See full table

The most reliable hosting company for April was Datapipe, which topped the table seven times in 2011. The company offers a wide range of hosting services and has been rapidly expanding into cloud computing during the past few months. Datapipe has infrastructure spread across the globe; they have data centres in New Jersey, San Jose, Iceland, London, Shanghai, and Hong Kong. Their U.S. data centres are powered exclusively by renewable energy sources.

For the third time so far this year INetU have taken second place. INetU offers dedicated managed hosting services and cloud hosting services from data centres in both the United States and Europe.

Choopa – a New Jersey based company advertising 100% uptime and 0% packet loss guarantees – appears in third position for the second consecutive month.

Linux was used by five of the most reliable hosting companies, including Choopa; four used FreeBSD including the most reliable, Datapipe; and the second most reliable provider, INetU, used Windows Server 2008.

Netcraft measures and makes available the response times of around forty leading hosting providers' sites. The performance measurements are made at fifteen minute intervals from separate points around the internet, and averages are calculated over the immediately preceding 24 hour period.

From a customer's point of view, the percentage of failed requests is more pertinent than outages on hosting companies' own sites, as this gives a pointer to reliability of routing, and this is why we choose to rank our table by fewest failed requests, rather than shortest periods of outage. In the event the number of failed requests are equal then sites are ranked by average connection times.

Information on the measurement process and current measurements is available.

nginx saw its 9th consecutive month of increased market share, gaining 894k hostnames and increasing its share to 5.48%, more than double the value it held a year ago. Apache fared the worst this month, losing 17.5M hostnames. However, it remains far ahead of the competition with two out of every three hostnames being served using Apache. We detected 654 hostnames using Microsoft-IIS/8.0 this month, the default web server in Microsoft's new Windows Server 2012, previously codenamed Windows Server 8.

Tracking of web servers using SPDY, an experimental network protocol intended to decrease web page loading times, has been added to the survey. We found a total of 339 SSL certificates used with SPDY-enabled servers. Usage outside of Google's properties is limited, though a few sites such as humblebundle.com and webtide.com support it. To operate, SPDY must be supported by both the web server and the user's browser. Of the major browsers, only Mozilla Firefox and Google Chrome have SPDY support. Apache, Jetty and Google's server software are currently the only servers that support SPDY, though nginx support is scheduled for the end of May 2012.

For more information see Active Sites

Apache saw the largest growth (22.8M) and increased its market share to 65.5%. nginx, with the second largest growth (4.5M), increased its total to 69.9M. Microsoft had a greater increase in hostnames this month (+3.5M) compared to March, however still experienced a small loss in market share.

Microsoft's new server operating system, codenamed Windows Server 8, which was released to MSDN subscribers in September 2011 has now been made available as a public beta. Microsoft-IIS/8.0 is the default web server on Windows Server 8, and the April 2012 survey found 278 sites with this server header. However, many of these sites are running on Linux, indicating proxy servers or forged server headers. The first sites deploying Windows Server 8 include iis.net, phponwindows.net, and a Microsoft corporate remote access service. Indicative of an early beta, many installations are on isolated broadband connections, rather than at large hosting providers.

For more information see Active Sites

See full table

Aptly named ReliableServers.com was the most reliable hosting company site in March, responding to all but one of Netcraft's requests throughout the month. The company's servers are located in seismically sound data centers in Newark and North Bergen, New Jersey, with 24/7 on-site support staff and diesel generators. Connectivity is provided by multiple fiber routes from Nlayer, Tiscali, Tinet, Level3, and extensive private peering in the NY Metro area.

In second place, with only two failed requests, was last month's winner Codero. Their dedicated servers include a 100% uptime guarantee and are hosted in Codero's own data centers in Phoenix, Arizona, Chicago and Illinois.

Linux was used by five of the most reliable hosting company sites in March, including both ReliableServers.com and Codero. Three used FreeBSD, while the remaining two were running Windows Server 2008.

Netcraft measures and makes available the response times of around forty leading hosting providers' sites. The performance measurements are made at fifteen minute intervals from separate points around the internet, and averages are calculated over the immediately preceding 24 hour period.

From a customer's point of view, the percentage of failed requests is more pertinent than outages on hosting companies' own sites, as this gives a pointer to reliability of routing, and this is why we choose to rank our table by fewest failed requests, rather than shortest periods of outage. In the event the number of failed requests are equal then sites are ranked by average connection times.

Information on the measurement process and current measurements is available.

See full table

Netcraft measures and makes available the response times of around forty leading hosting providers' sites. The performance measurements are made at fifteen minute intervals from separate points around the internet, and averages are calculated over the immediately preceding 24 hour period.

From a customer's point of view, the percentage of failed requests is more pertinent than outages on hosting companies' own sites, as this gives a pointer to reliability of routing, and this is why we choose to rank our table by fewest failed requests, rather than shortest periods of outage. In the event the number of failed requests are equal then sites are ranked by average connection times.

Information on the measurement process and current measurements is available.

Apache continued to gain hostnames this month with a growth of 22.5M and, contrary to last month, was able to increase its market share by a third of a percentage point. nginx had another good month and experienced an increase of 4.7M hostnames or 7.82%. With all other major web server vendors showing higher growth than Microsoft's 761k increase, Microsoft recorded a drop in market share of half a percentage point. The gap between Microsoft and nginx now stands at 23.6M hostnames.

Amongst the Million Busiest Sites, Apache again suffered a small drop in market share this month, losing 1,700 sites, extending a trend that dates back to August 2011. Microsoft gained 110 sites making this the first time it has recorded an increase since June 2010. nginx continued to increase its market share and gained 1.2k sites, whilst Google suffered a small loss of 289 sites.

For more information see Active Sites

See full table

Top of the table this month is Swishmail, which offers a variety of managed web hosting plans in addition to their core service of enterprise-grade email hosting.

INetU is at second place this month, which offers dedicated managed hosting services from data centres with resilient networks, backup power, and strong physical and network security. INetU also offers compliance and consultancy services to customers around the world and has recently received PCI DSS certification for their cloud service.

In third place is the California-based Multacom, which provides web hosting, dedicated servers, colocation, and managed services. Multacom's data centre is in downtown Los Angeles and offers fibre-optic links to many other carrier buildings both in Los Angeles and worldwide.

Within the top 10, Linux and FreeBSD were used by 4 hosting companies each, and Microsoft was used by 2. For the first time since July 2010, Linux was not used by any of the hosting companies in the top 4.

Netcraft measures and makes available the response times of around forty leading hosting providers' sites. The performance measurements are made at fifteen minute intervals from separate points around the internet, and averages are calculated over the immediately preceding 24 hour period.

From a customer's point of view, the percentage of failed requests is more pertinent than outages on hosting companies' own sites, as this gives a pointer to reliability of routing, and this is why we choose to rank our table by fewest failed requests, rather than shortest periods of outage. In the event the number of failed requests are equal then sites are ranked by average connection times.

Information on the measurement process and current measurements is available.

nginx was the only server to experience a non-negligible market share increase this month, gaining 0.27 percentage points. Apache did experience a growth of 19M hostnames, but its market share has remained static, while Microsoft and Google had a small drop in market share despite gaining 3.9M and 450K hostnames respectively.

Within the Million Busiest Sites nginx continued its steady growth; gaining just over 12K new sites. Apache saw the biggest loss this month with a drop of 18K hostnames.

The Resin application server has been experiencing strong growth over the past 12 months; seeing an almost tenfold growth from 480k hostnames in February 2011 to 4.7M or 0.77% of the market in February 2012. Resin is a Java application server from Caucho which is used on a number of the Million Busiest Sites, including Bebo — now recovered from its outage last week.

For more information see Active Sites

Citrix bought NetScaler Inc. in 2005 for approximately $300M in cash and stock, acquiring an already maturing network appliance platform. NetScaler provides load balancing, an application firewall, and application acceleration to improve the performance and security of large web applications. NetScaler can run on a variety of dedicated hardware platforms, or it can be run as a server-based virtual appliance. BIG-IP is a competing product from F5 with similar features which reached 10 million sites back in May 2009.

1.71% of all websites found this month were served using the Citrix NetScaler platform; but within the top 100k busiest websites NetScaler's share is much higher at 9.24%. The country distribution of the installed base has a few peculiarities: almost 30% of the websites hosted in Turkey and 20% of the websites hosted in Korea are using NetScaler. In Turkey, the blogcu.com network is using Citrix NetScaler and in Korea more than 50% of the co.cc subdomains were found to be using the platform. Worldwide, Microsoft, eBay, Weather.com, CNET, and MasterCard are among the busiest sites using Citrix NetScaler.

Bebo was previously hosted on the Akamai content delivery network, which generally increases a site's resilience to network outages and traffic spikes, but DNS lookups for the www.bebo.com website are currently not resolving:

$ ping www.bebo.com
ping: cannot resolve www.bebo.com: Host name lookup failure

$ dig www.bebo.com
; <<>> DiG 9.5.1-P3 <<>> www.bebo.com
;; global options:  printcmd
;; connection timed out; no servers could be reached

Twitter is currently awash with self-propagating rumours that Bebo has been shut down for good; however, this has been debunked by TechCrunch, which reports a Bebo spokesperson as saying the site went down due to "a technical clusterf**k". Michael Birch, who originally founded Bebo with his wife Xochi, also tweeted that the site should be coming back in a matter of hours.