WebScaleSQL 是由FB/谷歌/LinkedIn/Twitter四家公司将共享一组改编自上游MySQL的开源通用分支。 该项目包括了来自这四家公司的MySQL工程师团队的工作成果，由于它是开源的，因此其他感兴趣的个人和公司也能够基于自身的资源和规模进行定制。
Facebook公布了到目前为止，其工程师为WebScaleSQL新分支所做的改动：
面向内建测试系统的一个自动化框架，可呈现每次改动(change)、运行(run)和发布(publish)的结果； 一套完整的压力测试套件，以及一个自动化性能测试原型； 对MySQL现有测试中发现的问题架构代码做出了一些改动，以避免可能导致的失败或错误； WebScaleSQL的性能改进，包括缓冲池清洗/buffer pool flushing，对某些查询类型的优化，以及支持NUMA交错政策的支持等； 可使WebScaleSQL的true web scale更易用的新功能，如super_read_only、以及指定次秒级客户端超时时间(sub-second clients timeouts)的支持。
What is WebScaleSQL?
WebScaleSQL is a collaboration among engineers from several companies that face similar challenges in running MySQL at scale, and seek greater performance from a database technology tailored for their needs.
Our goal in launching WebScaleSQL is to enable the scale-oriented members of the MySQL community to work more closely together in order to prioritize the aspects that are most important to us. We aim to create a more integrated system of knowledge-sharing to help companies leverage the great features already found in MySQL 5.6, while building and adding more features that are specific to deployments in large scale environments. In the last few months, engineers from all four companies have contributed code and provided feedback to each other to develop a new, more unified, and more collaborative branch of MySQL.
But as effective as this collaboration has been so far, we know we’re not the only ones who are trying to solve these particular challenges. So we will keep WebScaleSQL open as we go, to encourage others who have the scale and resources to customize MySQL to join in our efforts. And of course we will welcome input from anyone who wants to contribute, regardless of what they are currently working on.
Who is behind WebScaleSQL?
WebScaleSQL currently includes contributions from MySQL engineering teams at Alibaba, Facebook, Google, LinkedIn, and Twitter. Together, we are working to share a common base of code changes to the upstream MySQL branch that we can all use and that will be made available via open source. This collaboration will expand on existing work by the MySQL community, and we will continue to track the upstream branch that is the latest, production-ready release (currently MySQL 5.6).
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https://github.com/webscalesql/webscalesql-5.6