HBase Change Log

Release 0.96.0 - Unreleased
265+ issues resolved/closed.  See http://goo.gl/4zegPr for the list.

Release 0.95.1 -- Release Candidate, May 27th, 2013 
215 issues resolved.  See
https://issues.apache.org/jira/issues/?jql=project%20%3D%20HBASE%20AND%20fixVersion%20%3D%20%220.95.1%22%20AND%20status%20%3D%20Resolved%20ORDER%20BY%20type%20DESC

Test

HBASE-8071 - TestRestoreFlushSnapshotFromClient fails intermittently in trunk builds
HBASE-8520 - TestIOFencing fails intermittently due to compaction kicking in too soon
HBASE-8535 - Test for zk leak does not account for unsynchronized access to zk watcher
HBASE-8333 - TestTableLockManager#testDelete may occasionally fail due to lack of synchronization between test and handler thread
HBASE-8308 - Lower the number of expected regions in TestTableLockManager#testTableReadLock
HBASE-8575 - TestDistributedLogSplitting#testMarkRegionsRecoveringInZK fails intermittently due to lack of online region

Task

HBASE-7936 - Undo prefix-tree module as dependency for mapreduce and for DataBlockEncoding
HBASE-8045 - Fix .META. migration after HBASE-3171
HBASE-7897 - Add support for tags to Cell Interface
HBASE-7997 - One last set of class moves before 0.95 goes out
HBASE-7704 - migration tool that checks presence of HFile V1 files
HBASE-8450 - "Update hbase-default.xml and general recommendations to better suit current hw, h2, experience, etc."
HBASE-8395 - Remove TestFromClientSide.testPoolBehavior
HBASE-8319 - hbase-it tests are run when you ask to run all tests -- it should be that you have to ask explicitly to run them
HBASE-8296 - Add svn ignores to hbase-assembly
HBASE-8574 - Add how to rename a table in the docbook
HBASE-6365 - Deprecate classes that depend on (old) metrics framework

Sub-task

HBASE-7995 - HBASE-8084 Export$Exporter could be replaced with IdentityTableMapper
HBASE-7942 - HBASE-4755 Make use of the plumbing in HBASE-7932 to provide location hints when region files are created
HBASE-7932 - HBASE-4755 Do the necessary plumbing for the region locations in META table and send the info to the RegionServers
HBASE-7836 - "HBASE-7006 Create a new ""replay"" command so that recovered edits won't mess up normal coprocessing & metrics"
HBASE-7835 - HBASE-7006 Implementation of the log splitting without creating intermediate files
HBASE-7837 - HBASE-7006 Add new metrics to better monitor recovery process
HBASE-7636 - HBASE-6891 TestDistributedLogSplitting#testThreeRSAbort fails against hadoop 2.0
HBASE-7606 - HBASE-6891 TestJoinedScanners fails in trunk build on hadoop 2.0
HBASE-7605 - HBASE-6891 TestMiniClusterLoadSequential fails in trunk build on hadoop 2
HBASE-7413 - HBASE-5305 Convert WAL to pb
HBASE-7239 - HBASE-7215 Verify protobuf serialization is correctly chunking upon read to avoid direct memory OOMs
HBASE-8024 - HBASE-7949 Make Store flush algorithm pluggable
HBASE-8477 - HBASE-6891 [hadoop2] TestTableInputFormatScan* fails intermittently with PrivilegedActionException
HBASE-8478 - HBASE-6891 HBASE-2231 breaks TestHRegion#testRecoveredEditsReplayCompaction under hadoop2 profile
HBASE-8469 - HBASE-6891 [hadoop2] Several tests break because of HDFS-4305
HBASE-8424 - HBASE-8427 IntegrationTestImportTsv missing Apache License
HBASE-8429 - HBASE-8427 TestMetricsWALSourceImpl from hbase-hadoop2-compat module missing Apache license.
HBASE-8392 - HBASE-6891 TestMetricMBeanBase#testGetAttribute is flakey under hadoop2 profile
HBASE-8497 - HBASE-5305 Protobuf WAL also needs a trailer
HBASE-8528 - HBASE-6891 [hadoop2] TestMultiTableInputFormat always fails on hadoop with YARN-129 applied
HBASE-8347 - HBASE-6891 TestSecureLoadInc* tests hang repeatedly getting UnsupportedOperationException in hadoop2 profile
HBASE-8349 - HBASE-6891 TestLogRolling#TestLogRollOnDatanodeDeath hangs under hadoop2 profile
HBASE-8343 - HBASE-6891 TestMultiTableInputFormat hung in HBase-TRUNK-on-Hadoop-2.0.0 build #498
HBASE-8342 - HBASE-6891 TestTableInputFormatScan#testScanFromConfiguration fails on hadoop2 profile
HBASE-8324 - HBASE-6891 TestHFileOutputFormat.testMRIncremental* fails against hadoop2 profile
HBASE-4915 - HBASE-4907 TestHFilePerformance
HBASE-3967 - HBASE-4907 Support deletes in HFileOutputFormat based bulk import mechanism
HBASE-5995 - HBASE-6891 Fix and reenable TestLogRolling.testLogRollOnPipelineRestart
HBASE-5746 - HBASE-5720 HFileDataBlockEncoderImpl uses wrong header size when reading HFiles with no checksums (0.96)
HBASE-2299 - HBASE-1961 [EC2] mapreduce fixups for PE
HBASE-6330 - HBASE-6891 TestImportExport has been failing against hadoop 0.23/2.0 profile
HBASE-8583 - HBASE-8551 Create a new IntegrationTestBigLinkedListWithChaosMonkey

New Feature

HBASE-7828 - "Expose HBase Scan object's ""batch"" property for intra-row batching in Thrift API"
HBASE-7842 - Add compaction policy that explores more storefile groups
HBASE-7244 - "Provide a command or argument to startup, that formats znodes if provided"
HBASE-7006 - [MTTR] Improve Region Server Recovery Time - Distributed Log Replay
HBASE-8372 - Provide mutability to CompoundConfiguration
HBASE-8415 - DisabledRegionSplitPolicy
HBASE-5525 - Truncate and preserve region boundaries option

Improvement

HBASE-7923 - force unassign can confirm region online on any RS to get rid of double assignments.
HBASE-7567 - [replication] Create an interface for replication peers
HBASE-7568 - [replication] Create an interface for replication queues
HBASE-7745 - Import uses System.out.println instead of logging
HBASE-7649 - client retry timeout doesn't need to do x2 fallback when going to different server
HBASE-7434 - "Use generics appropriately in RPCEngine and reduce casts, with fixing a related bug of breaking thread-safety in HConnectionManager"
HBASE-7247 - Assignment performances decreased by 50% because of regionserver.OpenRegionHandler#tickleOpening
HBASE-6870 - HTable#coprocessorExec always scan the whole table
HBASE-6966 - """Compressed RPCs for HBase"" (HBASE-5355) port to trunk"
HBASE-8485 - Retry to open a HLog on more exceptions
HBASE-8471 - "Server-side, remove convertion from pb type to client type before we call method"
HBASE-8405 - Add more custom options to how ClusterManager runs commands
HBASE-8383 - Support lib/*jar inside coprocessor jar
HBASE-8367 - LoadIncrementalHFiles does not return an error code nor throw Exception when failures occur due to timeouts
HBASE-8461 - Provide the ability to delete multiple snapshots through single command
HBASE-8470 - Data file used by TestReference should be excluded from Apache Rat check
HBASE-8301 - Document for hbase.rpc.timeout
HBASE-8284 - Allow String Offset(s) in ColumnPaginationFilter for bookmark based pagination
HBASE-8272 - make compaction checker frequency configurable per table/cf
HBASE-8345 - Add all available resources in o.a.h.h.rest.RootResource and VersionResource to o.a.h.h.rest.client.RemoteAdmin
HBASE-8339 - Make sure the StochasticLoadBalancer doesn't run a cost function when not needed
HBASE-8240 - CompoundConfiguration should implement Iterable
HBASE-8235 - Adding inmemory CF attribute to LoadTest and PerformanceEvaluation tool
HBASE-8205 - HBCK support for table locks
HBASE-4906 - [book] book.xml added MapReduce to RDBMS example
HBASE-4732 - "[book] book.xml, added link to MapReduce tutorial"
HBASE-4316 - book.xml - overhauled MapReduce section to provide more examples
HBASE-8420 - Port HBASE-6874 Implement prefetching for scanners from 0.89-fb
HBASE-8573 - Store last flushed sequence id for each store of region for Distributed Log Replay
HBASE-5930 - Limits the amount of time an edit can live in the memstore.
HBASE-5577 - improve 'patch submission' section in HBase book
HBASE-2231 - Compaction events should be written to HLog
HBASE-1762 - Remove concept of ZooKeeper from HConnection interface
HBASE-1548 - give a time range in MapReduce
HBASE-6294 - Detect leftover data in ZK after a user delete all its HBase data
HBASE-8613 - Improve logging when BindException is received at startup time.
HBASE-8618 - Master is providing dead RegionServer ServerName's to the balancer

Bug

HBASE-8385 - [SNAPSHOTS]: Restore fails to restore snapshot of a deleted table
HBASE-7871 - HBase can be stuck when closing regions concurrently
HBASE-7838 - HBase regionserver never stops when running `hbase-daemon.sh stop regionserver`
HBASE-7686 - TestSplitTransactionOnCluster fails occasionally in trunk builds
HBASE-7726 - Family Dir is not removed using modifyTable()
HBASE-7380 - "[replication] When transferring queues, check if the peer still exists before copying the znodes"
HBASE-7192 - Move TestHBase7051.java into TestAtomicOperation.java
HBASE-7255 - KV size metric went missing from StoreScanner.
HBASE-7167 - Thrift's deleteMultiple() raises exception instead of returning list of failed deletes
HBASE-7135 - Serializing hfileBlcok is incorrect for SlabCache
HBASE-7014 - cleanup 4 minor findbug warings
HBASE-7122 - Proper warning message when opening a log file with no entries (idle cluster)
HBASE-7921 - TestHFileBlock.testGzipCompression should ignore the block checksum
HBASE-6975 - HBASE-6940 enabling GC needs refinement
HBASE-8451 - MetricsMBeanBase has concurrency issues in init
HBASE-8396 - balancerSwitch making two zookeeper calls everytime.
HBASE-8483 - HConnectionManager can leak ZooKeeper connections when using deleteStaleConnection
HBASE-8472 - mvn -Dhadoop.profile=2.0 -Dhadoop-two.version=2.0.5-SNAPSHOT fails because of Undef Class error wrt o.a.h.IdGenerator
HBASE-8426 - "Opening a region failed on ""Metrics source RegionServer,sub=Regions already exists!"""
HBASE-8425 - Per-region memstore size is missing in the new RS web UI
HBASE-8406 - Fix rat check and rat warning in trunk
HBASE-8407 - Remove Async HBase from 0.95 and trunk.
HBASE-8374 - NullPointerException when launching the balancer due to unknown region location
HBASE-8482 - TestHBaseFsck#testCheckTableLocks broke; java.lang.AssertionError: expected:<[]> but was:<[EXPIRED_TABLE_LOCK]>
HBASE-8468 - IntegrationTestImportTsv fails on a cluster
HBASE-8460 - [replication] Fix the three TODOs in TestReplicationStateBasic.testReplicationQueues
HBASE-8430 - Cell decoder/scanner/etc. should not hide exceptions
HBASE-8431 - Fix missing headers
HBASE-8428 - Tighten up IntegrationTestsDriver filter
HBASE-8422 - Master won't go down. Stuck waiting on .META. to come on line.
HBASE-8421 - hbase-0.95.0 tgz does not include lib/junit*.jar
HBASE-8404 - Extra commas in LruBlockCache.logStats
HBASE-8379 - bin/graceful_stop.sh does not return the balancer to original state
HBASE-8360 - In HBaseClient#cancelConnections we should close fully the connection
HBASE-8474 - there are dups in hadoop2 pom
HBASE-8466 - Netty messages in the logs
HBASE-8464 - FastDiffEncoder - valueOffset calculation is incorrect
HBASE-8456 - HBase Windows scripts fail when there's a blank space in JAVA_HOME
HBASE-8437 - Clean up tmp coprocessor jars
HBASE-8393 - Testcase TestHeapSize#testMutations is wrong
HBASE-8391 - StochasticLoadBalancer doesn't call needsBalance
HBASE-8380 - NPE in HBaseClient$Connection.readResponse
HBASE-8377 - IntegrationTestBigLinkedList calculates wrap for linked list size incorrectly
HBASE-8359 - Too much logs on HConnectionManager
HBASE-8600 - Bunch of log lines from QosFunction: Marking normal priority after
HBASE-8596 - "[docs] Add docs about Region server ""draining"" mode"
HBASE-8606 - Meta scanner is not closed
HBASE-8602 - Ugly stack trace just because regionserver comes up before master....
HBASE-8547 - Fix java.lang.RuntimeException: Cached an already cached block
HBASE-8540 - SnapshotFileCache logs too many times if snapshot dir doesn't exists
HBASE-8539 - Double(or tripple ...) ZooKeeper listeners of the same type when Master recovers from ZK SessionExpiredException
HBASE-8537 - Dead region server pulled in from ZK
HBASE-8536 - Possible NullPointerException in ZKInterProcessLockBase#reapExpiredLocks
HBASE-8530 - Refine error message from ExportSnapshot when there is leftover snapshot in target cluster
HBASE-8525 - Use sleep multilier when choosing sinks in ReplicationSource
HBASE-8510 - HBASE-8469 added a hdfs-site.xml file for tests but it gets included in the test jar
HBASE-8507 - HLog tool documentation should be updated to use FSHLog for trunk and 0.95.
HBASE-8505 - References to split daughters should not be deleted separately from parent META entry
HBASE-8545 - Meta stuck in transition when it is assigned to a just restarted dead region sever
HBASE-8531 - TestZooKeeper fails in trunk/0.95 builds
HBASE-8522 - "Archived hfiles and old hlogs may be deleted immediately by HFileCleaner, LogCleaner in HMaster"
HBASE-8519 - Backup master will never come up if primary master dies during initialization
HBASE-8514 - There's an orig file in 0.95
HBASE-8509 - ZKUtil#createWithParents won't set data during znode creation when parent folder doesn't exit
HBASE-8506 - Remove unused/dead classes
HBASE-8355 - BaseRegionObserver#pre(Compact|Flush|Store)ScannerOpen returns null
HBASE-8327 - Consolidate class loaders
HBASE-8321 - Log split worker should heartbeat to avoid timeout when the hlog is under recovery
HBASE-8300 - TestSplitTransaction fails to delete files due to open handles left when region is split
HBASE-8299 - ExploringCompactionPolicy can get stuck in rare cases.
HBASE-8290 - TestHTableMultiplexer is flaky
HBASE-8282 - User triggered flushes does not allow compaction to get triggered even if compaction criteria is met
HBASE-8279 - Performance Evaluation does not consider the args passed in case of more than one client
HBASE-8334 - Enable essential column family support by default
HBASE-8312 - TestCompactionState - still timeouting
HBASE-8305 - Too much logs in the some tests
HBASE-8295 - TestMasterFailover.testMasterFailoverWithMockedRITOnDeadRS is flaky.
HBASE-8293 - Move BigDecimalColumnInterpreter into hbase-client
HBASE-8346 - Prefetching .META. rows in case only when useCache is set to true
HBASE-8341 - RestoreSnapshotHandler.prepare() is not called by SnapshotManager and TakeSnapshotHandler should first acquire the table lock
HBASE-8336 - PooledHTable may be returned multiple times to the same pool
HBASE-8317 - Seek returns wrong result with PREFIX_TREE Encoding
HBASE-8314 - HLogSplitter can retry to open a 0-length hlog file
HBASE-8289 - TestThreads#testSleepWithoutInterrupt should not expect a bounded wait time
HBASE-8588 - [Documentation]: Add information about adding REST and Thrift API kerberos principals to HBase ACL table
HBASE-8581 - rpc refactor dropped passing the operation timeout through to the rpcclient
HBASE-8577 - TestZooKeeper#testLogSplittingAfterMasterRecoveryDueToZKExpiry failed intermittently
HBASE-8568 - Test case TestDistributedLogSplitting#testWorkerAbort failed intermittently
HBASE-8567 - TestDistributedLogSplitting#testLogReplayForDisablingTable fails on hadoop 2.0
HBASE-8555 - FilterList correctness may be affected by random ordering of sub-filter(list)
HBASE-8582 - Possible NullPointerException in ZKInterProcessLockBase#visitLocks
HBASE-8564 - TestMetricsRegionServer depends on test order
HBASE-8560 - "TestMasterShutdown failing in trunk 0.95/trunk -- ""Unable to get data of znode /hbase/meta-region-server because node does not exist (not an error)"""
HBASE-8267 - Add some resources checker for tests
HBASE-8252 - Regions by Region Server table in Master's table view needs styling
HBASE-8254 - Add lz4 to test compression util usage string
HBASE-8248 - HConnectionManager moved region tracking can cause the region server to redirect to itself; load balancer uses incorrect servername compare
HBASE-8239 - ChaosMonkey action for root is irrelevant
HBASE-8263 - Master LogSplitting metrics update wrong counters
HBASE-8241 - Fix the bad dependency on netty from HDFS
HBASE-8214 - "Remove proxy and engine, rely directly on pb generated Service"
HBASE-8204 - Don't use hdfs append during lease recovery
HBASE-8165 - Update our protobuf to 2.5 from 2.4.1
HBASE-8133 - avoid assign for disabling table regions(OPENING/PENDING_OPEN) in SSH
HBASE-8119 - Optimize StochasticLoadBalancer
HBASE-4885 - Building against Hadoop 0.23 uses out-of-date MapReduce artifacts
HBASE-4814 - Starting an online alter when regions are splitting can leave their daughters unaltered
HBASE-8449 - Refactor recoverLease retries and pauses informed by findings over in hbase-8389
HBASE-8570 - CompactSplitThread logs a CompactSplitThread$CompactionRunner but it does not have a toString
HBASE-8366 - HBaseServer logs the full query.
HBASE-8597 - compaction record (probably) can block WAL cleanup forever if region is closed without edits
HBASE-3937 - Region PENDING-OPEN timeout with un-expected ZK node state leads to an endless loop
HBASE-5946 - Thrift Filter Language documentation is inconsistent
HBASE-5835 - [hbck] Catch and handle NotServingRegionException when close region attempt fails
HBASE-5472 - LoadIncrementalHFiles loops forever if the target table misses a CF
HBASE-3578 - TableInputFormat does not setup the configuration for HBase mapreduce jobs correctly
HBASE-1783 - Fix mapreduce package javadoc.
HBASE-1653 - new o.a.h.h.mapreduce package is incompletely ported to o.a.h.mapreduce
HBASE-1212 - merge tool expects regions all have different sequence ids
HBASE-8621 - More log edits; we log too much
HBASE-8622 - Remove ' You are currently running the HMaster without HDFS append support enabled. This may result in data loss. Please see the HBase wiki for details. ' from UI
HBASE-8517 - Stochastic Loadbalancer isn't finding steady state on real clusters


Release 0.95.0 -- Release Candidate, April 1st, 2013
From https://issues.apache.org/jira/secure/ReleaseNote.jspa?projectId=12310753&version=12324094

Sub-task

[HBASE-2611] - Handle RS that fails while processing the failure of another one
[HBASE-3776] - Add Bloom Filter Support to HFileOutputFormat
[HBASE-3967] - Support deletes in HFileOutputFormat based bulk import mechanism
[HBASE-4285] - partitions file created in user's home directory by importtsv
[HBASE-4624] - Remove and convert @deprecated RemoteExceptionHandler.decodeRemoteException calls
[HBASE-4625] - Convert @deprecated HBaseTestCase tests in 0.90 into JUnit4 style tests in 0.92 and TRUNK
[HBASE-4909] - Detailed Block Cache Metrics
[HBASE-4910] - thrift scannerstopwithfilter not honoring stop row
[HBASE-4913] - Per-CF compaction Via the Shell
[HBASE-4914] - Enhance MapReduce TableInputFormat to Support N-mappers per Region
[HBASE-4915] - TestHFilePerformance
[HBASE-4916] - LoadTest MR Job
[HBASE-4917] - CRUD Verify Utility
[HBASE-4990] - Document secure HBase setup
[HBASE-5133] - Support zookeeper cluster key related parameters for LoadTestTool
[HBASE-5151] - Rename "hbase.skip.errors" in HRegion as it is too general-sounding.
[HBASE-5164] - Better HTable resource consumption in CoprocessorHost
[HBASE-5342] - Grant/Revoke global permissions
[HBASE-5372] - Table mutation operations should check table level rights, not global rights
[HBASE-5385] - Delete table/column should delete stored permissions on -acl- table
[HBASE-5414] - Assign different memstoreTS to different KV's in the same WALEdit during replay
[HBASE-5418] - use different memstoreTS for different operations in the same RowMutation.
[HBASE-5444] - Add PB-based calls to HMasterRegionInterface
[HBASE-5445] - Add PB-based calls to HMasterInterface
[HBASE-5446] - Replace serialization for client-facing ZK data with PBs
[HBASE-5447] - Support for custom filters with PB-based RPC
[HBASE-5448] - Support for dynamic coprocessor endpoints with PB-based RPC
[HBASE-5449] - Support for wire-compatible security functionality
[HBASE-5451] - Switch RPC call envelope/headers to PBs
[HBASE-5453] - Switch on-disk formats (reference files, HFile meta fields, etc) to PB
[HBASE-5523] - Fix Delete Timerange logic for KEEP_DELETED_CELLS
[HBASE-5619] - Create PB protocols for HRegionInterface
[HBASE-5620] - Convert the client protocol of HRegionInterface to PB
[HBASE-5621] - Convert admin protocol of HRegionInterface to PB
[HBASE-5638] - Backport to 0.90 and 0.92 - NPE reading ZK config in HBase
[HBASE-5641] - decayingSampleTick1 prevents HBase from shutting down.
[HBASE-5642] - [findbugs] Exclude Thrift and Protobuf warnings
[HBASE-5644] - [findbugs] Fix null pointer warnings.
[HBASE-5645] - [findbugs] Fix correctness warnings
[HBASE-5652] - [findbugs] Fix lock release on all paths
[HBASE-5653] - [findbugs] fix perf warnings
[HBASE-5654] - [findbugs] Address dodgy bugs
[HBASE-5659] - TestAtomicOperation.testMultiRowMutationMultiThreads is still failing occasionally
[HBASE-5685] - [findbugs] Exclude Protobuf warnings from wire compat patches.
[HBASE-5705] - Introduce Protocol Buffer RPC engine
[HBASE-5732] - Remove the SecureRPCEngine and merge the security-related logic in the core engine
[HBASE-5746] - HFileDataBlockEncoderImpl uses wrong header size when reading HFiles with no checksums (0.96)
[HBASE-5785] - Adding unit tests for protbuf utils introduced for HRegionInterface pb conversion
[HBASE-5793] - TestHBaseFsck#TestNoHdfsTable test hangs after client retries increased
[HBASE-5937] - Refactor HLog into an interface.
[HBASE-5995] - Fix and reenable TestLogRolling.testLogRollOnPipelineRestart
[HBASE-6052] - Convert .META. and -ROOT- content to pb
[HBASE-6061] - Fix ACL "Admin" Table inconsistent permission check
[HBASE-6066] - some low hanging read path improvement ideas
[HBASE-6092] - Authorize flush, split, compact operations in AccessController
[HBASE-6157] - Revoke of Global permission is not taking effect without restart.
[HBASE-6180] - [brainstorm] Timestamp based snapshots in HBase 0.96
[HBASE-6188] - Remove the concept of table owner
[HBASE-6202] - Medium tests fail with jdk1.7
[HBASE-6203] - Create hbase-it module
[HBASE-6206] - Large tests fail with jdk1.7
[HBASE-6209] - ACL Corrections for AccessControllerProtocol apis
[HBASE-6224] - add Pre and Post coprocessor hooks for BulkLoad
[HBASE-6230] - [brainstorm] "Restore" snapshots for HBase 0.96
[HBASE-6238] - Grant on META not taking effect
[HBASE-6241] - HBaseCluster interface for interacting with the cluster from system tests
[HBASE-6252] - TABLE ADMIN should be allowed to relocate regions
[HBASE-6253] - Do not allow user to disable or drop ACL table
[HBASE-6282] - The introspection, etc. of objects in the RPC has to be handled for PB objects
[HBASE-6292] - Compact can skip the security access control
[HBASE-6302] - Document how to run integration tests
[HBASE-6307] - Fix hbase unit tests running on hadoop 2.0
[HBASE-6330] - TestImportExport has been failing against hadoop 0.23/2.0 profile [Part2]
[HBASE-6353] - Snapshots shell
[HBASE-6355] - Allow HBase to compile against JDK7
[HBASE-6405] - Create Hadoop compatibilty modules and Metrics2 implementation of replication metrics
[HBASE-6408] - Naming and documenting of the hadoop-metrics2.properties file
[HBASE-6409] - Create histogram class for metrics 2
[HBASE-6410] - Move RegionServer Metrics to metrics2
[HBASE-6411] - Move Master Metrics to metrics 2
[HBASE-6412] - Move external servers to metrics2 (thrift,thrift2,rest)
[HBASE-6414] - Remove the WritableRpcEngine & associated Invocation classes
[HBASE-6496] - Example ZK based scan policy
[HBASE-6501] - Integrate with unit-testing tools of hadoop's metrics2 framework
[HBASE-6524] - Hooks for hbase tracing
[HBASE-6568] - Extract daemon thread factory from HTable into its own class
[HBASE-6569] - Extract HStore interface from Store
[HBASE-6570] - Fix hfile/log cleaning delegate method naming
[HBASE-6571] - Generic multi-thread/cross-process error handling framework
[HBASE-6598] - Combine Master Metrics into a single class.
[HBASE-6601] - TestImportExport on Hadoop 2 must copy YARN configuration vars
[HBASE-6610] - HFileLink: Hardlink alternative for snapshot restore
[HBASE-6614] - General cleanup/optimizations of the protobuf RPC engine & associated RPC code
[HBASE-6630] - Port HBASE-6590 to trunk : Assign sequence number to bulk loaded files
[HBASE-6717] - Remove hadoop-metrics.properties when everything has moved over.
[HBASE-6718] - Clean up BaseMetricsSourceImpl
[HBASE-6765] - 'Take a snapshot' interface
[HBASE-6777] - Snapshot Restore interface
[HBASE-6785] - Convert AggregateProtocol to protobuf defined coprocessor service
[HBASE-6786] - Convert MultiRowMutationProtocol to protocol buffer service
[HBASE-6787] - Convert RowProcessorProtocol to protocol buffer service
[HBASE-6788] - Convert AuthenticationProtocol to protocol buffer service
[HBASE-6789] - Convert test CoprocessorProtocol implementations to protocol buffer services
[HBASE-6802] - Export Snapshot
[HBASE-6809] - Deprecate Old metrics classes.
[HBASE-6815] - [WINDOWS] Provide hbase scripts in order to start HBASE on Windows in a single user mode
[HBASE-6816] - [WINDOWS] line endings on checkout for .sh files
[HBASE-6825] - [WINDOWS] Java NIO socket channels does not work with Windows ipv6
[HBASE-6863] - Offline snapshots
[HBASE-6864
...