Pre-load AR schemas and disconnect before forking DSL workers#2522
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Pre-load AR schemas and disconnect before forking DSL workers#2522
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Pre-load the schema for all ActiveRecord models in the parent process before forking parallel workers, so the schema cache is inherited via copy-on-write. Then clear all database connections so forked children don't inherit stale connections from the parent, avoiding exceeding connection limits (e.g. Semian ticket counts).
Morriar
reviewed
Mar 4, 2026
| # Disconnect all database connections before forking workers. The migration check and schema pre-loading | ||
| # above may have established connections; clearing them ensures forked children don't inherit stale | ||
| # connections from the parent, avoiding exceeding connection limits (e.g. Semian ticket counts). | ||
| ::ActiveRecord::Base.connection_handler.clear_all_connections! |
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Do we need this even with @number_of_workers == 1?
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Motivation
With multiple workers, we've been hitting connection limits on CI when verifying DSL RBI files. This PR attempts to fix that problem.
Implementation
Pre-load the schema for all ActiveRecord models in the parent process before forking parallel workers, so the schema cache is inherited via copy-on-write. Then clear all database connections so forked children don't inherit stale connections from the parent. Together, this should ensure that child processes do not make any database connections, since most of our introspection should just be hitting the schema.
Tests
No new tests.