Social network downtime in 2008 February 2009 This is a survey of the 2008 website availability (uptime) of 15 of the world s largest social networks. It includes analysis of the accumulated downtime of each social network over the entire year, a look at the longest outages, a detailed month-by-month breakdown of the downtime for each website, and a trend analysis looking at how much of the downtime took place during each quarter of 2008.
Social network downtime in 2008 February 2009 Contents Introduction... 3 Why high availability is important to social networks... 4 Social network downtime in 2008... 5 Key findings... 5 The longest outages... 6 Month-by-month and quarterly breakdown per social network... 7 Twitter... 8 LinkedIn... 9 Friendster... 10 Reunion.com... 11 Bebo... 12 Hi5... 13 Windows Live Spaces... 14 LiveJournal... 15 Last.fm... 16 Orkut... 17 Facebook... 18 MySpace... 19 Classmates.com... 20 Xanga... 21 Imeem... 22 Conclusion... 23 Methodology... 24 2
1 http://blog.facebook.com/blog.php?post=46881667130 Introduction Social networks (and social media in general) have become a true force to be reckoned with on the Web. Many have millions of users, and some even count their user base in the tens of millions. As an extreme example, Facebook recently passed 150 million users 1. The massive amount of traffic and data that social networks handle pose unique challenges to these sites, challenges that must be met to keep providing a useful and popular service to their users. These social networks are global affairs, so any downtime they have will affect their users no matter what time of the day it is. There will always be time zones where it is daytime. This report looks at the site uptime (availability) of 15 different social networks to see how they have handled their uptime during 2008. Also examined is the downtime/uptime trend for each of the included social networks as well as the longest outages for each, with added commentary where it is suitable. 2 http://www.facebook.com/ 3 http://www.myspace.com/ 4 http://www.linkedin.com/ 5 http://www.twitter.com/ 6 http://www.friendster.com/ 7 http://www.livejournal.com/ 8 http://www.orkut.com/ 9 http://www.bebo.com/ 10 http://www.hi5.com/ 11 http://spaces.live.com/ 12 http://www.last.fm/ 13 http://www.classmates.com/ 14 http://www.reunion.com/ 15 http://www.xanga.com/ 16 http://www.imeem.com/ The social networks included in this report are: Facebook 2, MySpace 3, LinkedIn 4, Twitter 5, Friendster 6, LiveJournal 7, Orkut 8, Bebo 9, Hi5 10, Windows Live Spaces 11, Last.fm 12, Classmates.com 13, Reunion.com 14, Xanga 15 and Imeem 16. 3
Why high availability is important to social networks High availability is important to all websites, and the more users they have, the more users are affected by downtime issues. Here are some more reasons in addition to pure size why uptime really matters to social networks. Frequent usage Users of social networks access the site frequently and have many page views per visit, which increases the chance that they will be affected by outages. 1 http://royal.pingdom.com/2007/04/27/there-is-no- %E2%80%9Cin-the-middle-of-the-night%E2%80%9D-onthe-web/ Global user base There simply is no in the middle of the night on the Web 1. Downtime at 4 a.m. on the US East Coast may not bother most American site visitors, but that is 10 a.m. in central Europe, and 8 p.m. in Sydney, Australia. Reputation A lot of downtime can lead to discussion about site issues rather than the positive aspects of a service. And since this is social media, news about outages and problems can spread like wildfire across the Web. After all, much of social media is about communicating, and users will communicate to the world if they are unhappy with a service (even if it is free). This is the flip side of user goodwill. User retention Users will flee a service that they are consistently unhappy with, and frequent downtime can be a reason for this. 2 http://money.cnn.com/2007/08/22/technology/facebook_ economy.biz2/index.htm Dependent third parties In many ways, social networks have become platforms for third-party content, and there are whole businesses based on this concept. This is often referred to as the Facebook economy, but essentially applies to other social networks as well 2. All social networks that allow third-party content being served to its users directly affect the income of those third parties if the service is unavailable. 4
Social network downtime in 2008 This is a summary of the accumulated downtime in 2008 for each of the 15 social networks included in this survey. Note the Key Findings section directly below the chart to get some additional perspectives on the data. Social network downtime in 2008 Social network downtime in 2008 * Note that Imeem was not added for monitoring until May 9, 2008 and thus has incomplete data. Key findings There are a lot of interesting observations to be made when analyzing all the data in this report. Below we have included a list of some of the standout facts and trends in social network site availability in 2008. Facebook and MySpace, the two giants in this test, both had very little downtime in 2008. Only 5 social networks managed an overall uptime of 99.9% or better: Facebook (99.92%), MySpace (99.94%), Classmates.com (99.95%), Xanga (99.95%) and Imeem (99.95%). Again, it should be pointed out that Imeem was only monitored from May 9 and onward while the other sites were monitored the entire year. 1 http://royal.pingdom.com/2008/11/14/massive-downtimefor-friendster-today-and-yesterday/ 2 http://royal.pingdom.com/2008/11/19/livejournal-moves-tonew-server-facility/ 3 http://royal.pingdom.com/2008/10/10/is-linkedin-havingscaling-issues/ The single most massive social network incident in 2008 happened to Friendster. The service had a data center outage in November that caused more than 23 hours of downtime in a time span of less than 3 days. If it weren t for that incident, Friendster would have placed much better in this survey 1. 84% of Twitter s downtime happened during the first half of 2008. July and onward has seen a big improvement in site availability for Twitter. 77% of LiveJournal s downtime happened in Q4 of 2008. It is too early to say if this is indicative of a trend or if it was a temporary lapse in uptime due to the service s migration to a new hosting provider 2. LinkedIn s downtime has been increasing over the year. Each quarter has seen a larger amount of downtime than the one before it. 63% of its downtime took place during the second half of 2008 3. 5
The longest outages Over a year, downtime adds up. In some cases most of the downtime is caused by a few longer outages, and in some other cases the majority of the downtime comes from brief outages, sometimes only lasting a few minutes each. Brief periods of downtime lasting 5-30 minutes are common among websites, and social networks are no exception. The longest continuous outages that we recorded for each website are listed here below. As you can see, the differences are quite large, though it doesn t necessarily correspond to the overall amount of downtime across the whole year. This is due to the effect of accumulated, smaller outages that make up a large portion of the downtime for many of the sites in the survey. Longest continuous outage (hours) Longest continuous outage (hours) When the longest outages happened Social network Longest continuous outage (hours) Start date for longest outage Reunion.com 9.9 March 29 Orkut 8.8 July 21 Friendster 8.1 November 13 Windows Live Spaces 6.0 February 14 LinkedIn 5.4 September 6 When the longest outages happened LiveJournal 2.8 November 18 Twitter 2.5 April 4 Last.fm 2.5 April 18 Bebo 1.6 June 14 MySpace 1.4 June 8 Hi5 1.3 April 24 Xanga 1.0 December 23 Imeem 1.0 November 21 Classmates.com 0.7 July 2 Facebook 0.4 July 14 6
Month-by-month and quarterly breakdown per social network This is a breakdown to downtime per month for each social network, with added commentary where necessary to explain trends or certain specific outages of interest. To make it easier to see trends we have also added a graph showing how much of the total yearly downtime took place during each quarter. Included is also the overall yearly uptime percentage for each site. 7
Twitter Overall uptime 2008: 99.04% While Twitter did have the most downtime among the social networks in this report when you look at the year as a whole, it should be noted that 84% of this downtime came during the first half of 2008. July onward, Twitter has suffered significantly less downtime compared to earlier, which is easy to see in these diagrams. Monthly downtime for Twitter in hours Downtime per quarter for Twitter 8
LinkedIn Overall uptime 2008: 99.48% LinkedIn seems to be on a trend toward increasing amounts of downtime, as can be seen in the month-by-month diagram below, and even clearer in the quarterly breakdown. 63% of its downtime took place during the second half of 2008. Monthly downtime for LinkedIn in hours Downtime per quarter for LinkedIn 9
Friendster Overall uptime 2008: 99.50% The spike in downtime that Friendster suffered in November was due to an outage at Friendster s hosting provider on November 13. The site was not completely restored until several days later, suffering a total of 23 hours of downtime in a 3-day period. Monthly downtime for Friendster in hours Downtime per quarter for Friendster 10
Reunion.com Overall uptime 2008: 99.52% The major reason for the downtime spike for Reunion.com in March was an outage that lasted almost 10 hours, starting on the evening of March 29, US time. Monthly downtime for Reunion.com in hours Downtime per quarter for Reunion.com 11
Bebo Overall uptime 2008: 99.56% Bebo has not had any long single outages (the longest lasted just over an hour, in August). The months with more downtime simply have a larger amount of short outages (usually lasting 5-25 minutes). Monthly downtime for Bebo in hours Downtime per quarter for Bebo 12
Hi5 Overall uptime 2008: 99.75% The main reason for the downtime peak in April was more than 3 hours of downtime (two hour-long outages and a few shorter ones) on April 24 and 25, and some additional, shorter outages spread over the rest of the month. Monthly downtime for Hi5 in hours Downtime per quarter for Hi5 13
Windows Live Spaces Overall uptime 2008: 99.81% The spike in downtime in February was caused by a 6-hour outage on February 14. The downtime in December was isolated to December 3, when an hourlong outage and several shorter ones (lasting 5-20 minutes each) had the site unavailable for 3 hours and 30 minutes that day. Monthly downtime for Windows Live Spaces in hours Downtime per quarter for Windows Live Spaces 14
LiveJournal Overall uptime 2008: 99.82% LiveJournal has seen a sharp increase in downtime from October and onward. In fact, 77% of LiveJournal s downtime for the entire year took place in Q4. It remains to be seen if this is something temporary or an actual trend. The downtime in October was mainly due to hour-long outages on October 3, October 26 and October 27. The downtime in November was mainly due to an almost 3-hour outage on November 18 in addition to an hour-long outage on November 26. The majority of the December downtime took place on December 30. 1 http://royal.pingdom.com/2008/11/19/livejournal-moves-tonew-server-facility/ The outage on November 18 was due to a data center migration 1. Monthly downtime for LiveJournal in hours Downtime per quarter for LiveJournal 15
Last.fm Overall uptime 2008: 99.86% The main reason for the downtime spike in April was an outage that lasted 2 hours and 30 minutes on April 18. Monthly downtime for Last.fm in hours Downtime per quarter for Last.fm 16
Orkut Overall uptime 2008: 99.87% 1 http://en.blog.orkut.com/2008/07/update-on-recent-orkutmaintenance.html The downtime spike in July was due to an outage lasting 7 hours and 40 minutes on July 21 (in the evening, US time). That outage was due to Google disabling Orkut to fix a bug in the system 1. Monthly downtime for Orkut in hours Downtime per quarter for Orkut 17
Facebook Overall uptime 2008: 99.92% Facebook s uptime improved during the second half of 2008. Both October and December saw 100% uptime. 68% of Facebook s downtime happened in the first half of 2008. Facebook didn t have any single continuous outage lasting longer than 25 minutes in 2008. Monthly downtime for Facebook in hours Downtime per quarter for Facebook 18
MySpace Overall uptime 2008: 99.94% The downtime spike in June was mainly caused by an outage lasting 1 hour and 25 minutes on the morning of June 8, US time. Just like Facebook, MySpace s uptime improved during the second half of 2008. Monthly downtime for MySpace in hours Downtime per quarter for MySpace 19
Classmates.com Overall uptime 2008: 99.95% The downtime peak in February was made up of two half-hour outages and a couple of briefer ones on February 9. Monthly downtime for Classmates.com in hours Downtime per quarter for Classmates.com 20
Xanga Overall uptime 2008: 99.95% The increased downtime in December was caused by an hour-long outage on December 23. Monthly downtime for Xanga in hours Downtime per quarter for Xanga 21
Imeem Overall uptime 2008: 99.95% Imeem was included in the survey from May 9, 2008, and onward. Therefore we have no data of their availability before that date. All the other social networks in the survey were monitored for the entire period (2008). The increase in downtime in November was mainly due to an hour-long outage on November 21. Monthly downtime for Imeem in hours Downtime per quarter for Imeem 22
Conclusion It would seem that the single largest challenge to the social networks in this survey is the sheer scale on which they operate. This is a challenge that all large websites face, but the intense usage and amounts of data that have to be handled simply make it an exceptional challenge. Bandwidth, storage, data processing, web page generation, all become potential bottlenecks. This survey has shown that during these circumstances, even the most established players such as Facebook and Myspace will have occasional downtime, and it also shows that site availability changes over time for most sites. Some reasons for trends involving more downtime can for example be scalability issues due to growth of the user base, or the switch to a different service provider. Some reasons for improved uptime (less downtime) can be that new, more stable technologies are adopted, or switching to a different service provider. These are all continuous challenges that all social networks (and all websites) need to deal with. 23
Methodology 1 http://www.pingdom.com/ All the monitoring was done using the Pingdom uptime monitoring service 1, which tests sites from multiple locations in both Europe and North America. All monitoring was done by loading the homepage for each social network. For example, www.facebook.com. No logins were performed. Tests were performed every 5 minutes. The criteria for counting a website as down were as follows: If the site was unreachable. If the web page could not load within 30 seconds (only the HTML part of the page). If the web page responded with an HTTP error, for example HTTP error 404 (page not found) or 500 (internal server error). Downtime had to be confirmed from two different locations for it to count. A side effect of these criteria is that some downtime due to maintenance may have been missed, if the site put up a replacement page that could be loaded in combination with not reporting an HTTP error. This can normally be worked around by checking for specific strings on a page, but due to the more general monitoring done here this was outside the scope of this survey. 24
About this report This report was created entirely by Pingdom. All monitoring was done using Pingdom s own monitoring network, using separately set up monitoring of the websites involved. No data from any customer accounts has been used. This is an open report. We encourage you to share it, but if you quote its content, please credit Pingdom as the source, preferably with a link to www. pingdom.com. Thank you. If you have any questions regarding this report, please don t hesitate to contact us at: info@pingdom.com About Pingdom Pingdom is an uptime monitoring service headquartered in Sweden. The service makes it possible for its customers to monitor the availability and response time of websites and servers on the Internet from multiple locations across the world. The resulting monitoring data can be analyzed online with the help of various reports, and users can receive alerts via email and SMS as soon as errors are detected, for example when a website becomes unreachable. Pingdom has customers in 131 countries, and is one of the fastest growing and most popular uptime monitoring services in the world. Visit us at: www.pingdom.com Disclaimer This report comes with no warranty. The information in this report is delivered to you as is and Pingdom makes no warranty as to its accuracy or use. Inaccuracies as a result of typographical or other errors are possible. Pingdom AB Stansargrand 4 721 30 Vasteras Sweden Call us: Within US: +1-212-796 689 0 International: +46-21-480 09 20 Email: info@pingdom.com Web: www.pingdom.com