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Posted to general@incubator.apache.org by qingpeng <qi...@comp.nus.edu.sg> on 2022/04/08 17:54:44 UTC

COOL proposal

Dear Apache Incubator Community,

We propose to contribute COOL as an Apache Incubator project.

COOL is a cohort OLAP system specialized for cohort analysis with 
extremely low latency. The vision of COOL is to address the inefficiency 
of underlying database systems processing cohort analysis (cohort 
queries) which is an emerging and widely-used analysis pattern in 
various areas. By utilizing COOL, we can process complicated cohort 
queries with flexible definitions of cohorts and events in near 
real-time response time.

We need Champions and Mentors, to help guide us on the development of 
this project. Please feel free to contact our team if any of you are 
interested.

Thanks a lot.

Best Regards,
Team of COOL



# COOL proposal

## Abstract
COOL is an online cohort analytical processing system specialized for 
cohort analysis with extremely low latency.


## Proposal
The vision of COOL is to address the inefficiency of underlying database 
systems processing cohort analysis (cohort queries) which is an emerging 
and widely-used analysis pattern in various areas. In COOL, cohort query 
processing is facilitated by specialized operators that involve only two 
fast scans on sophisticated storage to achieve real-time responses.

COOL has been designed to provide user-friendly querying primitives to 
address the pain point of writing complex and lengthy queries for cohort 
analysis using SQL-like languages. Specifically, at least five SQL 
queries are needed for a conventional OLAP database system to perform 
cohort analysis in a non-intrusive manner.

We submit this proposal to donate the COOL system, its related code, and 
artifacts (documentation, website application, wiki, etc) to Apache 
Software Foundation Incubator. We are confident that COOL will further 
promote the diversity of the Apache community and the Apache is able to 
provide COOL with a better environment to build its community, making it 
a useful and efficient tool for large-scale cohort analysis.


##Background
Cohort analysis (https://en.wikipedia.org/wiki/Cohort_analysis for quick 
reference) is a method of analyzing metrics across different groups 
(i.e., cohorts), which share common characteristics in the accumulated 
data. These characteristics play a critical role in user profiling and 
the decision-making process in data-driven organizations.

For example, cohort analysis is useful in customer retention analysis 
and the effectiveness of a promotional event. Observing the growth of 
users alongside running the user acquisition, or observing player 
progression in online gaming, we can evaluate how different groups of 
players evolve as time progresses. The efficiency of cohort query 
processing is vital in such a scenario as analysts may have to work out 
strategies promptly for the online service.

Another example of cohort analysis could be a side-effect evaluation of 
a clinical trial, in which the clinicians want to monitor and determine 
the effectiveness of new medicines among different patient groups.  
Unlike the analysts for online services, the clinicians can wait for a 
much longer duration (over months or even years) to study the 
effectiveness of treatments, etc. However, it is difficult for any 
clinician to construct complex cohort queries (using SQL) to conduct 
cohort analysis.

With the target of providing near real-time cohort analysis responses, 
COOL was initiated as a research project around 2016. It has been used 
for various real-world applications, such as sales of online game 
gadgets/equipment, and sales of virtual assets and gears in online 
games. The COOL system has been designed as a very efficient cohort 
analytical processing system with a fast response time and flexible 
definition of cohorts and events. It is at least one order of magnitude 
faster than cohort processing using a conventional database engine.

For ease of use, COOL accepts a single self-defined query in JSON 
format, rather than multiple complex SQL statements.


##Rationale
There is a strong need to support cohort analysis efficiently and 
effectively with the society evolving and COOL meets such need greatly. 
The querying response of cohort analysis in COOL is real-time, which is 
at least one order of magnitude compared to traditional OLAP systems. 
Meanwhile, COOL accepts a single self-defined query in JSON format, 
rather than multiple complex SQL statements. Besides, COOL can also 
integrate data from different data sources.


##Initial Goals
The initial goal is to move the existing codebase to Apache Software 
Foundation and improve it with the standard Apache development process.
We plan for incremental development in the following directions: more 
storage connectors, more file format parsers, a feasible caching 
mechanism, and utilizing COOL's cohort results to facilitate building 
machine learning models.  All these will be released in stages with the 
community following the Apache process.


##Current Status
COOL was started as a research project in the database system lab of NUS 
around 2016. All the codes are made available under Apache License V2, 
and the related artifacts can be found on Github.
The introduction website of the COOL system: http://13.212.103.48:3001/
The GitHub for the source code of the COOL system: 
https://github.com/COOL-cohort/COOL
The GitHub for the source code of the COOL website: 
https://github.com/COOL-cohort/COOL-site
The GitHub for the source code of the COOL webapp: 
https://github.com/COOL-cohort/COOL-webapp

###Meritocracy
The project was originally created by David Jiang,  Qingchao Cai, and 
Zhongle Xie. And the project now has committers and users from both 
different organizations in Singapore and China.
The committers of the project are all joined by submitting codes fixing 
bugs and providing new features. If the proposal were accepted, we would 
work to select PPMC members for the project and continuously operate in 
the Apache way.

###Community
Although we are in the early stage of building a well-organized 
community, the need for cohort analysis is growing, especially as part 
of deep customer relationship management (CRM) and medical cohort 
analysis.  Therefore, COOL should be able to attract more contributors 
to join our community to improve its codebase. Besides, we also have 
many experienced developers who have participated in building the Apache 
SINGA and other open sources, and we are capable of organizing a 
well-developed community for COOL.

###Core Developers
Thus far, the core developers of COOL are experienced researchers and 
engineers primarily from the National Unversity of Singapore and 
Zhejiang University. Some of them had participated in Apache Singa and 
have adequate open-source experience.

###Alignment
Apache Incubator would be a perfect fit for the project for the 
following reasons:
1. COOL enriches the ecosystem of OLAP systems for underlying Apache 
Projects since there is no specialized cohort analytical system in the 
current project list.
2. The developer team of COOL is familiar with the Apache process and 
way. The lab has already contributed Apache SINGA, a Top-Level Project, 
to the foundation and a few members from Apache SINGA have joined the 
COOL team.
3. Joining Apache can help attract and coordinate development efforts 
from companies.
4. COOL can naturally connect with Apache projects like HDFS and 
ZooKeeper.



##Known Risks
Currently, the development team members are mostly from universities and 
research institutions. The team fully becomes an "Apache-style" project, 
the project needs to embrace more developers from the industry or the 
community.

###Project Name
The name (i.e., COOL) is short and easy to be remembered, and we do not 
find any similar names or projects which may cause conflict to the best 
of our knowledge. Hence, we believe the name COOL should be suitable for 
this project.

###Orphaned products
We believe that the COOL system will draw more attention from users in 
the industry and attract more developers to contribute to both the 
codebase and community because COOL can not only conduct cohort analysis 
with extremely low latency but also simplify the cohort queries without 
defining complex joint expressions.
We have already developed a website application to facilitate possible 
users to use our COOL system to conduct cohort analysis.
In practice, we also have deployed the COOL system in National 
University Health System to assist clinicians in analyzing insightful 
patterns among COVID19 patients from cohort results. Meanwhile, the team 
has cooperated with a few companies in building their user cohort 
analysis applications.
We plan to improve the COOL system from different aspects, such as more 
storage connectors, more file format parsers, a feasible caching 
mechanism, and utilizing COOL's cohort results to facilitate building 
machine learning models.

###Inexperience with Open Source
Our initial committers include several experienced developers who had 
participated in the Apache SINGA project. In fact, some of them are the 
core contributors and from the PPMC of the project. Hence, we have the 
experience to grow the community and maintain participation.

###Length of Incubation
We have made preliminary plans on improving the COOL from different 
aspects and are devoted to realizing them. Besides, our committers are 
experienced in developing open-source projects and have participated in 
growing a well-organized community. Hence, we believe all these steps 
are realizable.

###Homogenous Developers
The current core developers mainly are researchers from the National 
University of Singapore and Zhejiang University. We also have a small 
number of developers from ByteDance and other enterprises. We do want to 
build a well-organized community and encourage developers to join and 
promote the development of our COOL system.

###Reliance on Salaried Developers
Most of the developers are working for research labs, and universities 
or are studying for their doctorate. They build the COOL system while 
conducting their research on cohort analysis and cohort-based neural 
network models. The COOL system will be a powerful tool to facilitate 
advanced cohort analytics in the commercial world and scientific 
research that exploit the use of cohort of analysis (eg. Reaction to 
drugs and treatments.)

###Relationships with Other Apache Products
COOL has naturally connected with Apache projects like HDFS and 
ZooKeeper. Besides, COOL is supporting Parquet files as a method to load 
data from other systems into COOL and export data for other downstream 
analysis tasks. Supports for Apache Avro and Apache Arrow are also on 
our schedule.

###A Excessive Fascination with the Apache Brand
Without a doubt, we appreciate the reputation of the Apache brand, which 
will help to attract contributors and users. We also appreciate the 
Apache development process. We believe that COOL, as a specialized OLAP 
system for cohort analysis, can promote the diversification of the 
Apache community.



##Documentation
The introduction of the COOL system can be found in: 
http://13.212.103.48:3001/


##Initial Source
The codebase of the COOL system is based on Java and relies on Maven to 
compile and build the COOL engine. Besides, we also prepare website 
applications and interesting use cases to demonstrate how to leverage 
COOL. More details can be found on the Introduction webpage or the Git 
repositories.

###Source and Intellectual Property Submission Plan
Once COOL is accepted and sponsored by Apache, we can transfer all 
source codes and copyrights to the Apache Software Foundation.

###External Dependencies
All dependencies of the COOL system comply with the Apache License V2.

###Cryptography
Not applicable to COOL.


##Required Resources
###Mailing lists
We plan to use the following mailing lists:
• users@cool.incubator.apache.org
• dev@cool.incubator.apache.org
• private@cool.incubator.apache.org
• commits@cool.incubator.apache.org

###Subversion Directory
We prefer to continue using Git to control our COOL system development.

###Git Repositories
• COOL system: https://github.com/COOL-cohort/COOL
• COOL website: https://github.com/COOL-cohort/COOL-site
• COOL webapp: https://github.com/COOL-cohort/COOL-webapp

###Issue Tracking
We would like to use JIRA to track issues.


##Initial Committers
• Beng Chin Ooi (ooibc@comp.nus.edu.sg)
• Zhongle Xie (xiezl@zju.edu.cn)
• Meihui Zhang (meihui_zhang@bit.edu.cn)
• Qingpeng Cai (qingpeng@comp.nus.edu.sg)
• Naili Xing (dcsxing@nus.edu.sg)
• Guoyu Hu (guoyu.hu@u.nus.edu)
• Hongbin Ying (yinghongbin@mzhtechnologies.com)
• Changshuo Liu (changshuo@u.nus.edu)
• Fei Xiao (fxiao004@comp.nus.edu.sg)
• Yuncheng Wu (dcswuyu@nus.edu.sg)
• Gang Chen (cg@zju.edu.cn)
• Pengyuan Shen (shenpy@mzhtechnologies.com)
• Chenghao Cai (chenghao.cai@nusri.cn)
• Ishant virendra Wankhede (ishant.virendra.wankhede@walmart.com)


##Affiliations
• Beng Chin Ooi, National University of Singapore
• Zhongle Xie, Zhejiang University
• Meihui Zhang, Beijing Institute of Technology
• Qingpeng Cai, National University of Singapore
• Naili Xing, National University of Singapore
• Hongbin Ying, MZH Technologies
• Guoyu Hu, National University of Singapore
• Changshuo Liu, National University of Singapore
• Fei Xiao, National University of Singapore
• Yuncheng Wu, National University of Singapore
• Gang Chen, Zhejiang University
• Pengyuan Shen, MZH Technologies
• Chenghao Cai, NUS AI Innovation and Commercialisation Centre
• Ishant virendra Wankhede, Walmart


##Sponsors
###Champion
TODO
###Nominated Mentors
TODO
###Sponsoring Entity
The Apache Incubator

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Proposal: to incubate a 100% java based Cohort OLAP system

Posted by Beng Chin OOI <oo...@comp.nus.edu.sg>.

Dear Apache Incubator Community,

This was earlier sent by QingPeng.

I am Beng Chin --  the initiator and a PMC of Apache SINGA 
(https://singa.apache.org/) -- an Apache top level project.

We would like to contribute COOL as an Apache Incubator project.

COOL is a cohort OLAP system specialized for cohort analysis with 
extremely low latency. The vision of COOL is to address the inefficiency 
of underlying database systems for cohort analysis (cohort queries) 
which is increasingly used in areas such as customer acquisition and 
CRM, medical cohort analysis (response of patients with respect to 
treatment/medicine etc) and fraud detection.

COOL is very fast -- one to two order magnitude faster than 
implementation on known database systems using SQL.

It is flexible and powerful  -- it can process complicated cohort 
queries with flexible definitions of cohorts
and events in near real-time response time.

COOL works with a few open source storage engines/backends, namely, 
Apache Avro, Apache Arrow, Apache Parquet, etc.

We need Champions and Mentors, to help guide us on further development 
of this open source project.

Thanks.


Regards,
Beng Chin Ooi
www.comp.nus.edu.sg/~ooibc

on behalf of COOL team


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



# COOL proposal

## Abstract
COOL is an online cohort analytical processing system specialized for 
cohort analysis with extremely low latency.


## Proposal
The vision of COOL is to address the inefficiency of underlying database 
systems processing cohort analysis (cohort queries) which is an emerging 
and widely-used analysis pattern in various areas. In COOL, cohort query 
processing is facilitated by specialized operators that involve only two 
fast scans on sophisticated storage to achieve real-time responses.

COOL has been designed to provide user-friendly querying primitives to 
address the pain point of writing complex and lengthy queries for cohort 
analysis using SQL-like languages. Specifically, at least five SQL 
queries are needed for a conventional OLAP database system to perform 
cohort analysis in a non-intrusive manner.

We submit this proposal to donate the COOL system, its related code, and 
artifacts (documentation, website application, wiki, etc) to Apache 
Software Foundation Incubator. We are confident that COOL will further 
promote the diversity of the Apache community and the Apache is able to 
provide COOL with a better environment to build its community, making it 
a useful and efficient tool for large-scale cohort analysis.


##Background
Cohort analysis (https://en.wikipedia.org/wiki/Cohort_analysis for quick 
reference) is a method of analyzing metrics across different groups 
(i.e., cohorts), which share common characteristics in the accumulated 
data. These characteristics play a critical role in user profiling and 
the decision-making process in data-driven organizations.

For example, cohort analysis is useful in customer retention analysis 
and the effectiveness of a promotional event. Observing the growth of 
users alongside running the user acquisition, or observing player 
progression in online gaming, we can evaluate how different groups of 
players evolve as time progresses. The efficiency of cohort query 
processing is vital in such a scenario as analysts may have to work out 
strategies promptly for the online service.

Another example of cohort analysis could be a side-effect evaluation of 
a clinical trial, in which the clinicians want to monitor and determine 
the effectiveness of new medicines among different patient groups.  
Unlike the analysts for online services, the clinicians can wait for a 
much longer duration (over months or even years) to study the 
effectiveness of treatments, etc. However, it is difficult for any 
clinician to construct complex cohort queries (using SQL) to conduct 
cohort analysis.

With the target of providing near real-time cohort analysis responses, 
COOL was initiated as a research project around 2016. It has been used 
for various real-world applications, such as sales of online game 
gadgets/equipment, and sales of virtual assets and gears in online 
games. The COOL system has been designed as a very efficient cohort 
analytical processing system with a fast response time and flexible 
definition of cohorts and events. It is at least one order of magnitude 
faster than cohort processing using a conventional database engine.

For ease of use, COOL accepts a single self-defined query in JSON 
format, rather than multiple complex SQL statements.


##Rationale
There is a strong need to support cohort analysis efficiently and 
effectively with the society evolving and COOL meets such need greatly. 
The querying response of cohort analysis in COOL is real-time, which is 
at least one order of magnitude compared to traditional OLAP systems. 
Meanwhile, COOL accepts a single self-defined query in JSON format, 
rather than multiple complex SQL statements. Besides, COOL can also 
integrate data from different data sources.


##Initial Goals
The initial goal is to move the existing codebase to Apache Software 
Foundation and improve it with the standard Apache development process.
We plan for incremental development in the following directions: more 
storage connectors, more file format parsers, a feasible caching 
mechanism, and utilizing COOL's cohort results to facilitate building 
machine learning models.  All these will be released in stages with the 
community following the Apache process.


##Current Status
COOL was started as a research project in the database system lab of NUS 
around 2016. All the codes are made available under Apache License V2, 
and the related artifacts can be found on Github.
The introduction website of the COOL system: http://13.212.103.48:3001/
The GitHub for the source code of the COOL system: 
https://github.com/COOL-cohort/COOL
The GitHub for the source code of the COOL website: 
https://github.com/COOL-cohort/COOL-site
The GitHub for the source code of the COOL webapp: 
https://github.com/COOL-cohort/COOL-webapp

###Meritocracy
The project was originally created by David Jiang,  Qingchao Cai, and 
Zhongle Xie. And the project now has committers and users from both 
different organizations in Singapore and China.
The committers of the project are all joined by submitting codes fixing 
bugs and providing new features. If the proposal were accepted, we would 
work to select PPMC members for the project and continuously operate in 
the Apache way.

###Community
Although we are in the early stage of building a well-organized 
community, the need for cohort analysis is growing, especially as part 
of deep customer relationship management (CRM) and medical cohort 
analysis.  Therefore, COOL should be able to attract more contributors 
to join our community to improve its codebase. Besides, we also have 
many experienced developers who have participated in building the Apache 
SINGA and other open sources, and we are capable of organizing a 
well-developed community for COOL.

###Core Developers
Thus far, the initial core developers of COOL are experienced 
researchers and engineers primarily from the National Unversity of 
Singapore and Zhejiang University. We have new developers from US 
industry.
A few early core developers have been involved in Apache SINGA and hence 
are familiar with Apache process.

###Alignment
Apache Incubator would be a perfect fit for the project for the 
following reasons:
1. COOL enriches the ecosystem of OLAP systems for underlying Apache 
Projects since there is no specialized cohort analytical system in the 
current project list.
2. The developer team of COOL is familiar with the Apache process and 
way. The lab has already contributed Apache SINGA, a Top-Level Project, 
to the foundation and a few members from Apache SINGA have joined the 
COOL team.
3. Joining Apache can help attract and coordinate development efforts 
from companies.
4. COOL can naturally connect with Apache projects like HDFS and 
ZooKeeper.



##Known Risks
Currently, the development team members are mostly from universities and 
research institutions. The team fully becomes an "Apache-style" project, 
the project needs to embrace more developers from the industry or the 
community.

###Project Name
The name (i.e., COOL) is short and easy to be remembered, and we do not 
find any similar names or projects which may cause conflict to the best 
of our knowledge. Hence, we believe the name COOL should be suitable for 
this project.

###Orphaned products
We believe that the COOL system will draw more attention from users in 
the industry and attract more developers to contribute to both the 
codebase and community because COOL can not only conduct cohort analysis 
with extremely low latency but also simplify the cohort queries without 
defining complex joint expressions.
We have already developed a website application to facilitate possible 
users to use our COOL system to conduct cohort analysis.
In practice, we also have deployed the COOL system in National 
University Health System to assist clinicians in analyzing insightful 
patterns among COVID19 patients from cohort results. Meanwhile, the team 
has cooperated with a few companies in building their user cohort 
analysis applications.
We plan to improve the COOL system from different aspects, such as more 
storage connectors, more file format parsers, a feasible caching 
mechanism, and utilizing COOL's cohort results to facilitate building 
machine learning models.

###Inexperience with Open Source
Our initial committers include several experienced developers who had 
participated in the Apache SINGA project. In fact, some of them are the 
core contributors and from the PPMC of the project. Hence, we have the 
experience to grow the community and maintain participation.

###Length of Incubation
We have made preliminary plans on improving the COOL from different 
aspects and are devoted to realizing them. Besides, our committers are 
experienced in developing open-source projects and have participated in 
growing a well-organized community. Hence, we believe all these steps 
are realizable.

###Homogenous Developers
The current core developers mainly are researchers from the National 
University of Singapore and Zhejiang University. We also have a small 
number of developers from ByteDance and other enterprises. We do want to 
build a well-organized community and encourage developers to join and 
promote the development of our COOL system.

###Reliance on Salaried Developers
Most of the developers are working for research labs, and universities 
or are studying for their doctorate. They build the COOL system while 
conducting their research on cohort analysis and cohort-based neural 
network models. The COOL system will be a powerful tool to facilitate 
advanced cohort analytics in the commercial world and scientific 
research that exploit the use of cohort of analysis (eg. Reaction to 
drugs and treatments.)

###Relationships with Other Apache Products
COOL has naturally connected with Apache projects like HDFS and 
ZooKeeper. Besides, COOL is supporting Parquet files as a method to load 
data from other systems into COOL and export data for other downstream 
analysis tasks. Supports for Apache Avro and Apache Arrow are also on 
our schedule.

###A Excessive Fascination with the Apache Brand
Without a doubt, we appreciate the reputation of the Apache brand, which 
will help to attract contributors and users. We also appreciate the 
Apache development process. We believe that COOL, as a specialized OLAP 
system for cohort analysis, can promote the diversification of the 
Apache community.



##Documentation
The introduction of the COOL system can be found in: 
http://13.212.103.48:3001/


##Initial Source
The codebase of the COOL system is based on Java and relies on Maven to 
compile and build the COOL engine. Besides, we also prepare website 
applications and interesting use cases to demonstrate how to leverage 
COOL. More details can be found on the Introduction webpage or the Git 
repositories.

###Source and Intellectual Property Submission Plan
Once COOL is accepted and sponsored by Apache, we can transfer all 
source codes and copyrights to the Apache Software Foundation.

###External Dependencies
All dependencies of the COOL system comply with the Apache License V2.

###Cryptography
Not applicable to COOL.


##Required Resources
###Mailing lists
We plan to use the following mailing lists:
• users@cool.incubator.apache.org
• dev@cool.incubator.apache.org
• private@cool.incubator.apache.org
• commits@cool.incubator.apache.org

###Subversion Directory
We prefer to continue using Git to control our COOL system development.

###Git Repositories
• COOL system: https://github.com/COOL-cohort/COOL
• COOL website: https://github.com/COOL-cohort/COOL-site
• COOL webapp: https://github.com/COOL-cohort/COOL-webapp

###Issue Tracking
We would like to use JIRA to track issues.


##Initial Committers
• Beng Chin Ooi (ooibc@comp.nus.edu.sg)
• Zhongle Xie (xiezl@zju.edu.cn)
• Meihui Zhang (meihui_zhang@bit.edu.cn)
• Qingpeng Cai (qingpeng@comp.nus.edu.sg)
• Naili Xing (dcsxing@nus.edu.sg)
• Guoyu Hu (guoyu.hu@u.nus.edu)
• Hongbin Ying (yinghongbin@mzhtechnologies.com)
• Changshuo Liu (changshuo@u.nus.edu)
• Fei Xiao (fxiao004@comp.nus.edu.sg)
• Yuncheng Wu (dcswuyu@nus.edu.sg)
• Gang Chen (cg@zju.edu.cn)
• Pengyuan Shen (shenpy@mzhtechnologies.com)
• Chenghao Cai (chenghao.cai@nusri.cn)
• Ishant virendra Wankhede (ishant.virendra.wankhede@walmart.com)
* Linsey Pang (xpang@salesforce.com; panglinsey@gmail.com)
* Raghav Chalapathy (raghav.chalapathy@gmail.com; 
raghav.chalapathy@walmart.com)

##Affiliations
• Beng Chin Ooi, National University of Singapore
• Zhongle Xie, Zhejiang University
• Meihui Zhang, Beijing Institute of Technology
• Qingpeng Cai, National University of Singapore
• Naili Xing, National University of Singapore
• Hongbin Ying, MZH Technologies
• Guoyu Hu, National University of Singapore
• Changshuo Liu, National University of Singapore
• Fei Xiao, National University of Singapore
• Yuncheng Wu, National University of Singapore
• Gang Chen, Zhejiang University
• Pengyuan Shen, MZH Technologies
• Chenghao Cai, NUS AI Innovation and Commercialisation Centre
• Ishant virendra Wankhede, Walmart
* Linsey Pang, Salesforce
* Raghav Chalapathy, Walmart


##Sponsors
###Champion
TODO
###Nominated Mentors
TODO
###Sponsoring Entity
The Apache Incubator

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