[HBASE-9104] added RegionChecker to track when regions go unavailable and back opened

Author: ibra

Summary: added RegionChecker to track when regions go unavailable and back opened

Test Plan:
1) stop/restart some regionserver and if it had regions you will see canges in log (if not, try stop/start/restart some other regionservers)
2) how to see changes in log: you can grep it: cat logfile | grep 'REGION_CHECKER_INFO' to see info

Reviewers: rshroff, aaiyer

Reviewed By: rshroff

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D847584

Task ID: 2130094

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1509360 13f79535-47bb-0310-9956-ffa450edef68
[master]support incremental hfile in task subdir

Author: fan

Summary: support incremental hfile in task subdir

Test Plan: a unit test for creating subdir path

Reviewers: adela, liyintang, manukranthk, aaiyer

Reviewed By: liyintang

CC: hbase-eng@, vinodv

Differential Revision: https://phabricator.fb.com/D896850

Task ID: 2633302

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1509361 13f79535-47bb-0310-9956-ffa450edef68
[HBASE-9105] web ui for regionchecker

Author: ibra

Summary: web ui for region checker

Test Plan: go to http://hbasedev125.ash3.facebook.com:60010/master.jsp and click 'Region Checker'

Reviewers: rshroff, aaiyer

Reviewed By: rshroff

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D880146

Task ID: 2130094

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1509362 13f79535-47bb-0310-9956-ffa450edef68
[master]Make findbugs happy

Author: fan

Summary: Fix some findbugs high priority warnings

Test Plan: take a look at new findbugs report

Reviewers: manukranthk, liyintang

Reviewed By: liyintang

CC: hbase-eng@

Differential Revision: https://phabricator.fb.com/D910084

Task ID: 2624700

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.89-fb@1509363 13f79535-47bb-0310-9956-ffa450edef68