• Facebook queue service: Describes multi-tenant queue service operated by Fb. Handle a trillion events / day. Yikes!
    • Pull based (consumers ask for events on a topic they care about)
    • Global service. Tenants are separated into namespaces
    • Priority queuing
    • Data is split into shards for traffic volume and storage limits
    • Background workers expire events that are aged out or make events that were delayed available when they should be picked up
    • Rate limits are imposed on producers. Rate limits are in place for fairness and to help with capacity planning (Limits are tuned up during peak periods as more processing capacity is brought online)