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From "Olga Natkovich" <ol...@yahoo-inc.com>
Subject Incubator Proposal: Pig
Date Tue, 18 Sep 2007 19:52:23 GMT
Hi,
 
Yahoo! research and development teams have developed a proposal below. The
proposal is also available on wiki at
<http://wiki.apache.org/incubator/PigProposal>
http://wiki.apache.org/incubator/PigProposal.
We would like to ask that the ASF consider forming a podling according to
the proposal.

Thanks,

Olga Natkovich
 <mailto:olgan@yahoo-inc.com> olgan@yahoo-inc.com

----------------------------------------------------------------------------
---------

= Pig Open Source Proposal =

== Abstract ==

Pig is a platform for analyzing large data sets. 

== Proposal ==

The Pig project consists of high-level languages for expressing data
analysis programs, coupled with infrastructure for evaluating these
programs. The salient property of Pig programs is that their structure is
amenable to substantial parallelization, which in turns enables them to
handle very large data sets.

At the present time, Pig's infrastructure layer consists of a compiler that
produces sequences of Map-Reduce programs, for which large-scale parallel
implementations already exist (e.g., the Hadoop subproject). Pig's language
layer currently consists of a textual language called Pig Latin, which has
the following key properties:

 1. ''Ease of programming''. It is trivial to achieve parallel execution of
simple, "embarrassingly parallel" data analysis tasks. Complex tasks
comprised of multiple interrelated data transformations are explicitly
encoded as data flow sequences, making them easy to write, understand, and
maintain.
 2. ''Optimization opportunities''. The way in which tasks are encoded
permits the system to optimize their execution automatically, allowing the
user to focus on semantics rather than efficiency.
 3. ''Extensibility''. Users can create their own functions to do
special-purpose processing. 

== Background ==

Pig started as a research project at Yahoo! in May of 2006 to combine ideas
in parallel databases and distributed computing. The first internal release
took place in July 2006. The first release was a simple front-end to the
Hadoop Map/Reduce framework. The following releases added new features and
evolved the language based on user feedback. In July 2007, pig was taken
over by a development team and the first production version is due to be
released on 9/28/07.

Since its inception, we had observed a steady growth of the user community
within Yahoo!.  In April 2007, Pig was released under a BSD-type license.
Several external parties are using this version and have expressed interest
in collaborating on its development.

== Rationale ==

In an information-centric world, innovation is driven by ad-hoc analysis of
large data sets. For example, search engine companies routinely deploy and
refine services based on analyzing the recorded behavior of users,
publishers, and advertisers. The rate of innovation depends on the
efficiency with which data can be
analyzed.

To analyze large data sets efficiently, one needs parallelism. The cheapest
and most scalable form of parallelism is cluster computing. Unfortunately,
programming for a cluster computing environment is difficult and
time-consuming. Pig makes it easy to harness the power of cluster computing
for ad-hoc data analysis. 

While other language exist that try to achieve the same goals, we believe
that Pig provides more flexibility and gives more control to the end user. 

SQL typically requires (1) importing data from a user's preferred format
into a database system's internal format (2) well-structured, normalized
data with a declared schema, and (3) programs expressed in declarative
SELECT-FROM-WHERE blocks. In contrast, Pig Latin facilitates (1)
interoperability, i.e. data may be read/written in a format accepted by
other applications such as text editors or graph generators (2) flexibility,
i.e. data may be loosely structured or have structure that is
defined operationally, and (3) adoption by programmers who find procedural
programming more natural than declarative programming.

Sawzall is a scripting language used at Google on top of Map-Reduce. A
sawzall program has a fairly rigid structure consisting of a filtering phase
(the map step) followed by an aggregation phase (the reduce step).
Furthermore, only the filtering phase can be written by the user, and only a
pre-built set of aggregations are available (new ones are non-trivial to
add). While Pig Latin has similar higher level primitives like filtering and
aggregation, an arbitrary number of them can be flexibly chained together in
a Pig Latin program, and all primitives can use user-defined functions with
equal ease. Further, Pig Latin has additional primitives such as cogrouping,
that allow operations such as joins (which require multiple programs in
Sawzall) to be written in a single line in Pig Latin. Further, Pig Latin is
designed
to be embedded into other languages, and can use functions written in other
languages. Thus, in contrast to Sawzall, it directly caters to a large
community of developers without having to make them learn an entirely new
programming language.

== Current Status ==

=== Meritocracy ===

Pig was started as a project that was developed by Yahoo! research team.
Recently we have added a development team that works in harmony with the
research team with both teams actively and successfully contributing to the
project. We are planning to create the environment that encourages
meritocracy and is consistent with the meritocracy principles of Apache.
Within the team we have people actively participating in the Hadoop
subproject.

=== Community ===

Pig has an active user community within Yahoo! that has been steadily
growing. Pig also attracted external users since its release under a
BSD-type license.  Several external parties are using the product and have
expressed interest in collaborating on its development.

Also, since the current version of Pig is built on top of the Hadoop we
believe that we will be able to quickly extend our community by attracting
both the Hadoop users and developers to the project.

=== Core Developers ===

Our contributors come from both research and development world and most have
background in database internals and large scale distributed systems.

=== Alignment ===

Yahoo! seeks to develop Pig collaboratively with others, not to control and
maintain it independently.  Apache offers the best legal and social
framework for such community-based software development.  

Also, the current version of Pig runs on top of the Hadoop's Map-Reduce
infrastructure which is part of Apache. We believe there would be a lot of
synergy between the projects both in terms of users and developers.

== Known Risks ==
=== Orphaned products ===

All current contributors are part of Yahoo which is a major player in the
space and is committed to grid computing. Also we expect high degree of
synergy with Hadoop subproject.

=== Inexperience with Open Source ===

Two of the committers have extensive experience with open source and Apache.
The rest are new to open source and will be guided through the process by
the team members with experience.

=== Homogenous Developers ===

The current list of committers is confined to Yahoo employees. Our plan is
to recruit more committers once the project gets on the way.

=== Reliance on Salaried Developers ===

Currently, all contributors are Yahoo employees. By extending the
development community we are hoping to mitigate this risk.

=== Relationships with Other Apache Products ===

Pig is built on top of Hadoop and we expect deep collaboration with Hadoop
subproject.

=== An Excessive Fascination with the Apache Brand ===

Yahoo already have a strong brand and is not interested in Apache as a way
to gain visibility. Yahoo! seeks to develop Pig collaboratively with others,
not to control and maintain it independently.  Apache offers the best legal
and social framework for such community-based software development.  

== Documentation ==

http://research.yahoo.com/project/pig

== Initial Source ==

The initial source will be donated by Yahoo Inc. The donating company will
contribute the initial code base once the proposal is accepted and necessary
infrastructure has been set up. 

== External Dependencies ==

 1. bzip2:  <http://www.kohsuke.org/bzip2/:Apache>
http://www.kohsuke.org/bzip2/:Apache license
 2. javacc:  <https://javacc.dev.java.net/:BSD>
https://javacc.dev.java.net/:BSD license
 3. hadoop:  <http://lucene.apache.org/hadoop/:Apache>
http://lucene.apache.org/hadoop/:Apache license
 4. log4j:  <http://logging.apache.org/log4j/>
http://logging.apache.org/log4j/: Apache license
 5. jsch:  <http://www.jcraft.com/jsch> http://www.jcraft.com/jsch: BSD
style license:  <http://www.jcraft.com/jsch/LICENSE.txt>
http://www.jcraft.com/jsch/LICENSE.txt 

== Required Resources ==
== Mailing lists ==

We would need the following mailing lists
 1. pig-private (with moderated subscriptions)
 2. pig-dev
 3. pig-commits
 4. pig-user

=== Subversion Directory ===

https://svn.apache.org/repos/asf/incubator/pig

=== Issue Tracking ===

JIRA PIG (PIG)

== Initial Committers ==

 1. Nigel Daley ( <mailto:ndaley@yahoo-inc.com> ndaley@yahoo-inc.com)
 2. Alan Gates ( <mailto:gates@yahoo-inc.com> gates@yahoo-inc.com)
 3. Olga Natkovich ( <mailto:olgan@yahoo-inc.com> olgan@yahoo-inc.com)
 4. Chris Olston ( <mailto:olston@yahoo-inc.com> olston@yahoo-inc.com)
 5. Owen O'Malley ( <mailto:oom@yahoo-inc.com> oom@yahoo-inc.com)
 6. Ben Reed ( <mailto:breed@yahoo-inc.com> breed@yahoo-inc.com)
 7. Utkarsh Srivastava ( <mailto:utkarsh@yahoo-inc.com>
utkarsh@yahoo-inc.com)

== Affiliation ==

All initial committers are affiliated with Yahoo!

== Sponsors ==

=== Champion ===

Doug Cutting 

=== Nominated Mentors ===

Doug Cutting 

=== Sponsoring Entity ===

Incubator



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