I would like to call the Incubator PMC to vote to incubate the proposed
Pig project. Discussion on this list evidenced broad interest in this
project, which bodes well for its ability to build a diverse developer
community.
http://wiki.apache.org/incubator/PigProposal
+1
Doug
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= Proposal for Pig Project =
== 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 license
2. javacc: https://javacc.dev.java.net/:BSD license
3. hadoop: http://lucene.apache.org/hadoop/:Apache license
4. log4j: http://logging.apache.org/log4j/: Apache license
5. jsch: http://www.jcraft.com/jsch: BSD style license:
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 ([EMAIL PROTECTED])
2. Alan Gates ([EMAIL PROTECTED])
3. Olga Natkovich ([EMAIL PROTECTED])
4. Chris Olston ([EMAIL PROTECTED])
5. Owen O'Malley ([EMAIL PROTECTED])
6. Ben Reed ([EMAIL PROTECTED])
7. Utkarsh Srivastava ([EMAIL PROTECTED])
== Affiliation ==
All initial committers are affiliated with Yahoo!
== Sponsors ==
=== Champion ===
Doug Cutting
=== Nominated Mentors ===
1. Doug Cutting
2. Torsten Curdt
3. Bertrand Delacretaz
4. Yoav Shapira
5. Sylvain Wallez
=== Sponsoring Entity ===
Incubator
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