We reached a significant milestone in HDFS: the Namenode HA branch was merged into the trunk. With this merge, HDFS trunk now supports HOT failover.
Significant enhancements were completed to make HOT Failover work:
- Configuration changes for HA
- Notion of active and standby states were added to the Namenode
- Client-side redirection
- Standby processing journal from Active
- Dual block reports to Active and Standby
We have extensively tested HOT manual failover in our labs over the last few months.…