+1 (non binding) Regards, Uma
On 3/3/16, 5:29 PM, "Poorna Chandra" <poo...@apache.org> wrote: >Hi All, > >Tephra proposal was sent out for discussion last week. The proposal is >available at https://wiki.apache.org/incubator/TephraProposal > >Please vote to accept Tephra into the Apache Incubator. The vote will be >open for the next 72 hours. > >[ ] +1 Accept Tephra as an Apache Incubator podling. >[ ] +0 Abstain. >[ ] -1 Don¹t accept Tephra as an Apache Incubator podling because ... > >Thanks, >Poorna. > >------ > >= Abstract = > >Tephra is a system for providing globally consistent transactions on >top of Apache HBase and other storage engines. > >= Proposal = > >Tephra is a transaction engine for distributed data stores like Apache >HBase. >It provides ACID semantics for concurrent data operations that span over >region >boundaries in HBase using Optimistic Concurrency Control. > >= Background = > >HBase provides strong consistency with row- or region-level ACID >operations. However, it sacrifices cross-region and cross-table >consistency in favor of scalability. This trade-off requires application >developers to handle the complexity of ensuring consistency when their >modifications span region boundaries. By providing support for global >transactions that span regions, tables, or multiple RPCs, >Tephra simplifies application development on top of HBase, without a >significant impact on performance or scalability for many workloads. > >Tephra leverages HBase¹s native data versioning to provide multi-versioned >concurrency control (MVCC) for transactional reads and writes. >With MVCC capability, each transaction sees its own consistent ³snapshot² >of >data, providing snapshot isolation of concurrent transactions. >MVCC along with conflict detection and handling enables Optimistic >Concurrency >Control. > >Tephra consists of three main components: > * Transaction Server maintains global view of transaction state, >assigns > new transaction IDs and performs conflict detection; > * Transaction Client coordinates start, commit, and rollback of >transactions; and > * Transaction Processor Coprocessor applies filtering to the data read >(based > on a given transaction¹s state) and cleans up any data from old > (no longer visible) transactions. > >Although Tephra only supports HBase now, it can be extended to support >transactions on any store that has multi-versioning and rollback >support. The transactions >can span over multiple stores and storage paradigms. > >= Rationale = > >Tephra has simple abstractions which can be used by an application to >add transaction support over HBase. By abstracting away transaction >handling using Tephra, the application is freed of >transaction logic, and the application developer can focus on the use >case. >Also, Tephra can be extended to support transactions on data sources other >than HBase. > >By making Tephra an Apache open source project, we believe that there will >be wider adoption and more opportunities for Tephra to be integrated >into other Apache projects. > >= Current Status = > >Tephra was built at Cask Data Inc. initially as part of >open-source framework Cask Data Application Platform (CDAP) >[[http://cdap.io/]]. >It was later converted into an independent open source project with >Apache 2.0 License [[https://github.com/caskdata/tephra]]. > >Tephra is used in CDAP as the transaction engine. As part of CDAP, Tephra >has been deployed at multiple companies. > >Apache Phoenix is using Tephra as transaction engine in the next release. > >== Meritocracy == > >Our intent with this incubator proposal is to start building a diverse >developer community around Tephra following the Apache meritocracy model. >Since Tephra was initially developed in early 2013, we have had fast >adoption and contributions within Cask Data. We are looking forward to >new contributors. We wish to build a community based on Apache's >meritocracy principles, working with those who contribute significantly to >the project and welcoming them to be committers both during the incubation >process and beyond. > >== Community == > >Core developers of Tephra are at Cask Data. Recently the developer >community >has expanded to include folks from Apache Phoenix. We hope to extend our >contributor base significantly and we will invite all who are interested >in working on distributed transaction engine. > >== Core Developers == > >A few engineers from Cask Data and outside have developed Tephra: >Andreas Neumann, Terence Yim, Gary Helmling, Andrew Purtell and >Poorna Chandra. > > >== Alignment == > >The ASF is the natural choice to host the Tephra project as its goal of >encouraging community-driven open source projects fits with our vision for >Tephra. > >Additionally, many other projects with which we are familiar and expect >Tephra to integrate with, such as Phoenix, Zookeeper, HDFS, log4j, and >others >mentioned in the External Dependencies section are Apache projects, and >Tephra will benefit by close proximity to them. > >= Known Risks = > >== Orphaned Products == > >There is very little risk of Tephra being orphaned, as it is a key part of >Cask Data¹s products. The core Tephra developers plan to continue to work >on Tephra, and Cask Data has funding in place to support their efforts >going forward. >Also with Phoenix using Tephra for transactions, Phoenix developers are >keen on contributing to Tephra. > > >== Inexperience with Open Source == > >Several of the core developers have experience with open source >development. Andreas Neumann is an Apache committer for Oozie and Twill. >Terence Yim is an Apache committer for Helix and Twill. Poorna Chandra >is an Apache committer for Twill. Gary Helmling is a committer for >Apache Twill and a committer and PMC member for Apache HBase. >James Taylor is PMC chair for Apache Phoenix, PMC member of Apache >Calcite, >and an IPMC member. > >== Homogeneous Developers == > >The current core developers are all Cask Data employees. However, we >intend to establish a developer community that includes independent and >corporate contributors. We are encouraging new contributors via our >mailing >lists, public presentations, and personal contacts, and we will continue >to >do so. > >Apache Phoenix developers have already contributed several patches to >Tephra, >and have expressed interest in becoming long term contributors. > >== Reliance on Salaried Developers == > >Currently, these developers are paid to work on Tephra. Once the project >has >built a community, we expect to attract committers, developers and >community >other than the current core developers. However, because Cask Data >products use Tephra internally, the reliance on salaried developers is >unlikely to change, at least in the near term. > >== Relationships with Other Apache Products == > >Tephra is deeply integrated with Apache projects. Tephra provides >transactions >over Apache HBase, and uses Apache Twill and Apache Zookeeper for >coordination. >A number of other Apache projects are Tephra dependencies, and are >listed in the External Dependencies section. > >In addition, Apache Phoenix is using Tephra as the transaction engine. > >== An Excessive Fascination with the Apache Brand == > >While we respect the reputation of the Apache brand and have no doubt that >it will attract contributors and users, our interest is primarily to give >Tephra a solid home as an open source project following an established >development model. We have also given additional reasons in the Rationale >and Alignment sections. > >= Documentation = > >The current documentation for Tephra is at >https://github.com/caskdata/tephra. > >= Initial Source = > >Tephra codebase is currently hosted at https://github.com/caskdata/tephra. > >= Source and Intellectual Property Submission Plan = > >Tephra codebase is currently licensed under Apache 2.0 license. >Cask Data owns the trademark for "Tephra". As part of the incubation >process >Cask Data will transfer the trademark to Apache Foundation. > >= External Dependencies = > >The dependencies all have Apache-compatible licenses: > * dropwizard metrics (Apache 2.0) > * fastutil (Apache 2.0) > * gson (Apache 2.0) > * guava-libraries (Apache 2.0) > * guice (Apache 2.0) > * hadoop (Apache 2.0) > * hbase (Apache 2.0) > * hdfs (Apache 2.0) > * junit (EPL v1.0) > * logback (EPL v1.0 ) > * slf4j (MIT) > * thrift (Apache 2.0) > * twill (Apache 2.0) > * zookeeper (Apache 2.0) > >= Cryptography = > >Tephra does not use cryptography itself, however it can run on secure >Hadoop, >which uses Kerberos. > >= Required Resources = > >== Mailing Lists == > > * tephra-private for private PMC discussions (with moderated >subscriptions) > * tephra-dev for technical discussions among contributors > * tephra-commits for notification about commits > >== Subversion Directory == > >Git is the preferred source control system: git://git.apache.org/tephra > >== Issue Tracking == > >JIRA Tephra (TEPHRA) > >== Other Resources == > >The existing code already has unit tests, so we would like a Hudson >instance to run them whenever a new patch is submitted. This can be added >after project creation. > >= Initial Committers = > > * Andreas Neumann <anew at apache dot org> > * Terence Yim <chtyim at apache dot org> > * Poorna Chandra <poorna at apache dot org> > * Gokul Gunasekaran <gokul at cask dot co> > * James Taylor <jamestaylor at apache dot org> > * Thomas D'Silva <tdsilva at apache dot org> > * Gary Helmling <garyh at apache dot org> > >= Affiliations = > > * Andreas Neumann (Cask Data) > * Terence Yim (Cask Data) > * Poorna Chandra (Cask Data) > * Gokul Gunasekaran (Cask Data) > * James Taylor (Salesforce.com) > * Thomas D'Silva (Salesforce.com) > * Gary Helmling (Facebook) > >= Sponsors = > >== Champion == > >James Taylor <jamestaylor at apache dot org> (V.P., Apache Phoenix) > >== Nominated Mentors == > > * James Taylor <jamestaylor at apache dot org> > * Lars Hofhansl <larsh at apache dot org> > * Andrew Purtell <apurtell at apache dot org> > * Alan Gates <gates at apache dot org> > * Henry Saputra <hsaputra at apache dot org> > >== Sponsoring Entity == > >We are requesting that the Incubator sponsor this project. --------------------------------------------------------------------- To unsubscribe, e-mail: general-unsubscr...@incubator.apache.org For additional commands, e-mail: general-h...@incubator.apache.org
