Web Server Monitoring provides webmasters and network administrators a peace of mind by ensuring they are always aware of the status of their web sites and web applications. Since its birth in 1998 Dotcom-Monitor has been positioned as a leading webserver monitoring company ready to offer world-class monitoring and notification services. Years of successful work enriched us with inestimable experience and taught us to detect and analyze quickly all the real and possible bottlenecks of our clients' systems. Web Server Performance depends on a number of factors: web server configuration, web server CPU load, the number of services running on the server, the number of users accessing the server at a given moment. Any one of these factors may cause poor web server performance, which will make people wait too long and even leave your website. When a server performs slowly it nevertheless does work, so no records will be created in error logs. Thus you will never know people experience trouble when accessing your site. When monitoring a web server for potential problems, Dotcom-monitor.com checks a number of parameters. First of all, we monitor for a proper HTTP return code. By HTTP specifications RFC 2616, any web server returns several HTTP codes. Analysis of the HTTP codes is the fastest way to determine the current status of the monitored web server. If Dotcom-Monitor.com detects the status code to be outside the 200-300 range it will consider the event to be a failure and will initiate a web server notification process.

Status Code  Meaning 200 OK 201 Created 202 Accepted 204 No Content 301 Moved Permanently 302 Moved Temporarily 304 Not Modified 400 Bad Request 401 Unauthorized 403 Forbidden 404 Not Found 500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable

HTTP codes only are available when our web server monitoring software is able to connect to website and monitored web server responded with proper answer. There are number of instances where our monitoring service is unable to connect to web server within preset monitoring timeout. This could be because of several reasons. Most common issues would be

Code Error Name Error Description
12002	ERROR_INTERNET_TIMEOUT	The request has timed out.
12005	ERROR_INTERNET_INVALID_URL	The URL is invalid.
12007	ERROR_INTERNET_NAME_NOT_RESOLVED	The server name could not be resolved.
12013	ERROR_INTERNET_INCORRECT_USER_NAME	The request to connect and log on to an FTP server could not be completed because the supplied user name is incorrect.
12014	ERROR_INTERNET_INCORRECT_PASSWORD	The request to connect and log on to an FTP server could not be completed because the supplied password is incorrect.
12015	ERROR_INTERNET_LOGIN_FAILURE	The request to connect to and log on to an FTP server failed.
12029	ERROR_INTERNET_CANNOT_CONNECT	The attempt to connect to the server failed.
12030	ERROR_INTERNET_CONNECTION_ABORTED	The connection with the server has been terminated.
12031	ERROR_INTERNET_CONNECTION_RESET	The connection with the server has been reset.
12037	ERROR_INTERNET_SEC_CERT_DATE_INVALID	SSL certificate date that was received from the server is bad. The certificate is expired.
12038	ERROR_INTERNET_SEC_CERT_CN_INVALID	SSL certificate common name (host name field) is incorrect. For example, if you entered www.server.com and the common name on the certificate says www.different.com.
12039	ERROR_INTERNET_HTTP_TO_HTTPS_ON_REDIR	The application is moving from a non-SSL to an SSL connection because of a redirect.
12040	ERROR_INTERNET_HTTPS_TO_HTTP_ON_REDIR	The application is moving from an SSL to a non-SSL connection because of a redirect.
12041	ERROR_INTERNET_MIXED_SECURITY	Indicates that the content is not entirely secure. Some of the content being viewed may have come from unsecured servers.
12150	ERROR_HTTP_HEADER_NOT_FOUND	The requested header could not be located.
12151	ERROR_HTTP_DOWNLEVEL_SERVER	The server did not return any headers.
12152	ERROR_HTTP_INVALID_SERVER_RESPONSE	The server response could not be parsed.
12153	ERROR_HTTP_INVALID_HEADER	The supplied header is invalid.

If we detect any of the above error codes during web server monitoring, we assume that there is a problem with the web server and start alert escalation process as preset by the user. The "Uptime Alert" may be sent to the user as soon as the problem is solved.

If a problem is detected, web server monitoring process will perform several actions to help the client to troubleshoot the issue:

	It will take an immediate trace route from the agent location where the problem was detected.  click here for a screenshot
	If we were able to connect to the web server, but received an invalid HTTP code or invalid content, we will take an immediate snapshot of the page that was returned during the monitoring process.  click here for an example

Both the steps taken during web server monitoring should help the user pinpoint the root cause of the problem.

All the collected data may be presented as a set of detailed web server monitoring reports and web server performance charts. We send daily, weekly, and monthly email reports, which bring the monitoring results in a systematized and well-organized form.