Status of Internal websites by using PING - asp.net

Question

Afternoon All,
Just after a bit of advice on the best method to use for the following.
I am new ish to .net and have an Asp.net web page in development that i simply lists some internal web sites by a ping command and outlines their status (on-line / offline). This is current;y activated by the click of a button.
I need to set up this developemt web page so that it automatically runs at a specific time on a morning say 7am for arguments sake and to then notify a user group by email the status of these items.
I have used Microsoft Visual studio (VB) 2010 before and can create simple web works that connect/ extract/ update data to and from SQL 2008. I have also had some experience in creating scheduled jobs in SQL but not much.
I thought i could maybe create a scheduled job in SQL 2008, find a way to populate the data into the database, use this data in my website and display it a gridview or something. And either have the SQL job or the website email a group of users the status of these internal web sites.
Does anyone know if i would beable to complete the above just in .net? Am i able to write a script of some sort or schedule the web page to run at a specified time?
Im not 100% sure on the best method to tackle this job and i have limited experience. Can anyone suggest any best method ideas on how to complete the above.
Regards
Bet.

Answer 1

Although fairly trivial to implement, I don't believe a ping command is useful in the context of what you are trying to achieve.
As Fredrik pointed out, a ping only says that the server is available. It makes no statement as to whether an individual website is functional on that server.
If I was doing this I would create a service that runs every so often. The service would issue a get request to the web sites, do a little bit of parsing on the content to make sure what was returned was expected, and update a record in a database stating the time of the connection and the status (up/down).
For example:
public String CheckSite(String postLocation) {
HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(postLocation);
// Setting the useragent seems resolves certain issues that *may* crop up depending on the server
httpRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
httpRequest.KeepAlive = false;
httpRequest.Method = "GET";
using ( HttpWebResponse httpResponse = (HttpWebResponse)httpRequest.GetResponse() ) {
using ( StreamReader reader = new StreamReader(httpResponse.GetResponseStream()) ) {
result = reader.ReadToEnd();
} // using reader
} // using httpResponse
return result;
}
This simple call will load a page from a server. From there you can parse to see if you have words like "error" or what have you. Provided it looks good then you report back that the site is up.
I know the above is C#, but you should be able to easily convert that to VB if necessary. You should also place a try .. catch around the call. If it errors out then you know the server is completely offline. If the page returns, but contains "error" or something then you know the server is up but the app is down.

Answer 2

pesronally . . . I think the most elegant solution would be: (untested)
public String CheckSite(String postLocation) {
HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(postLocation);
// Setting the useragent seems resolves certain issues that *may* crop up depending on the server
httpRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
httpRequest.KeepAlive = false;
httpRequest.Method = "GET";
using ( HttpWebResponse httpResponse = (HttpWebResponse)httpRequest.GetResponse() ) {
if(httpResponse.StatusCode != {check for valid status codes here})
{
//Do something based upon an invalid response.
}
} // using httpResponse
return result;
}