I would like to propose Weave, an abstraction over Apache Hadoop® YARN to reduce the complexity of developing distributed applications, as an Apache Incubator podling.
The proposal is included in plain text. I would also like to put this on the wiki, but I appear to lack privileges to create pages. What do I need to do to get permission? -Andreas. Abstract ======== Weave is an abstraction over Apache Hadoop® YARN that reduces the complexity of developing distributed applications, allowing developers to focus more on their business logic. Proposal ======== Weave is a set of libraries that reduces the complexity of developing distributed applications. It exposes the distributed capabilities of Apache Hadoop® YARN via a simple and intuitive programming model similar to Java threads. Weave also has built-in capabilities required by many distributed applications, such as real-time application logs and metrics collection, application lifecycle management, and network service discovery. Background ========== Hadoop YARN is a generic cluster resource manager that supports any type of distributed application. However, YARN’s interfaces are too low level for rapid application development. It requires a great deal of boilerplate code even for a simple application, creating a high ramp up cost that can turn developers away. Weave is designed to improve this situation with a programming model that makes running distributed applications as easy as running Java threads. With the abstraction provided by Weave, applications can be executed in process threads during development and unit testing and then be deployed to a YARN cluster without any modifications. Weave also has built-in support for real-time application logs and metrics collection, delegation token renewal, application lifecycle management, and network service discovery. This greatly reduces the pain that developers face when developing, debugging, deploying and monitoring distributed applications. Weave is not a replacement for YARN, it’s a framework that operates on top of YARN. Rationale ========= Developers who write YARN applications typically find themselves implementing the same (or similar) boilerplate code over and over again for every application. It makes sense to distill this common code into a reusable set of libraries that is perpetually maintained and improved by a diverse community of developers. Weave’s simple thread-like programming model will enable many Java programmers to develop distributed applications. We believe that this simplicity will attract developers who would otherwise be discouraged by complexity, and many new use cases will emerge for the usage of YARN. Incubating Weave as an Apache project makes sense because Weave is a framework built on top of YARN, and Weave uses Apache Zookeeper, HDFS, Kafka, and other Apache software (see the External Dependencies section). Current Status ============== Weave was initially developed at Continuuity. The Weave codebase is currently hosted in a public repository at github.com, which will seed the Apache git repository. Meritocracy ----------- Our intent with this incubator proposal is to start building a diverse developer community around Weave following the Apache meritocracy model. Since Weave was initially developed in early 2013, we have had fast adoption and contributions within Continuuity. We are looking forward to new contributors. We wish to build a community based on Apache's meritocracy principles, working with those who contribute significantly to the project and welcoming them to be committers both during the incubation process and beyond. Community --------- Weave is currently being used internally at Continuuity and is at the core of our products. We hope to extend our contributor base significantly and we will invite all who are interested in simplifying the development of distributed applications to participate. Core Developers --------------- Weave is currently being developed by five engineers at Continuuity: Terence Yim, Andreas Neumann, Gary Helmling, Poorna Chandra and Albert Shau. Terence Yim is an Apache committer for Helix, Andreas is an Apache committer and PMC member for Oozie, and Gary Helmling is an Apache committer and PMC member for HBase. Poorna Chandra and Albert Shau have made many contributions to Weave. Alignment --------- The ASF is the natural choice to host the Weave project as its goal of encouraging community-driven open source projects fits with our vision for Weave. Additionally, many other projects with which we are familiar and expect Weave to integrate with, such as ZooKeeper, YARN, HDFS, log4j, and others mentioned in the External Dependencies section are Apache projects, and Weave will benefit by close proximity to them. Known Risks =========== Orphaned Products ----------------- There is very little risk of Weave being orphaned, as it is a key part of Continuuity’s products. The core Weave developers plan to continue to work on Weave, and Continuuity has funding in place to support their efforts going forward. Many other Big Data companies can benefit from Weave, and we have already received interest from various entities that would like to use and contribute to Weave. Inexperience with Open Source ----------------------------- Several of the core developers have experience with open source development. Terence Yim, Andreas Neumann and Gary Helmling are currently Apache committers for Helix, Oozie and HBase respectively Homogeneous Developers The current core developers are all Continuuity employees. However, we intend to establish a developer community that includes independent and corporate contributors. We are encouraging new contributors via our mailing lists, public presentations, and personal contacts, and we will continue to do so. Various entities have already expressed interest in becoming involved with Weave. Reliance on Salaried Developers ------------------------------- Currently, these developers are paid to work on Weave. Once the project has built a community, we expect to attract committers, developers and community other the current core developers. However, because Continuuity products use Weave internally, the reliance on salaried developers is unlikely to change, at least in the near term. Relationships with Other Apache Products ---------------------------------------- Weave is deeply integrated with Apache projects. Weave uses Apache YARN as its underlying resource management and task scheduling system and Apache Zookeeper for coordination. In addition, Weave uses Apache HDFS and Apache Kafka. A number of other Apache projects are Weave dependencies and are listed in the External Dependencies section. An Excessive Fascination with the Apache Brand ---------------------------------------------- While we respect the reputation of the Apache brand and have no doubt that it will attract contributors and users, our interest is primarily to give Weave a solid home as an open source project following an established development model. We have also given additional reasons in the Rationale and Alignment sections. Documentation ============= https://github.com/continuuity/weave Initial Source ============== The Weave codebase is currently hosted at https://github.com/continuuity/weave. External Dependencies ===================== The dependencies all have Apache-compatible licenses: • avro (Apache 2.0) • hadoop (Apache 2.0) • gson (Apache 2.0) • guava-libraries (Apache 2.0) • hbase (Apache 2.0) • hdfs (Apache 2.0) • kafka (Apache 2.0) • netty (Apache 2.0) • snappy-java (Apache 2.0) • yarn (Apache 2.0) • zookeeper (Apache 2.0) • asm (BSD) • junit (EPL v1.0) • logback (EPL v1.0 ) • slf4j (MIT) Cryptography ============ Weave will depend on secure Hadoop, which can optionally use Kerberos. Required Resources ================== Mailing Lists ------------- - weave-private for private PMC discussions (with moderated subscriptions) - weave-dev for technical discussions among contributors - weave-commits for notification about commits Subversion Directory -------------------- Git is the preferred source control system: git://git.apache.org/weave Issue Tracking -------------- JIRA Weave (WEAVE) Other Resources --------------- The existing code already has unit tests, so we would like a Hudson instance to run them whenever a new patch is submitted. This can be added after project creation. Initial Committers ================== • Terence Yim • Andreas Neumann • Gary Helmling • Poorna Chandra • Albert Shau Affiliations ============ • Terence Yim (Continuuity) • Andreas Neumann (Continuuity) • Gary Helmling (Continuuity) • Poorna Chandra (Continuuity) • Albert Shau (Continuuity) Sponsors ======== Champion -------- Vinod K <vinodkv at apache dot org> (Apache Member) Nominated Mentors ----------------- • Arun C Murthy <acmurthy at apache dot org> • Tom White <tomwhite at apache dot org> • Patrick Hunt <phunt at apache dot org> Sponsoring Entity ----------------- We are requesting that the Incubator sponsor this project.
