What sort of person would find this site useful?

• Someone who runs an application based site. Normally this has some sort of content management system built in. These can have reload delays if they aren't visited regularly. (This site is run on DotNetNuke and is kept alive by itself)
  
• Someone who runs any type of website but wants to monitor the amount of uptime and downtime the site is experiencing, or the general health of the site.
• A friend of mine even uses it to monitor his clients internet connections. They each have IIS installed serving up remote working login pages. He was able to spot and investigate anomaly's in connection speed from the traces PingAlive produced.

How does PingAlive work?

• It basically visits the sites you set up, pretty much as if they were accessed by a browser on someone's computer. It monitors the time it takes to get a response back, or the error raised. It logs this information for later analysis and if response times or errors don't fit in with a target you set it alerts you via email if you wish.

How often does PingAlive visit my sites?

• At the moment it visits them once every 2 minutes.

What do you classify as a timeout?

• Any response over 30 seconds is taken as a timeout.

What is the TARGET setting for?

• This is used to set a response time target for your site. It defaults to 1 second which should be fine for most cases. If your site consistently responds slower than your target then it's notional health starts to deteriorate.

What does the Sensitivity setting do?

• This adjusts how quickly your sites health will deteriorate. The lower the value the less deterioration.
  
  

How does health work?

• There are two healths calculated; a short term health and a long term health which are both calculated similarly.
• Every time the response time doesn't meet your target both health values increase (higher health value is worse).
• The amount they increase varies depending on whether the response missed the target by a little or by a lot. Also, if an error occurs then a lot is added to both values. The sensitivity affects this too.
• If your target is met, then the healths decrease. In the case of the short term health it decreases by around 15%, while the long term health only decreases by 1%.
• Once short term health gets to 40 the site is at amber status and at 90 it is at red status. Anything below 40 is thought of as green status. Ideally you want the health at zero almost constantly.
• If a site runs into problems and maxes out both healths then it takes approximately 30 minutes to get back to green status for short term health and around 24 hours for long term health.

I am getting spammed by messages about one of my sites, what can i do?

• Make sure you have set a realistic target for the site; there's no point in setting a 500ms target if your site takes 1000ms to respond 20% of the time. Once you have logged some response times, adjust your target accordingly.
• Some sites / servers / hosts are just plain bad and the response time is all over the place. I've seen sites take anywhere from 200ms to 30000ms to respond. Unfortunately you can't monitor this sort of site. This behaviour indicates a problem with your site or server that needs to be rectified. In this case you would be better opting out of emails entirely until the core issues have been remedied.
  
  

Pingalive tells me my site is down all the time, but i can browse to it fine.

• Some web servers are set up to refuse to handle http HEAD requests. There is no real reason for this and the server needs to be configured to handle this type of request. If you are on shared hosting you should raise a support ticket to have this fixed for you.
  

I want Google Analytics to ignore PingAlive's requests

• You can set the filters to ignore requests from 77.73.3.96 (PIngalive's IP address).