http://highscalability.com/blog/2010/11/4/facebook-at-13-million-queries-per-second-recommends-minimiz.html

Thursday, November 4, 2010 at 8:48AM

Facebook gave a MySQL Tech Talk where they talked about many things MySQL, but one of the more subtle and interesting points was their focus on controlling the variance of request response times and not just worrying about maximizing queries per second.

But first the scalability porn. Facebook's OLTP performance numbers were as usual, quite dramatic:

  • Query response times: 4ms reads, 5ms writes.
  • Rows read per second: 450M peak
  • Network bytes per second: 38GB peak
  • Queries per second: 13M peak
  • Rows changed per second: 3.5M peak
  • InnoDB disk ops per second: 5.2M peak

 Some thoughts on creating quality, not quantity:

  • They don't care about average response times, instead, they want to minimize variance. Every click must be responded to quickly. The quality of service for each request matters.
  • It's OK if a query is slow as long as it is always slow.
  • They don't try to get the highest queries per second out of each machine. What is important is that the edge cases are not the bad.
  • They figure out why the response time for the worst query is bad and then fix it.
  • The performance community is often focussed on getting the highest queries per second. It's about making sure they have the best mix of IOPs available, cache size, and space.

To minimize variance they must be able notice, diagnose, and then fix problems:

  • They measure how things work in operation. They can monitor at subsecond levels so they catch problems.
  • Servers have miniature fractures in their performance which they call "stalls." They've built tools to find these.
  • Dogpile collection. Every second it notices if something is wrong and ships it out for analysis.
  • Poor man's profiler. Attach GDB to servers to know what's going on, they can see when stalls happen.
  • Problems are usually counter-intuitive this can never happen type problems.
    • Extending a table locks the entire instance.
    • Flushing dirty pages was actually blocking.
    • How statistics get sampled in InnoDB.
    • Problems happen on medium-loaded systems too. Their systems aren't that loaded to ensure quality of service, yet the problems still happen.
  • Analyze and understand every layer of the software stack to see how it performs at scale.
  • Monitoring system monitors different aspects of performance so they can notice a change in performance, drill down to the host, then drill down to the query that might be causing the problem, then kill the query, and then trace it back to the source file where it occurred.
  • They have a small team, so they make very specific changes to Linux and MySQL to support their use cases. Longer term changes are made by others.

Please watch the MySQL Tech Talk for more color and details.

controlling the variance of request response times and not just worrying about maximizing queries per second的更多相关文章

  1. request response

    request 和 response 这两个对象是出现在service方法中.service方法是用来接收请求处理请求,完成响应的.     接受请求指的就是request对象     完成响应指的就 ...

  2. request \response 总结

    request&response request 1.获得信息的方法     1> 获得请求首行信息的方法         *getMethod         *getContextP ...

  3. track message forwards, avoiding request loops, and identifying the protocol capabilities of all senders along the request/response chain

    https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html The TRACE method is used to invoke a remote, ...

  4. Ng Http Request/response格式转换

    angular作为Single Page Application推荐的交互方式当然是基于json的ajax调用.但今天要说的是当你不幸工作在一个遗留或者不可控制的服务上,而这服务是基于非json提交方 ...

  5. 过滤器中的chain.doFilter(request,response)

    Servlet中的过滤器Filter是实现了javax.servlet.Filter接口的服务器端程序,主要的用途是过滤字符编码.做一些业务逻辑判断等.其工作原理是,只要你在web.xml文件配置好要 ...

  6. 对chain.doFilter(request,response)的理解

    他的作用是将请求转发给过滤器链上下一个对象.这里的“下”指的是哪里 ? 指的是下一个filter,如果没有filter那就是你请求的资源. 一般filter都是一个链,web.xml 里面配置了几个就 ...

  7. chain.doFilter(request,response)含义

    过滤器的生命周期一般都要经过下面三个阶段: 初始化 当容器第一次加载该过滤器时,init() 方法将被调用.该类在这个方法中包含了一个指向 Filter Config 对象的引用.我们的过滤器实际上并 ...

  8. ZeroMQ之Request/Response (Java)

    自己最开始是在cloud foundry中接触过消息服务器(nats),或者说是消息中间件,也算是初步知道了一个消息服务器对于分布式的网络系统的重要性,后来自己也曾想过在一些项目中使用它,尤其是在一些 ...

  9. 【转】对Django框架架构和Request/Response处理流程的分析

    本文转载于疯狂的蚂蚁. 一. 处理过程的核心概念 如下图所示django的总览图,整体上把握以下django的组成: 核心在于中间件middleware,django所有的请求.返回都由中间件来完成. ...

随机推荐

  1. ArcGIS 点到直线的距离

    /****点到直线的距离*** * 过点(x1,y1)和点(x2,y2)的直线方程为:KX -Y + (x2y1 - x1y2)/(x2-x1) = 0 * 设直线斜率为K = (y2-y1)/(x2 ...

  2. C#解决从含身份证号码的Excel表格导入数据库的问题

    用C#做从Excel表导入SQL数据库时发现从EXCEL导入的身份证号码会变成科学表示方法. 解决这个问题是比较容易的,首先,打开电子表格,选中“身份证号码”一列,右键选择“设置单元格格式”,进入单元 ...

  3. Universal JS module loader

    With dependency ;(function (root, factory) { if (typeof define === 'function' && define.amd) ...

  4. HDU2138 & 米勒拉宾模板

    题意: 给出n个数,判断它是不是素数. SOL: 米勒拉宾裸题,思想方法略懂,并不能完全理解,所以实现只能靠背模板.... 好在不是很长... Code: /*==================== ...

  5. Qt搭建多线程Server

    起因是MySQL在Android上没有驱动.也就是说,移动端想要访问远程数据库,必须通过一台(或多台)PC进行中转. 中转PC作为Server,接受来自移动端Socket访问数据库的要求,Server ...

  6. cdoj 1334 郭大侠与Rabi-Ribi Label:贪心+数据结构

    郭大侠与Rabi-Ribi Time Limit: 3000/1000MS (Java/Others)     Memory Limit: 65535/65535KB (Java/Others) 最近 ...

  7. lsof用法简介

    lsof:一个功能强大的命令 lsof命令的原始功能是列出打开的文件的进程,但LINUX下,所有的设备都是以文件的行式存在的,所以,lsof的功能很强大!  [root@limt01 ~]# lsof ...

  8. fiddler 拦截小结

    一,拦截请求或响应常用命令 1.拦截命令 bpu 清除拦截请求 bpu http://www.baidu.com 拦截访问百度网站的请求.可以在 request 框的 WebForms 中改请求内容. ...

  9. ubuntu 无声音的解决

    以下“失声疗法”是针对HDMI被设置为默认输出的情况: aplay -l 是用来查看音视频设备与卡号信息的: 然后 1.sudo gedit /etc/asound.conf 2.在文件中写入defa ...

  10. GPIO裸机编程

    作者:李老师,华清远见嵌入式学院讲师. GPIO控制技术是接口技术中最简单的一种.本章通过介绍S5PV210芯片的GPIO控制方法,让读者初步掌握控制硬件接口的方法.本章的主要内容: GPIO功能介绍 ...