THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
- Yahoo! Push Notifications: Hedwig is used to serve push notifications to mobile devices.
- Yahoo! Cloud Messaging: Uses BookKeeper to persist messages for guaranteed delivery.
- HubSpot: Uses Bookkeeper in production at the core of its (custom) write-ahead-log service.
- Huawei: Uses BookKeeper as shared storage in Namenode HA.