[RATIS-320] Fencing support for Logs

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Josh Elser
• Created: 14/Sep/18 15:58
• Updated: 14/Sep/18 15:58

Description

HBase has a use-case where, in certain situations, we need to prevent a RegionServer from continuing to write more edits into a Log. Specifically, if a RS loses its ZooKeeper lock, we want to prevent that RS from being allowed to write anything more into any WALs.

For the "current" Log, this is easy for us to handle as we can call LogService#closeLog(LogName) to prevent anyone from writing from writing to that LogStream. However, we don't have any mechanism to prevent that RS from creating a new Log and starting to write to it.

We need to come up with a solution inside of the LogService which can be used to prevent a specific client from creating new Logs.