Nice! Is this related to HBase? Or similar to it? mahadev
On Fri, Sep 2, 2011 at 9:27 AM, Patrick Hunt <ph...@apache.org> wrote: > FYI, another project using ZK -- woot!!! (note that they have their > own WAL - perhaps a good application for BookKeeper?) > > ---------- Forwarded message ---------- > From: Billie J Rinaldi <billie.j.rina...@ugov.gov> > Date: Fri, Sep 2, 2011 at 8:45 AM > Subject: [PROPOSAL] Accumulo for the Apache Incubator > To: gene...@incubator.apache.org > > > Greetings, > > I would like to propose Accumulo to be an Apache Incubator project. > Accumulo is a distributed key/value store that provides expressive > cell-level access labels and a server-side programming mechanism that > can modify key/value pairs at various points in the data management > process. It is based on Google's BigTable design and runs over Apache > Hadoop and Zookeeper. > > Here is a link to the proposal in the Incubator wiki: > http://wiki.apache.org/incubator/AccumuloProposal > > I've also pasted the initial contents below. > > Thanks, > Billie Rinaldi > > > = Accumulo Proposal = > > == Abstract == > Accumulo is a distributed key/value store that provides expressive, > cell-level access labels. > > == Proposal == > Accumulo is a sorted, distributed key/value store based on Google's > BigTable design. It is built on top of Apache Hadoop, Zookeeper, and > Thrift. It features a few novel improvements on the BigTable design > in the form of cell-level access labels and a server-side programming > mechanism that can modify key/value pairs at various points in the > data management process. > > == Background == > Google published the design of BigTable in 2006. Several other open > source projects have implemented aspects of this design including > HBase, CloudStore, and Cassandra. Accumulo began its development in > 2008. > > == Rationale == > There is a need for a flexible, high performance distributed key/value > store that provides expressive, fine-grained access labels. The > communities we expect to be most interested in such a project are > government, health care, and other industries where privacy is a > concern. We have made much progress in developing this project over > the past 3 years and believe both the project and the interested > communities would benefit from this work being openly available and > having open development. > > == Current Status == > > === Meritocracy === > We intend to strongly encourage the community to help with and > contribute to the code. We will actively seek potential committers > and help them become familiar with the codebase. > > === Community === > A strong government community has developed around Accumulo and > training classes have been ongoing for about a year. Hundreds of > developers use Accumulo. > > === Core Developers === > The developers are mainly employed by the National Security Agency, > but we anticipate interest developing among other companies. > > === Alignment === > Accumulo is built on top of Hadoop, Zookeeper, and Thrift. It builds > with Maven. Due to the strong relationship with these Apache > projects, the incubator is a good match for Accumulo. > > == Known Risks == > === Orphaned Products === > There is only a small risk of being orphaned. The community is > committed to improving the codebase of the project due to its > fulfilling needs not addressed by any other software. > > === Inexperience with Open Source === > The codebase has been treated internally as an open source project > since its beginning, and the initial Apache committers have been > involved with the code for multiple years. While our experience with > public open source is limited, we do not anticipate difficulty in > operating under Apache's development process. > > === Homogeneous Developers === > The committers have multiple employers and it is expected that > committers from different companies will be recruited. > > === Reliance on Salaried Developers === > The initial committers are all paid by their employers to work on > Accumulo and we expect such employment to continue. Some of the > initial committers would continue as volunteers even if no longer > employed to do so. > > === Relationships with Other Apache Products === > Accumulo uses Hadoop, Zookeeper, Thrift, Maven, log4j, commons-lang, > -net, -io, -jci, -collections, -configuration, -logging, and -codec. > > === Relationship to HBase === > Accumulo and HBase are both based on the design of Google's BigTable, > so there is a danger that potential users will have difficulty > distinguishing the two or that they will not see an incentive in > adopting Accumulo. There are a few key areas in which Accumulo > differs from HBase. Some of the desired features of Accumulo could be > incorporated into HBase, however the most important of these may be > unlikely to be adopted (see cell-level access labels and iterators > below). It is a possibility that the codebases will ultimately > converge, but the number of differences at the current time warrants a > separate project for Accumulo. > > ==== Access Labels ==== > Accumulo has an additional portion of its key that sorts after the > column qualifier and before the timestamp. It is called column > visibility and enables expressive cell-level access control. > Authorizations are passed with each query to control what data is > returned to the user. The column visibilities are boolean AND and OR > combinations of arbitrary strings (such as "(A&B)|C") and > authorizations are sets of strings (such as {C,D}). > > ==== Iterators ==== > Accumulo has a novel server-side programming mechanism that can modify > the data written to disk or returned to the user. This mechanism can > be configured for any of the scopes where data is read from or written > to disk. It can be used to perform joins on data within a single > tablet. > > ==== Flexibility ==== > HBase requires the user to specify the set of column families to be > used up front. Accumulo places no restrictions on the column > families. Also, each column family in HBase is stored separately on > disk. Accumulo allows column families to be grouped together on disk, > as does BigTable. This enables users to configure how their data is > stored, potentially providing improvements in compression and lookup > speeds. It gives Accumulo a row/column hybrid nature, while HBase is > currently column-oriented. > > ==== Testing ==== > Accumulo has testing frameworks that have resulted in its achieving a > high level of correctness and performance. We have observed that > under some configurations and conditions Accumulo will outperform > HBase and provide greater data integrity. > > ==== Logging ==== > HBase uses a write-ahead log on the Hadoop Distributed File System. > Accumulo has its own logging service that does not depend on > communication with the HDFS NameNode. > > ==== Storage ==== > Accumulo has a relative key file format that improves compression. > > ==== Areas in which HBase features improvements over Accumulo ==== > in memory tables, upserts, coprocessors, connections to other projects > such as Cascading and Pig > > === Expectations === > There is a risk that Accumulo will be criticized for not providing > adequate security. The access labels in Accumulo do not in themselves > provide a complete security solution, but are a mechanism for labeling > each piece of data with the authorizations that are necessary to see > it. > > === Apache Brand === > Our interest in releasing this code as an Apache incubator project is > due to its strong relationship with other Apache projects, i.e. > Hadoop, Zookeeper, and HBase. > > == Documentation == > There is not currently documentation about Accumulo on the web, but a > fair amount of documentation and training materials exists and will be > provided on the Accumulo wiki at apache.org. Also, a paper discussing > YCSB results for Accumulo will be presented at the 2011 Symposium on > Cloud Computing. > > == Initial Source == > Accumulo has been in development since spring 2008. There are > hundreds of developers using it and tens of developers have > contributed to it. The core codebase consists of 200,000 lines of > code (mainly Java) and 100s of pages of documentation. There are also > a few projects built on top of Accumulo that may be added to its > contrib in the future. These include support for Hive, Matlab, YCSB, > and graph processing. > > == Source and Intellectual Property Submission Plan == > Accumulo core code, examples, documention, and training materials will > be submitted by the National Security Agency. > > We will also be soliciting contributions of further plugins from MIT > Lincoln Labs, Carnegie Mellon University, and others. > > Accumulo has been developed by a mix of government employees and > private companies under government contract. Material developed by > government employees is in the public domain and no U.S. copyright > exists in works of the federal government. For the contractor > developed material in the initial submission, the U.S. Government has > sufficient authority per the ICLA from the copyright owner to > contribute the Accumulo code to the incubator. > > There has been some discussion regarding accepting contributions from > US Government sources on > [https://issues.apache.org/jira/browse/LEGAL-93 LEGAL-93]. We propose > that the NSA will sign an ICLA/CCLA if that document could be slightly > modified to explicitly address copyright in works of government > employees. Specifically, we propose that the definition of “You” be > modified to include “the copyright owner, the owner of a Contribution > not subject to copyright, or legal entity authorized by the copyright > owner that is making this Agreement.” In addition, section 2, the > copyright license grant be modified after “You hereby grant” that > either states “to the extent authorized by law” or “to the extent > copyright exists in the Contribution.” These changes will permit US > Government employee developed work to be included. > > One proposed solution is to form a Collaborative Research and > Development Agreement (CRADA) between the Apache Software Foundation > and the US Government, but this will not solve the underlying problem > that U.S. law does not grant copyright to works of government > employees. At this time a CRADA is not necessary but should it be > determined that a CRADA is necessary, we would like to work through > that process during the incubation phase of Accumulo rather than > before acceptance as this may take time to enter into an agreement. > > == External Dependencies == > jetty (Apache and EPL), jline (BSD), jfreechart (LGPL), jcommon > (LGPL), slf4j (MIT), junit (CPL) > > == Cryptography == > none > > == Required Resources == > * Mailing Lists > * accumulo-private > * accumulo-dev > * accumulo-commits > * accumulo-user > > * Subversion Directory > * https://svn.apache.org/repos/asf/incubator/accumulo > > * Issue Tracking > * JIRA Accumulo (ACCUMULO) > > * Continuous Integration > * Jenkins builds on https://builds.apache.org/ > > * Web > * http://incubator.apache.org/accumulo/ > * wiki at http://wiki.apache.org or http://cwiki.apache.org > > == Initial Committers == > * Aaron Cordova (aaron at cordovas dot org) > * Adam Fuchs (adam.p.fuchs at ugov dot gov) > * Eric Newton (ecn at swcomplete dot com) > * Billie Rinaldi (billie.j.rinaldi at ugov dot gov) > * Keith Turner (keith.turner at ptech-llc dot com) > * John Vines (john.w.vines at ugov dot gov) > * Chris Waring (christopher.a.waring at ugov dot gov) > > == Affiliations == > * Aaron Cordova, The Interllective > * Adam Fuchs, National Security Agency > * Eric Newton, SW Complete Incorporated > * Billie Rinaldi, National Security Agency > * Keith Turner, Peterson Technology LLC > * John Vines, National Security Agency > * Chris Waring, National Security Agency > > == Sponsors == > * Champion: Doug Cutting > * Nominated Mentors: Benson Margulies, ?, ? > * Sponsoring Entity: Apache Incubator > > --------------------------------------------------------------------- > To unsubscribe, e-mail: general-unsubscr...@incubator.apache.org > For additional commands, e-mail: general-h...@incubator.apache.org >
