Preserve legacy catalog at catalog-old.data.gov

[SueValente]

Parent Issue: Transition catalog-beta.data.gov to production catalog.data.gov

User Story

In order to give stakeholders, partner organizations, and API consumers a smooth transition
to the new Data.gov catalog, the Data.gov team wants to preserve the current legacy catalog
at catalog-old.data.gov so people have a reference point while they get familiar with the
new system.

Acceptance Criteria

• GIVEN a user navigates to catalog-old.data.gov
  WHEN the page loads
  THEN they see the legacy catalog with all data intact as of the freeze date (TBD)

• GIVEN the legacy catalog is preserved at catalog-old.data.gov
  WHEN a harvest cycle would normally run
  THEN no new harvesting occurs -- the catalog is frozen at a point-in-time snapshot (date TBD)

• GIVEN the transition has been communicated
  WHEN a stakeholder or partner org asks about the old catalog
  THEN they know catalog-old.data.gov exists as a temporary archived reference and that
  catalog.data.gov is the active system going forward

• GIVEN the legacy catalog is preserved
  WHEN the team revisits its status later in 2026
  THEN a sunset plan is in place targeting fall 2026 for decommissioning

Background

When we cut over to the new catalog at catalog.data.gov, we don't want to pull the rug out
from under anyone who depends on the current system. Keeping the old catalog available at
catalog-old.data.gov gives us a few things:

• A safety net if we need to roll back quickly after cutover (just redirect DNS)
• A reference for partner organizations and API consumers who need time to adjust
• A way to compare data between old and new if questions come up during the transition
• Peace of mind for CDO Council members and other stakeholders that nothing is being lost

Harvesting will be frozen so there's no confusion about which catalog has current data.
The plan is to keep catalog-old.data.gov available through fall 2026, then decommission it
once we're confident everyone has migrated and the new system is fully stable.

Communication is key here. We should announce this through the open data listserv (once
we have access), CDO Council channels, and direct outreach to partner organizations.

Security Considerations

• Ensure valid certificates are in place for the catalog-old.data.gov URL
• Disable write/admin access on the legacy system once it's frozen
• Monitor for any security issues in the legacy codebase during the preservation period

Sketch

• Coordinate DNS setup for catalog-old.data.gov with GSA IT / cloud.gov operations
• Freeze harvesting on the legacy system at the agreed-upon date (TBD)
• Disable any scheduled jobs or automated processes on the legacy system
• Verify catalog-old.data.gov loads correctly and existing data is accessible
• Announce catalog-old.data.gov availability through open data listserv and CDO Council
• Document the sunset target (fall 2026) and what triggers decommissioning
• Set a reminder to revisit catalog-old.data.gov status in summer 2026