+1 (non binding) I've used Curator in the past and I'm happy to see this project joining the foundation.
-- Andrei Savu On Tue, Feb 26, 2013 at 1:14 AM, Jordan Zimmerman < jor...@jordanzimmerman.com> wrote: > Hello, > > I would like to propose that Curator to be an Apache Incubator project. > > The proposal can be found here: > http://wiki.apache.org/incubator/CuratorProposal > > I have included the contents of the proposal below. > > Sincerely, > > Jordan Zimmerman > > =================== > > = Curator - ZooKeeper client wrapper and rich ZooKeeper framework = > > == Abstract == > > Curator is a set of Java libraries that make using Apache ZooKeeper much > easier. While ZooKeeper comes bundled with a Java client, using the client > is non-trivial and error prone. > > == Proposal == > > Curator is a set of Java libraries that make using Apache ZooKeeper much > easier. While ZooKeeper comes bundled with a Java client, using the client > is non-trivial and error prone. It consists of three components that build > on each other. Curator Client is a replacement for the bundled ZooKeeper > class that takes care of some low-level housekeeping and provides some > useful utilities. Curator Framework is a high-level API that greatly > simplifies using ZooKeeper. It adds many features that build on ZooKeeper > and handles the complexity of managing connections to the ZooKeeper cluster > and retrying operations. Curator Recipes consists of implementations of > some of the common ZooKeeper “recipes”. Additionally, Curator Test is > included which includes utilities to help with unit testing ZooKeeper-based > applications. > > == Background == > > Curator was initially developed by Netflix to make writing ZooKeeper-based > applications easier and more reliable. Curator was open-sourced by Netflix > on !GitHub as an Apache 2.0 licensed project in July 2011. During this time > Curator has been formally released many times and has gained widespread > adoption. > > == Rationale == > > New users of ZooKeeper are surprised to learn that a significant amount of > connection management must be done manually. For example, when the > ZooKeeper client connects to the ensemble it must negotiate a new session, > etc. This takes some time. If you use a ZooKeeper client API before the > connection process has completed, ZooKeeper will throw an exception. These > types of exceptions are referred to as “recoverable” errors. > Curator automatically handles connection management, greatly simplifying > client code. Instead of directly using the ZooKeeper APIs you use Curator > APIs that internally check for connection completion and wrap each > ZooKeeper API in a retry loop. Curator uses a retry mechanism to handle > recoverable errors and automatically retry operations. The method of retry > is customizable. Curator comes bundled with several implementations > (ExponentialBackoffRetry, etc.) or custom implementations can be written. > > The ZooKeeper documentation describes many possible uses for ZooKeeper > calling each a “recipe”. While the distribution comes bundled with a few > implementations of these recipes, most ZooKeeper users will need to > manually implement one or more of the recipes. Implementing a ZooKeeper > recipe is not trivial. Besides the connection handling issues, there are > numerous edge cases that are not well documented that must be considered. > For example, many recipes require that an ephemeral-sequential node be > created. New users of ZooKeeper will not know that there is an edge case in > ephemeral-sequential node creation that requires you to put a special > “marker” in the node’s name so that you can search for the created node if > an I/O failure occurs. This is but one of many edge cases that are not well > documented but are handled by Curator. > > = Current Status = > > == Meritocracy == > > Curator was initially developed by Jordan Zimmerman in 2011 at Netflix. > Developers external to Netflix provided feedback, suggested features and > fixes and implemented extensions of Curator. Netflix's engineering team has > since maintained the project and has been dedicated towards its > improvement. Contributors to Curator include developers from multiple > organizations around the world. Curator will be a meritocracy as it enters > the Incubator and beyond. > > == Community == > > Curator is currently used by a number of organizations all over the world. > Curator has an active and growing user and developer community with active > participation in the [[http://groups.google.com/group/curator-users]] > mailing list and at its !Github home: [[ > https://github.com/Netflix/curator]]. > > Since open sourcing the project, there have been fifteen individuals from > various organizations who have contributed code. > > == Core Developers == > > The core developers for Curator are: > * Jordan Zimmerman > * Jay Zarfoss > > Jordan has contributed towards Apache ZooKeeper and both Jordan and Jay > are familiar with Apache principles and philosophy for community driven > software development. > > == Alignment == > > Curator is a natural complement for Apache ZooKeeper. Java users of > ZooKeeper will naturally want to use Curator. When Curator graduates from > Incubator it may be useful to distribute Curator artifacts as part of > ZooKeeper releases as the preferred/recommended client side library. > Further, at graduation a determination can be made as to whether Curator > should become a Top Level Project or be merged into ZooKeeper itself. > > = Known Risks = > > == Orphaned Products == > > Curator is already deployed in production at multiple companies and they > are actively participating in creating new features. Curator is getting > traction with developers and thus the risks of it being orphaned are > minimal. > > == Inexperience with Open Source == > > All code developed for Curator has been open sourced by Netflix under > Apache 2.0 license. All committers to Curator are intimately familiar with > the Apache model for open-source development and are experienced with > working with new contributors. > > == Homogeneous Developers == > > The initial committers are from a single organization. However, we expect > that once approved for incubation, the project will attract new > contributors from diverse organizations and will thus grow organically. The > submission of patches from developers from several different organizations > is a strong indication that Curator will be widely adopted. > > == Reliance on Salaried Developers == > > It is expected that Curator will be developed on salaried and volunteer > time, although all of the initial developers will work on it mainly on > salaried time. > > == Relationships with Other Apache Products == > > Curator depends upon other Apache Projects: Apache ZooKeeper, Apache > Log4J, and multiple Apache Commons components. Its build depends upon > Apache Maven. Notably, there is interest from other Apache Projects such as > HBase in adopting Curator as the client library for ZooKeeper. Apache James > Mailbox has already incorporated Curator. > > == An Excessive Fascination with the Apache Brand == > > We would like Curator to become an Apache project to further foster a > healthy community of contributors and consumers around the project. Since > Curator directly interacts with Apache ZooKeeper and solves an important > problem of many ZooKeeper users, residing in the Apache Software Foundation > will increase interaction with the larger community. > > = Documentation = > > * Curator wiki at GitHub: https://github.com/Netflix/curator/wiki > * Curator issues at GitHub: https://github.com/Netflix/curator/issues > * Curator javadoc at GitHub: http://netflix.github.com/curator/doc/ > > = Initial Source = > > * git://github.com/Netflix/curator.git > > == Source and Intellectual Property Submission Plan == > > * The initial source is already licensed under the Apache License, > Version 2.0. https://github.com/Netflix/curator/blob/master/LICENSE.txt > > == External Dependencies == > > The required external dependencies are all Apache License or compatible > licenses. Following components with non-Apache licenses are enumerated: > > * org.slf4j: MIT-like License > * org.mockito: MIT-like License > > == Cryptography == > > Curator contains no known cryptography. > > = Required Resources = > > == Mailing lists == > > * curator-private (with moderated subscriptions) > * curator-dev > * curator-commits > * curator-user > > == Github Repositories == > > http://github.com/apache/curator git://git.apache.org/curator.git > > == Issue Tracking == > > JIRA Curator (CURATOR) > > == Other Resources == > > The existing code already has unit and integration tests so we would like > a Jenkins instance to run them whenever a new patch is submitted. This can > be added after project creation. > > = Initial Committers = > > * Jordan Zimmerman (jzimmerman at netflix dot com) > * Jay Zarfoss (jzarfoss at netflix dot com) > > = Affiliations = > > * Jordan Zimmerman, Netflix > * Jay Zarfoss, Netflix > > = Sponsors = > > == Champion == > > * Patrick Hunt > > == Nominated Mentors == > > * Patrick Hunt > * Enis Söztutar > * Mahadev Konar > > == Sponsoring Entity == > > * Apache Incubator PMC
