Source: TechRepublic (original coverage, January 2017)
What Is AWS Cloud Directory?
Amazon Web Services launched Cloud Directory in January 2017 as a fully managed, purpose-built service for storing and querying hierarchical data at cloud scale. Unlike traditional directory services — such as Active Directory Lightweight Directory Services (AD LDS) or LDAP-based directories — which constrain data to a single hierarchy, Cloud Directory allows administrators to model the same data across multiple independent hierarchies simultaneously.
The Problem With Single-Hierarchy Directories
Conventional directory tools were designed around a single tree structure. This works well for straightforward use cases — for example, a simple organizational chart — but creates friction when the same underlying objects (employees, devices, locations) need to be queried and navigated from multiple perspectives. Workarounds typically involve duplicating data across separate directories or building custom application logic, both of which introduce maintenance overhead and consistency risks.
Multi-Dimensional Hierarchies With Schemas and Facets
Cloud Directory addresses this limitation through a combination of schemas and facets. A schema defines the types of objects that can exist in a directory, while facets allow additional attributes to be attached to those objects. By composing schemas and facets, a single directory can support multiple overlapping hierarchies without duplicating the underlying data.
AWS engineer Jeff Barr described the pattern in an AWS blog post at launch:
“For example, your first hierarchy could mirror your org chart. Later, you could add an additional facet to track some additional properties for each employee, perhaps a second phone number or a social network handle. After that, you could create a geographically oriented hierarchy within the same data: Countries, states, buildings, floors, offices, and employees.”
Jeff Barr, AWS Blog
In practice, this means an enterprise could simultaneously navigate a directory by reporting structure, physical location, and cost center — all within the same data store, without managing three separate directories.
Scalability and Schema Sharing
AWS stated at launch that Cloud Directory is designed to scale to hundreds of millions of objects. Because the service is fully managed, AWS handles provisioning, patching, and availability — there are no directory servers for teams to operate.
A notable architectural feature is extensible schema sharing: multiple applications can share the same directory schema, and each application can independently extend that schema for its own needs. This design allows teams to avoid data duplication while still giving individual applications the flexibility to store application-specific attributes.
Security: Encryption at Rest and in Transit
Cloud Directory includes built-in encryption for data both at rest and in transit. Encryption keys are managed through the AWS Key Management Service (KMS) using 256-bit keys. The service also provides built-in search capabilities, reducing the need for external indexing layers.
Regional Availability at Launch
At the time of launch in January 2017, Cloud Directory was available in the following AWS regions:
- US East (Northern Virginia)
- US East (Ohio)
- US West (Oregon)
- EU (Ireland)
- Asia Pacific (Sydney)
- Asia Pacific (Singapore)
Regional availability has likely expanded since the original launch. Check the AWS Cloud Directory product page for the current list of supported regions.
Pricing at Launch
AWS offered a free tier for the first 12 months, covering 100,000 read API calls, 10,000 write API calls per month, and 1 GB of storage. Beyond the free tier — or after the 12-month period — pricing was structured as follows at launch:
| Resource | Price (at launch) |
|---|---|
| Storage | $0.25 per GB per month |
| Reads | $0.0040 per 10,000 read API calls |
| Writes | $0.0043 per 1,000 write API calls |
Note: These prices are from the January 2017 announcement. Current pricing may differ. Always verify against the official AWS pricing page before budgeting for production use.
Key Takeaways for DevOps and Platform Teams
- Multi-hierarchy support removes the need to maintain separate directories for different organizational views of the same data.
- Fully managed operation eliminates directory server maintenance and patching overhead.
- Extensible schemas let multiple applications share a single source of truth while independently adding application-specific attributes.
- KMS-backed encryption satisfies common compliance requirements for data at rest and in transit.
- Massive scalability (hundreds of millions of objects) makes it viable for large enterprise use cases such as device registries, user directories, and network topology maps.