fix(perf): Store subway status in ETS, rather than a GenServer's state#3296
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thecristen
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Jun 30, 2026
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Scope
Turns out - having every consumer request subway status from the
SubwayCacheGenServer raises the possibility of overwhelming the GenServer, since GenServers are a single thread.This change has the homepage controller process reach directly into an ETS table instead (well, through the
SubwayCachemodule, but at least it doesn't useGenServer.call).Asana Ticket: 📈 Don't interact with SystemStatus.SubwayCache per page load
Implementation
SystemStatus.SubwayCachestill alerts consumers when there's been an update.Screenshots
No visible change.
How to test
Observe that subway status still works as usual, and even that the subway alerts page still live-updates!