Dependence on a warm cache

Cases

1. IL-0408 OpenRouter's API returned 500s and false 401 "User not found" errors when its API key cache dropped and came back emptyOpenRouter · 2026

   Root cause Dependency failure

2. IL-0268 AdGuard DNS resolvers in Amsterdam, Frankfurt and London overloaded and answered with timeouts and SERVFAILAdGuard DNS · 2025

   Root cause Faulty deployment

3. IL-0324 Three MediaWiki deployments lost Memcached after a PHP 8.1 rollout and overloaded the External Storage database clusterWikimedia Foundation · 2025

   Root cause Faulty deployment

4. IL-0270 Discord's ScyllaDB authentication cluster overloaded during an OS upgrade, and logins failed for about 50 minutesDiscord · 2023

   Root cause Capacity exhaustion

5. IL-0216 Wikimedia on-wiki search was slow or rejected after a datacenter switchover overloaded one Elasticsearch node in codfwWikimedia Foundation · 2023

   Root cause Software defect

6. IL-0567 Aurora MySQL behind Cookie Run: OvenBreak hit 100% CPU after a sales-ranking feature launch, and players could not playDevsisters · 2023

   Root cause Faulty deployment

7. IL-0217 Honeycomb's main MySQL database locked up under cache-miss reads and ran out of connections, a 68-minute total outageHoneycomb · 2023

   Root cause Software defect

8. IL-0212 Many Slack users could not connect because a Vitess keyspace for channel membership was overloaded by cache-miss queriesSlack · 2022

   Root cause Capacity exhaustion

9. IL-0297 Mezmo users could not sign in and log indexing lagged after the auth cache's Redis servers were OOM killedMezmo · 2019

   Root cause Capacity exhaustion

10. IL-0303 GitHub's MySQL master failed over to a node with a cold buffer pool during a schema migration and GitHub.com went downGitHub · 2012

    Root cause Software defect