Delta-Ceph

This project aims to interconnect Delta Lake with Ceph. The interconnection is particularly aimed at offloading operations from compute- to storage systems, when using Delta Lake together with Spark to compute data.

In a layered list, you will find the following technologies, starting from a user point-of-view, going deeper:

1. Apache Spark
2. Delta Lake
3. Spark (Delta Lake uses Spark internally)
4. Arrow-Spark
5. Apache Arrow (C++ core)
6. Skyhook
7. Ceph

Compiling this project

This project uses this custom flavor of Delta Lake, that allows us to capture and forward data reading/writing to Arrow-Spark.

1. You must compile custom Delta Lake. For build instructions on how to do this, refer to the repository.
2. Build Arrow-Spark, and make sure you have it in your local maven repository. For build instructions on how to do this, refer to the repository.
3. Once you have finished step 1, i.e, you have the custom Delta Lake as a JAR file at some/path/custom_delta.jar, execute the following in the root folder of this project:

mkdir depjars
cp some/path/custom_delta.jar depjars/

4. Finally, choose one of the following commands to build:
   1. ./gradlew shadowJar builds the full JAR file, with all dependencies included.
   2. ./gradlew lightJar builds a JAR file, skipping a bunch of dependencies that Apache Spark already has. This is a useful build target when planning to deploy on a Spark cluster.
   3. ./gradlew essentialJar builds a JAR file, skipping all but the absolute essentials. This is a useful build target when planning to deploy on a Spark production cluster.

After compilation, you will find the output JAR in:

app/build/libs/app-all.jar       (if shadowJar-compiled)
app/build/libs/app-light.jar     (if lightJar-compiled)
app/build/libs/app-essential.jar (if essentialJar-compiled)