UA App Persistor & UA License download jobs can run at the same time which can cause them to reload tracking cache at the same time which in turn can result in semaphore exhaustion and node(s) being inaccessible.
Steps to Reproduce
As this issue is intermittent, exact steps to reproduce are not available. Generally this issue will present with long running UsageAnalytics jobs on scheduler.workers and/or multiple scheduler.workers running the same UsageAnalytics job.
If you believe your instance is affected by this issue, please contact ServiceNow Customer Support to have the affected node restarted.
Related Problem: PRB1266341