[ENH] Multi-region, multi-cloud configuration. #6092

rescrv · 2025-12-26T21:16:33Z

Description of changes

This PR introduces the types for multi-region, multi-cloud support.

Test plan

CI

Migration plan

Not applicable yet.

Observability plan

N/A

Documentation Changes

N/A

github-actions · 2025-12-26T21:16:49Z

propel-code-bot · 2025-12-26T21:17:15Z

It introduces a dedicated topology module in rust/types that defines strongly typed region and topology constructs, wraps multi-cloud configuration data with validation and serde integration, and backs these behaviors with tests to enforce the configuration invariants.

Key Changes

• Add rust/types/src/topology.rs with RegionName, TopologyName, ProviderRegion<T>, Topology, and MultiCloudMultiRegionConfiguration<T> plus validation utilities and serde conversions
• Implement ValidationError reporting with deduplicated duplicate-name and unknown-region tracking and human-readable formatting helpers
• Provide comprehensive unit tests covering constructors, serde round-trips, validation failure scenarios, and error-display formatting
• Expose the new topology module through rust/types/src/lib.rs so consumers can import the types

Affected Areas

• rust/types/src/topology.rs
• rust/types/src/lib.rs

This summary was automatically generated by @propel-code-bot

rust/types/src/topology.rs

propel-code-bot · 2025-12-30T21:48:16Z

rust/types/src/topology.rs

+        println!(
+            "region_name_empty error: {:?}",
+            result.as_ref().unwrap_err()
+        );


[Maintainability] Consider removing the println! statements from the tests that check for validation errors. They were likely added for debugging and can clutter the CI logs.

This applies to this test and several others that follow the same pattern (e.g., region_name_too_long, region_name_non_ascii, topology_name_empty, etc.).

Context for Agents

Consider removing the `println!` statements from the tests that check for validation errors. They were likely added for debugging and can clutter the CI logs. This applies to this test and several others that follow the same pattern (e.g., `region_name_too_long`, `region_name_non_ascii`, `topology_name_empty`, etc.). File: rust/types/src/topology.rs Line: 1305

sanketkedia · 2026-01-02T21:24:46Z

rust/types/src/topology.rs

+    /// The name of the preferred region for operations with region affinity.
+    preferred: RegionName,
+    /// The set of provider regions available in this configuration.
+    regions: Vec<ProviderRegion<T>>,


doesn't topologies below already contain the regions? what is this for?

Topologies contains the listing of regions. This is per-region state. So, e.g. we can bind T to a Spanner+Storage config and specify it once per region.

propel-code-bot · 2026-01-02T23:01:12Z

rust/types/src/topology.rs

+use thiserror::Error;
+
+/// Maximum length for region and topology names.
+const MAX_NAME_LENGTH: usize = 32;


[Requirements] The MAX_NAME_LENGTH of 32 seems potentially restrictive. While it covers standard cloud provider region names, it might be too short for custom or on-premise deployments where more descriptive names are common. For example, a name like "corporate-datacenter-building-a-rack-5" would exceed this limit.

To provide more flexibility, consider increasing this limit. A value like 64 would align better with common identifier length limits in various systems (e.g., DNS labels are up to 63 characters) and would be less likely to cause issues for users with custom naming schemes.

Context for Agents

The `MAX_NAME_LENGTH` of 32 seems potentially restrictive. While it covers standard cloud provider region names, it might be too short for custom or on-premise deployments where more descriptive names are common. For example, a name like "corporate-datacenter-building-a-rack-5" would exceed this limit. To provide more flexibility, consider increasing this limit. A value like 64 would align better with common identifier length limits in various systems (e.g., DNS labels are up to 63 characters) and would be less likely to cause issues for users with custom naming schemes. File: rust/types/src/topology.rs Line: 87

I'm keeping 32 for now as we can always up it.