I'm late, but let me add my +1 anyways. St.Ack On Thu, Mar 3, 2016 at 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 Don’t 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 HBase’s native data versioning to provide multi-versioned > concurrency control (MVCC) for transactional reads and writes. > With MVCC capability, each transaction sees its own consistent “snapshot” > 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 transaction’s 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 Data’s 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. >
