](https://debezium.io/documentation/reference/stable/connectors/mongodb.html)
- MongoDB describes object-storage alternatives: Atlas Data Federation can export a one-time load to S3; a Kafka source plus S3 sink can stage ongoing changes for Databricks Auto Loader. Staging files still requires ingestion into Delta Lake. (low confidence) (verified as of 2025-12-02) — [source](https://www.mongodb.com/company/blog/technical/how-seamlessly-use-atlas-databricks-lakehouse-together)
- Databricks distinguishes Spark Data Source API jobs for custom ETL and external writes, federation for governed ad-hoc querying, and managed ingestion for persistent replication. This generic comparison does not establish MongoDB support for every alternative; verify a source-specific support matrix before treating them as substitutes. (low confidence) (verified as of 2026-09-28) — [source](https://docs.databricks.com/aws/en/connect/spark-data-sources)
- Kafka buffering helps only after changes reach Kafka. Debezium warns that a long capture outage can exhaust MongoDB oplog history and that consumers must handle duplicate events under failures; adding Kafka does not remove source-retention and replay requirements. (low confidence) — [source](https://debezium.io/documentation/reference/stable/connectors/mongodb.html)
