HBase 2.0 介绍

1 .hbase-2.0.0 Michael Stack Release Manager stack@apache.org 

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3 .Not Yet Released! ● 2.0.0-alpha1 released June 8th, 2017 ○ Preview Release, ‘rough cut’. ● Plan: Alphas => Betas => Final 

4 .Release ● EOY 2017 hbase-2.0.0 EOY 2017 

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6 .Goals: Compatibility ● Double-down on Semantic Versioning, semver ○ Adopted in hbase-1.0.0 ○ MAJOR.MINOR.PATCH[-IDENTIFIER] ■ E.g. 2.0.0-alpha1 

7 .But…. ● Semantic Versioning is about API only ○ What about…. ■ Internal/External Interfaces ● Where is Client Interface when Spark/MapReduce 

8 .API Annotations ● From Hadoop… ○ InterfaceAudience.Public ■ Get/Put/Scan/Connection ○ InterfaceAudience.LimitedPublic ■ Coprocessors, Replication, etc. ○ InterfaceAudience.Private ■ Internal only 

9 .But (Again)... ● What about… ○ Source/Binary compatibility ○ Serializations ■ Wire ■ Formats in HDFS/Zookeeper ○ Dependencies ● See refguide semver section 

10 .But still…. ● Grey areas… ○ Protobufs ■ Protobufs in API ■ Protobufs as Interface (c++/go clients) 

11 .Goal: Rolling Upgrade 1.x to 2.x ● SemVer for DML at least in 2.x ○ No admin of hbase-2.x with hbase-1.x client ○ Coprocessors will need to be upgraded ● hbase-1.x client can work against hbase-2.x cluster ○ Even 1.x Coprocessor Endpoints will work with an hbase-2.x cluster ● No Singularity! No downtime. 

12 .Other Goals ● Scale ○ More Regions, bigger clusters ● Performance ○ Inline read/write but also macro restart, assign, etc. ○ Better resource utilization ■ I/O, RAM ● Fix primary root of operational woes/bugs ○ Master Region Assignment ● Cleanup ○ Spark narrative ○ Interfaces 

13 .2.0.0 

14 .What’s inside hbase-2.0.0? ● Currently >4400 issues resolved ○ ~500 exclusive to 2.0.0 

15 .Inside: Prerequisites ● JDK8 only ● Hadoop-2.7.1 minimum ○ Will work against the coming Hadoop-3.x 

16 .Inside: Main Features ● New Master Core (A.K.A AMv2) ○ Prompt assign of millions of Regions, faster startup, larger scale! ○ Many small Regions instead of a few big ones ○ Promise: new degree of Resilience ● Offheap Read/Write path ○ Less JVM ● Accordion ○ In-memory compaction ○ Less write amplification ● New Async Client ● etc. 

17 .Assignment Manager ● Assignment Manager v1 root of many operational headaches ● Redo based on custom “ProcedureV2”-based State Machine ○ Scale/Performance ○ All Master ops recast as Pv2 procedures ■ E.g. Move is a Procedure composed of an Unassign and Assign subprocedure... ● Operation aggregation ● Entity locking mechanism ○ Isolate operations on tables, regions, servers ○ Parallelization ● One hbase:meta writer, the Master only 

18 .Assignment Manager ● No more intermediate state in ZK ○ At other end of an RPC... ○ Record intent in local Master ops WAL, persisted up in HDFS ○ Only final state published to hbase:meta ● No more HBCK, no more RIT ○ No more distributed state ● Faster Assign ○ PE AMv2 ● Standalone Testable 

19 .Offheap ● Smaller JVM heaps, less copying ○ More accounting! ● Offheap Read Path ○ L1 on Heap for Indexes & Blooms ○ L2 off Heap via BucketCache for Data ■ Big ○ Better latency ■ Cache more ■ Less GC, less erratic ● Offheap Write Path ○ RPC=>HDFS data kept offheap (+Async WAL client) ● Follow-ons: ○ BucketCache always-on 

20 .Accordion ● In-memory LSM ○ In-memory flush from ConcurrentSkipListMap to read-only pipeline of ‘segments’ ■ Memory ‘breathes’ like an accordion’s bellows... ■ Optional in-memory compaction of Segments ● Prune deletes/versions early ● Benefit depends on # of versions ■ Less flushing, write amplification ● Flavors: ○ NONE ○ BASIC (Default) ○ ENHANCED ● Symbiosis w/ Offheaping ○ MemStore SLABs offheap ○ Compact in-memory layout (CellChunkMap) 

21 .Miscellaneous: Complete ● Medium Object Blobs (MOB) ○ Documents, Images, etc. ○ 100k => 10MB ● RegionServer Groups (rsgroups) ○ Coarse Isolation ○ Tables vs RegionServers ● WALs and HFiles in different Filesystems ○ AWS EMR HBase on S3 offering (Amazon S3 Storage Mode) ● New Netty Server/Client chassis ● Filesystem Quotas on Table/Namespace sizes ○ Per Table, per Namespace -- not per User ○ Violation Policy ○ Via Shell 

22 .Miscellaneous: In progress, BLOCKERs ● Spark module ○ Cleanup of our HBase Spark story ● AsyncDFSClient ○ Done but for the testing ● Update+Relocation of core dependencies ○ hbase-thirdparty ■ Guava 0.12 => 0.22 ■ Protobuf 2.5 => 3.3 ■ Netty ○ Etc. 

23 .Miscellaneous: In progress, Nice-to-have ● C++Client ● Backup/Restore ● Hybrid Logical Clock ○ Leap Seconds or Errant clock ○ Overload timestamp to do time and sequence id duty ○ Metadata only for 2.x 

24 .TODOs: BLOCKERs ● Edit of default configs ○ Stale ● API compatibility review ○ And that it wholesome! ● Testing ○ Each new feature/configuration ○ Rolling upgrade ■ Different data provenance/Starting point ● Operation & Scan Timeout Narrative Cleanup ● Sequence Identifier narrative ● Tie-it-off ○ We keep adding to 2.0.0… it’ll never release. 

25 .Moving to 2.x ● API Cleanup ○ Interfaces are returned rather than Implementations ■ TableDescriptor instead of HTableDescriptor, etc. ○ Purged Protobuf and Guava classes from API ■ Purged from CLASSPATH too….(relocated) ● Evangelism: ○ Use shaded hbase-client and hbase-server instead going forward 

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27 .hbase-3.0.0 ● Split hbase:meta ● Refactor filesystem Interface and Implementation ○ Less dependency on HDFS ○ Scale ● HLC everywhere all the time on all tables ● Replication v2 ● Dynamic Online Configuration 

28 .That’s it! ● Thank you to our host Huawei ● Running 2.0 Status: hbase-2.0.0 Status Doc ● References: ○ Matteo Bertozzi on hbase2: https://speakerdeck.com/matteobertozzi/hbase-2-dot-0-sf-meetup-oct-15 ○ Enis Soztutar on hbase2: https://www.slideshare.net/enissoz/meet-hbase-20 ● Images: ● Accordion: https://static.roland.com/assets/images/products/gallery/fr-1x_top_open_gal.jpg ● Version2: http://logofaves.com/wp-content/uploads/2009/06/version_m.jpg?9cf02b ● Long Time: http://www.junodownload.com/products/one-night-only-long-time-coming/1957247-02/ ● Comic: http://4.bp.blogspot.com/-upwza0_lLn4/TmXB4lKkPKI/AAAAAAAAAHY/9lA7VYCmSkI/s1600/heap_0001.jpg ● Stork: http://phicenter.org/wp-content/uploads/2012/08/stork_baby_delivery_720x540.jpg ● Apache Helicopter: https://i.ytimg.com/vi/SQp-3fUBefA/maxresdefault.jpg ● Goals: http://az616578.vo.msecnd.net/files/2016/02/29/6359235488335557721545302495_GOALS600.png