The dashboard was sporadically hanging for several seconds during task
creation and settings loading due to multiple compounding issues:
- checkForChanges() polled every 1s with SELECT * FROM tasks + full
JSON.stringify comparison, blocking the Node.js event loop. Now uses
incremental polling (only changed tasks via updatedAt filter).
- allocateId() called readConfig() which always ran listWorkflowSteps(),
adding unnecessary DB queries while holding the serialization lock.
Now uses readConfigFast() that skips workflow steps.
- Task creation triggered listWorkflowSteps() up to 3 times per request.
Added in-memory cache with invalidation on create/update/delete.
- Route handlers used getSettings() (slow path) where getSettingsFast()
suffices (POST /tasks, GET /config).
- SSE effect in useTasks had searchQuery and refreshTasks in its
dependency array, causing EventSource teardown/rebuild on every search
change. Moved to refs since the EventSource URL doesn't use searchQuery.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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