Illustrative scenarioDate not recordedIllustrative scenario

WebSocket Connection Thundering Herd on Load Balancer Restart

Simultaneous disconnect of 500,000 active WebSocket clients during proxy restart saturated auth services upon reconnection.

Illustrative scenario, not a real incident

A composite failure pattern written by CollectSEA for learning and demos. It is NOT a documented real-world incident and has no primary source.

What happened

    Contributing factors stated by the source

    • Simultaneous disconnect of 500,000 active WebSocket clients during proxy restart saturated...

    The failure pattern

    Retry amplification and runaway resource consumptionRetries, loops or an expensive input multiply load until a partial failure becomes a full outage or a runaway bill.How to prevent it Partial success leaves systems out of syncA multi-step workflow half-completes, or events arrive out of order, and two systems now disagree about what happened.How to prevent it
    Watch the pattern: Retry amplification and runaway resource consumption

    Related standards

    CollectSEA's mapping through this incident's failure pattern; not an official determination by the standards bodies.

    Building something similar?

    Describe your design and see every precedent that applies, with safeguards you can hand to your coding agent.

    Analyze your design

    Incidents with the same pattern

    Security advisory2026-10-16

    Software component issue could make the service unavailable

    pupnp is an SDK for development of UPnP device and control point applications. Prior to 2.0.2, rawtoint in upnp/src/genlib/net/http/httpparser.c parses Content-Length with strtol and casts the resulting long to a 32-bit…

    Retry amplification and runaway resource consumptionnvd.nist.gov