Branch for automatic NN failover support (HDFS-3042)


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Merge trunk into HDFS-3042 branch


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Amend HADOOP-8212 (Improve ActiveStandbyElector's behavior when session expires)

Amendment patch incorporates following feedback from Bikas Saha:
- adds a new functional test for session expiration while in the standby state
- adds a safety check in the StatCallback for session expiration
- improves some comments


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HADOOP-8220. ZKFailoverController doesn't handle failure to become active correctly. Contributed by Todd Lipcon.

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HADOOP-8228. Auto HA: Refactor tests and add stress tests. Contributed by Todd Lipcon.

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Merge trunk into auto-failover branch


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HDFS-2185. HDFS portion of ZK-based FailoverController. Contributed by Todd Lipcon.

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Merge trunk into auto-failover branch


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HADOOP-8215. Security support for ZK Failover controller. Contributed by Todd Lipcon.

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HADOOP-8245. Fix flakiness in TestZKFailoverController. Contributed by Todd Lipcon.

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Merge trunk into auto-HA branch

Resolved some trivial conflicts in NNHAServiceTarget


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HDFS-3200. Scope all ZKFC configurations by nameservice. Contributed by Todd Lipcon.

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Merge trunk into auto-failover branch.

Addressed two semantic conflicts after the commit of HADOOP-8077 -- test code was referencing the old constant for the fencing methods config key.


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Fix trivial mistake in test code in previous merge - tests were failing due to misuse of NodeFencer.create


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HADOOP-8257. TestZKFailoverControllerStress occasionally fails with Mockito error. Contributed by Todd Lipcon.

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HDFS-3223. add zkfc to hadoop-daemon.sh script. Contributed by Todd Lipcon.

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HADOOP-8260. Replace ClientBaseWithFixes with our own modified copy of the class. Contributed by Todd Lipcon.

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Merge trunk into auto-failover branch


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HADOOP-8246. Auto-HA: automatically scope znode by nameservice ID. Contributed by Todd Lipcon.

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HADOOP-8247. Add a config to enable auto-HA, which disables manual FailoverController. Contributed by Todd Lipcon.

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