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# Spark + Comet Benchmark Configuration

How Spark 4.1.3 with [Apache DataFusion Comet](https://github.com/apache/datafusion-comet)
1.1.0-rc2 was configured for the TPC-H SF1000 results on the
[benchmarking page](index.md). The cluster, data and queries are described in
[Benchmark Environment](environment.md).

## Comet configuration

The Spark + Comet run adds these settings to the [Spark configuration](spark.md):

| Key                                    | Value                                                              |
| -------------------------------------- | ------------------------------------------------------------------ |
| `spark.plugins`                        | `org.apache.spark.CometPlugin`                                     |
| `spark.comet.enabled`                  | `true`                                                             |
| `spark.shuffle.manager`                | `org.apache.spark.sql.comet.execution.shuffle.CometShuffleManager` |
| `spark.memory.offHeap.enabled`         | `true`                                                             |
| `spark.memory.offHeap.size`            | `32G`                                                              |
| `spark.comet.exec.memoryPool.fraction` | `0.8`                                                              |

The run also enabled Comet's explain and fallback logging. Everything else is
left at Comet's defaults.

## Reproducing

Start from the [Spark](spark.md) `spark-submit` command, add the Comet JAR to
the driver and executor classpath (see the
[Comet installation guide](https://datafusion.apache.org/comet/user-guide/latest/installation.html))
and add the settings above:

```sh
  --conf spark.plugins=org.apache.spark.CometPlugin \
  --conf spark.shuffle.manager=org.apache.spark.sql.comet.execution.shuffle.CometShuffleManager \
  --conf spark.memory.offHeap.enabled=true \
  --conf spark.memory.offHeap.size=32G \
  --conf spark.comet.exec.memoryPool.fraction=0.8
```