[HBASE-15292] Refined ZooKeeperWatcher to prevent ZooKeeper's callback while construction

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.3.0, 0.98.20, 2.0.0
• Component/s: Zookeeper
• Hadoop Flags: Reviewed
• Assignee: Hiroshi Ikeda
• Reporter: Hiroshi Ikeda
• Created: 19/Feb/16 10:41
• Updated: 09/Nov/17 00:51
• Resolved: 05/May/16 23:08

Description

The existing code is not just messy but also contains a subtle bug of visibility due to missing synchronization between threads.

The root of the evil is that ZooKeeper uses a silly anti-pattern, starting a thread within its constructor, and in practice all the developers are not allowed to use ZooKeeper correctly without tedious code.

Sub-Tasks

• Typo in javadoc of InstancePending: Resolved