Rails Daily: Connection Pool Deadlocks and Cache Batching
Rails engineers landed two related fixes to connection pool locking and pinning that address real test-suite deadlocks and failures, alongside a follow-up schema cache optimization and a cluster of documentation accuracy fixes.
Duration: PT2M40S
Episode overview
This episode is a short developer briefing from Rails Daily.
It explains recent repository work in plain language.
- Show: Rails Daily
- Published: 2026-08-16T06:01:17Z
- Audio duration: PT2M40S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good morning. It's August 16th, 2026, and this is Rails Daily.
Today's top story is connection pool safety. Nicolas Va's PR 58490 fixes a genuine ABBA deadlock in ConnectionPool's checkout: when one test example unpins a connection while another thread checks out a new one, the pool could hold one lock while verifying another, inverting lock order and freezing the process. This…
That same pinning mechanism shows up again in ngan's PR 58489, tracking fixture connection pools as they're pinned. This one came directly out of a CI failure surfaced while testing the schema cache change in PR 58488 - a test blew up because it tried to unpin a connection that was never tracked as pinned. Together,…
Second theme: schema cache performance. Ngan's PR 58488 is a direct follow-up to earlier batching work in issue 58421. Previously, building the schema cache read primary keys and indexes one table at a time. Now those reads happen once for the whole list of tables, cutting redundant statements when a cache is…
Third theme: documentation accuracy. Two separate PRs from contributor "55728" corrected return-value examples - PR 58487 fixed CollectionProxy's delete_all, which returns a count, not an…
Se…
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