Website Down?!

Website down?! Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds 3 days 15 hours 36 minutes O seconds %0 66 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions down?! Website Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT 中 中 Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 2 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds %0 66 3 days 15 hours 36 minutes O seconds 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions down?! Website Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT 中 中 Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 2 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds %0 66 3 days 15 hours 36 minutes O seconds 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions down?! Website Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT 中 中 Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 2 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds %0 66 3 days 15 hours 36 minutes O seconds 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions down?! Website Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT 中 中 Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 2 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds %0 66 3 days 15 hours 36 minutes O seconds 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions down?! Website Types, causes and results of failures infographic created by website-monitoring.com Website did not work for 5 minutes Greatest losses How much would the biggest online sellers lose, if their websites did not work for 5 minutes. Seller Losses amazon.com $325 342 50 staples.com $97.031.96 apple.com $49,728 88 dell.com $45.679.22 officedepot.com $39.003 04 walmart.com $38 955 48 sears.com $29 558.08 libertymedia.com $28 919.33 officemax.com $27,193.94 Based on the 2010 data. cdw.com $25,847.87 And how much would You lose? Symptoms of a website failure The browser cannot find the page Timeout It seems that the page is takes a lot of time and nothing is displayed. This a problem with the domair (e.g. expiry) or DNS server. but it Server not found Try Again Error message Error 404 Page not found The server displays a three-digit error number and its description. (see Server error codes below) The page is displayed incorrectly Functionalities do not work E.g. some content or images are missing or everything is shifted. E.g. a contact or registration form. Page Login Nick: Nick Pass: no img Try Again Types of website failures Network failures The page is unavailable because of a link failure. This refers mainly to the links on the internet server side. Problems with other links - between operators and on the user side - make the website unavailable only for some users and are not treated as a failure. One of the network failures is also the DNS server configuration error. Hardware failures Website unavailability is caused by damage to one of the server units, e.g. the hard disk. One of the hardware failures is also the data centre failure, e.g. a power supply failure. System failures Website malfunctioning results from misconfiguration of the server, #@* *& *&#!@ its operating system or the installed software. One of the system failures is also the failure connected with databases. Page Application failures Errors in the construction of the website itself causing its malfunc- tioning. Efficiency failures The traffic exceeds the infrastructure (server and link) capacity and the page cannot be displayed to all users. This most often signifies an unexpected surge in the website's popularity. Server error codes The most common http error codes and their meanings. 401 401 Unauthorized Authentication has failed or not yet been provided. Unauthorized 403 Forbidden 403 The request was a legal request, but the server is refusing to respond to it. Forbidden 404 Not Found 404 The requested resource could not be found but may be available again in the future. Not Found 500 Internal Server Error 500 Internal Server Error A generic error message, given when no more specific message is suitable. 502 Bad Gateway 502 The server was acting as a gateway or proxy and received an invalid response from the upstream server. Bad Gateway 503 Service Unavailable 503 Service Unavailable The server is currently unavailable (because it is overloaded or down for maintenance). Causes of website failures Human error Hardware wearing out The root of application and system errors and less frequently hardware errors. Mechanical elements (e.g. traditional hard disks) have a limited life cycle. As is the case with people - some die earlier These are unintentional failures which are most easily repaired. and some die later. Retired! Random Intentional Impossible to be foreseen, e.g. a failure of These are usually planned shutdowns where it is impossible that each and every user is informed. However, these are also hacker attacks. a new hard disk from a renowned producer. These also result from natural catastro- phes, burglaries where hardware is stolen etc. Results of website failures No sale made Financial consequences of a failure are most evident in the case of e-commerce websites. Lost leads Potential clients will not wait and will go to the competition. Wasted budget of the campaign The money spent on the advertising goes down the drain when the users do not land on a working website. No ads displayed The website which eams through advertising will earn less when no adverts are shown during the failure. EXIT 中 中 Dissatisfied clients If an online customer service fails, even the most loyal clients may desert. Damaged image A failing website will be noticed by journalists, partners, providers and employees. Consequences for SEO Search engines may downgrade the website in the rankings, if it is often unavailable. Operational problems If any business processes are run through the website, negative effects may affect various aspects of company operations. Lost impressions The number of page views lost during a 5-minute outage. Website did not work for 5 minutes 1.200 1158 1,000 800 600 579 400 290 200 116 58 2 12 29 1,000,000 Monthly website traffic (PV) 1,000 10,000 500,000 100,000 250,000 2,500,000 5,000,000 10,000,000 How to prevent and respond? 1. Do not economise on hosting Choose a reliable provider with an established position on the market which has serviced some renowned clients and offers the highest possible SLA level (Service Level Agreement - minimum availability guarantee). 2. Sign a service agreement for the website Even if you administer the content on your own using a CMS, provide yourself with support and readiness of webmasters who will be able to quickly repair your website in a critical moment. 3. Monitor your website Use monitoring services which will check your website's availability (and also check the content, test forms and measure the loading time), immediately inform you about failures and report a monthly availability level - to be compared with the one set out in the agreement (SLA). 4. Report failures It is not true that webmasters and hosting providers always learn about every failure as the first. If they do not use external monitoring services, they often leam about the problems from their clients. 5. Demand compensation Only some hosting providers inform their clients about the total unavailability time at the end of the month. And although they may offer compensation for their failure to meet SLA levels, it is really rarely the case that they pay it without their client's request. SLA SLA levels and acceptable unavailability times in a year. 8 hours 45 minutes 36 seconds 99,8% 17 hours 31 minutes 12 seconds 99,7% 1 day 2 hours 16 minutes 48 seconds 99.6% 1 day 11 hours 2 minutes 24 seconds 99,5% 1 day 19 hours 48 minutes 0 seconds 99,4% 2 days 4 hours 33 minutes 36 seconds 99,3% 2 days 13 hours 19 minutes 12 seconds 99,2% 2 days 22 hours 4 minutes 48 seconds 99,1% 3 days 6 hours 50 minutes 24 seconds %0 66 3 days 15 hours 36 minutes O seconds 98,0% 7 days 7 hours 12 minutes 0 seconds 97,0% 10 days 8 hours 45 minutes 36 seconds infographic created by Website down?! website-monitoring.com Types, causes and results of failures Sources: wikipedia.org, internetretailer.com Lost impressions