Skip to main content

Get the best research tool on the web today,and free!
Connect with people with common interests!

Play Webslides

Joel Liu's Bookmarks tagged Architecture → View Popular

You are here: Diigo Home > Joel Liu's Bookmarks

Ads by Google

Expand All 1 - 17 of 17

5Expand

Gojko Adzic » QCon London 2009: Upgrading Twitter without service disruptions

Tags: twitter, architecture, Performance on 2009-07-03 and saved by 5 people -All Annotations (6) -About

more fromgojko.net

A very interesting observation during the talk was that Twitter started up with a CMS model and that they gradually moved towards a messaging model. I’ve seen this in a few applications so far, including a casino system, where the messaging model seems to fit best an application intended to power massive community of online users, it seems regardless of what the application actually does business wise. Applications start out completely different, but then more and more functionality gets bolted on top of user messaging capabilities that the whole architecture on the end gets refactored to utilise the messaging channels as the core information transport. With Twitter, I’d expect this to be more obvious from the start as it was intended to help people notify each other.
The interesting thing, however, was that all the upgrades were done live, without shutting down the system. The changes were always introduced to one node, then regression issues were sorted out, and then the software would be rolled out to the whole cluster. They went as far as building a whole messaging system based on memcached APIs in order to be able to slot in such changes.
a write-through vector cache of primary tweet keys with 99% hit ratio, a write-through row cache for tweets and users with 95% hit rate and a read-through fragment cache with rendered versions of different tweets for different clients with 95% hit rate. All these caches are based on memcached.
this change allowed them to increase the web server performance from 3.32 requests per second without caching to 139.03 requests per second. Weaver said that API services work about four times faster than the web, which means that the API performance is roughly 550 requests/s [my calculation, not given during the talk].
- Web is only 10-20% of the traffic, the rest is through API services
- Web servers are still 50% of the cluster.
- Regular incoming traffic peaks are around 80 tweets per second. I expected this to be a lot more.
- before the upgrades their web servers shipped only 3.32 requests per second!
- For each tweet, message gets inserted for each user which follows a tweet. In average, a user has 120 followers so this comes to about 9600 messages/s at peak times
- Message servers run on three nodes. They decided to write their own messaging software in order to make the protocol memcached-like, and did not evaluate other available solutions.
- During Obama’s inauguration, they peaked at about 350 tweets per second for around five minutes.
- They had a ton of problems with garbage collection but strangelly haven’t looked into JRockit RT or something similar that has predictable GC. Twitter JVM middleware runs on the SUN JVM

3Expand

InfoQ: Twitter, an Evolving Architecture

Tags: twitter, architecture, Performance on 2009-07-03 and saved by 13 people -All Annotations (3) -About

more fromwww.infoq.com

Drop ACID and Think About Data | High Scalability

Tags: database, scalability, Architecture on 2009-05-10 and saved by 9 people -All Annotations (2) -About

more fromhighscalability.com

1Expand

GoogleTalk Architecture | High Scalability

Tags: Scalability, Architecture, google, talk, IM on 2009-05-10 and saved by 4 people -All Annotations (1) -About

more fromhighscalability.com

The Anatomy of a Search Engine

Tags: google, search, architecture on 2009-05-10 and saved by 49 people -All Annotations (142) -About

more frominfolab.stanford.edu

Facebook | Engineering @ Facebook's Notes

Tags: facebook, Architecture, photo, storage on 2009-05-02 and saved by 7 people -All Annotations (2) -About

more fromwww.facebook.com

1Expand

Elven Architecture at amdev

Tags: Architecture on 2009-04-25 -All Annotations (1) -About

more fromamromousa.com

Cookies are for Closers: Oren Hurvitz’s Blog » LinkedIn Architecture

Tags: Scalability, Architecture on 2008-07-03 and saved by 18 people -All Annotations (1) -About

more fromhurvitz.org

Friends for Sale Architecture - A 300 Million Page View/Month Facebook RoR App | High Scalability

Tags: architecture, facebook, scalability on 2008-02-22 and saved by 22 people -All Annotations (2) -About

more fromhighscalability.com

Architectural Styles and the Design of Network-based Software Architectures

Tags: architecture, design, programming, software on 2008-01-25 and saved by 89 people -All Annotations (0) -About

more fromwww.ics.uci.edu

1Expand

ArchitectNotes - Varnish - Trac

Tags: architecture, varnish on 2007-12-27 and saved by 6 people -All Annotations (0) -About

more fromvarnish.projects.linpro.no

Nati Shalom's Blog: Architecture You Always Wondered About: Lessons Learned at Qcon

Tags: architecture on 2007-11-16 and saved by 2 people -All Annotations (0) -About

more fromnatishalom.typepad.com

YouTube - Androidology - Part 1 of 3 - Architecture Overview

Tags: android, architecture on 2007-11-12 and saved by 2 people -All Annotations (0) -About

more fromwww.youtube.com

Peeking Into Google

Tags: architecture, google, server on 2006-11-23 and saved by 29 people -All Annotations (3) -About

more fromwww.internetnews.com

High-Performance Server Architecture

Tags: architecture, server on 2006-11-23 and saved by 20 people -All Annotations (1) -About

more frompl.atyp.us

KarKomaOnline - Implementing High Availability in MySQL

Tags: architecture, backup, mysql on 2006-03-02 and saved by 9 people -All Annotations (0) -About

more fromwww.karkomaonline.com

1Expand

SEDA - Architecture for Highly-Concurrent Server Applications

Tags: architecture, concurrent, scalability, server, to_research on 2006-03-02 and saved by 30 people -All Annotations (5) -About

more fromwww.eecs.harvard.edu

1 - 17 of 17

List 20 50 100

Notation: * = Private bookmark and comment|… = Clipping [?] | … = Public highlight [?]

Joel Liu's Related Tags

Selected tags

Architecture

Related tags

See More Top Contributors

Ako Z°om arc_room brian rodney shireen craig hancock Jean-Louis ZIMMERMANN

Related Groups on Diigo

IT architecture

Members (16)

bookmarks (121)
Future Architecture

Members (16)

bookmarks (177)
tout_Liege

Members (1)

bookmarks (1124)