What they are
- Opal
- Mature platform by OBiBa
- Full data management: storage, harmonisation, metadata, cataloguing
- Widely used in DataSHIELD documentation and consortia
- Armadillo
- Lightweight server by MOLGENIS team (Support & Development)
- Built specifically for DataSHIELD federated analysis
- Easier deployment, fewer dependencies
Architecture & Storage
- Opal
- Uses relational DBs (MySQL, PostgreSQL, MariaDB) or MongoDB
- Stores data and metadata in databases
- Supports complex workflows
- Armadillo
- Stores data on the filesystem (e.g. Parquet files)
- Uploads via UI or R package
- Simpler, less infrastructure heavy
Features
- Opal
- Rich functionality: harmonisation, metadata, cataloguing
- Multiple R servers, horizontal scaling
- Advanced admin and access control
- Armadillo
- Focused on core federated analysis features
- Profiles: named/versioned DS package collections
- Permissions and function whitelisting
- Lightweight and user-friendly
Pros & Cons
- Opal
- ✅ Mature and feature-rich
- ✅ Good for large, complex infrastructures
- ❌ Higher complexity and overhead
- Armadillo
- ✅ Lightweight, quick to deploy
- ✅ Easier for cohorts with modest resources
- ❌ Fewer features (e.g. less advanced harmonisation)
- ❌ Newer, still catching up in some areas
When to use
- Choose Opal if:
- You need full data management, metadata and harmonisation
- You operate in a large consortium with complex workflows
- Choose Armadillo if:
- You want lightweight, easy deployment
- You mainly need secure federated analysis
- Your team has limited IT resources and want Molgenis Support