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Posted to dev@zookeeper.apache.org by Patrick Hunt <ph...@apache.org> on 2011/09/02 18:27:54 UTC
Fwd: [PROPOSAL] Accumulo for the Apache Incubator
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 <bi...@ugov.gov>
Date: Fri, Sep 2, 2011 at 8:45 AM
Subject: [PROPOSAL] Accumulo for the Apache Incubator
To: general@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
---------------------------------------------------------------------
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Re: [PROPOSAL] Accumulo for the Apache Incubator
Posted by Patrick Hunt <ph...@apache.org>.
Seems similar, see the proposal, there are a few sections that call
out the differences. (search for "hbase")
On Fri, Sep 2, 2011 at 9:45 AM, Mahadev Konar <ma...@hortonworks.com> wrote:
> 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 <bi...@ugov.gov>
>> Date: Fri, Sep 2, 2011 at 8:45 AM
>> Subject: [PROPOSAL] Accumulo for the Apache Incubator
>> To: general@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-unsubscribe@incubator.apache.org
>> For additional commands, e-mail: general-help@incubator.apache.org
>>
>
Re: [PROPOSAL] Accumulo for the Apache Incubator
Posted by Mahadev Konar <ma...@hortonworks.com>.
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 <bi...@ugov.gov>
> Date: Fri, Sep 2, 2011 at 8:45 AM
> Subject: [PROPOSAL] Accumulo for the Apache Incubator
> To: general@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
>
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