Principle:Apache Spark Source Compilation
| Property | Value |
|---|---|
| source | Doc: Maven Documentation |
| domain | Build_Systems, Compilation |
Overview
A multi-module build process that compiles a large-scale polyglot project (Scala, Java, Python, R) into deployable artifacts using profile-based configuration.
Description
Apache Spark uses Maven as its primary build system with an extensive profile mechanism to enable or disable optional components. The compilation process manages a complex dependency graph of approximately 30 Maven modules spanning multiple languages. Maven profiles allow selective inclusion of features like Kubernetes support, YARN integration, Hive connectivity, and various Hadoop versions without requiring separate build configurations. This addresses the challenge of building a single project that must support diverse deployment targets.
The compilation pipeline involves several stages:
- Dependency Resolution -- Maven resolves all inter-module and external dependencies, downloading artifacts from remote repositories as needed.
- Module Ordering -- The Maven reactor analyzes the module dependency graph and determines the correct build order.
- Profile Activation -- Active profiles inject additional dependencies, source directories, and plugin configurations into the build.
- Artifact Packaging -- Each module produces its own JAR, with assembly modules creating aggregate distribution artifacts.
Usage
Use this when building Spark from source for development, testing, or creating custom distributions. Select appropriate Maven profiles based on the target deployment environment (e.g., -Pkubernetes for K8s, -Pyarn for YARN).
Common scenarios include:
- Building a custom Spark distribution for a specific cluster manager
- Compiling Spark with or without optional language bindings (R, Python)
- Creating test builds during development with minimal profiles for faster iteration
- Producing release artifacts with all supported profiles enabled
Theoretical Basis
Multi-module builds use a directed acyclic graph (DAG) of module dependencies. Maven's reactor sorts modules topologically, building dependencies before dependents. Profile-based configuration implements the Strategy pattern at the build level -- the same build system produces different artifacts based on active profiles.
The build process can be expressed in pseudocode:
# Pseudocode for multi-module profile-based compilation
resolve_module_dag()
topological_sort(modules)
for each module:
compile(sources, active_profiles)
package(artifacts)
This approach provides several theoretical guarantees:
- Deterministic ordering -- Topological sort ensures no module is compiled before its dependencies.
- Composability -- Profiles can be combined freely (e.g.,
-Pkubernetes -Pyarn -Phive) to produce precisely the desired feature set. - Incremental correctness -- The clean lifecycle ensures no stale artifacts from previous builds contaminate the current compilation.