[HBASE-14089] Remove unnecessary draw of system entropy from RecoverableZooKeeper

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.98.14, 1.0.2, 1.2.0, 1.1.2, 1.3.0, 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Andrew Kyle Purtell
• Reporter: Andrew Kyle Purtell
• Created: 15/Jul/15 16:52
• Updated: 04/Dec/15 19:41
• Resolved: 16/Jul/15 01:54

Description

I had a look at instances where we use SecureRandom, which could block if insufficient entropy, in the 0.98 and master branch code. (Random in contrast is a PRNG seeded by System#nanoTime, it doesn't draw from system entropy.) Most uses are in encryption related code, our native encryption and SSL, but we do also use SecureRandom for salting znode metadata in RecoverableZooKeeper#appendMetadata, which is called whenever we do setData. Conceivably we could block unexpectedly when constructing data to write out to a znode if entropy gets too low until more is available.