Web server monitoring provides webmasters and network administrators a peace of mind by ensuring they are always aware of the status of their websites 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 alert 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 without server performance monitoring you will never know people experience trouble when accessing your site.
All web servers provide a return code - in most cases, several codes. Dotcom-Monitor checks web server for a number of parameters looking for proper HTTP return codes using specifications from RFC 2616. Analysis of the HTTP codes is the fastest way to determine the current status of the monitored web server.
Whenever Dotcom-Monitor 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 alert process.
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.|
|12038||ERROR_INTERNET_SEC_CERT_CN_INVALID||The certificate is expired. SSL certificate common name (host name field) is incorrect.|
|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 server uptime problem is detected, web server performance monitoring process will perform several actions to help the client to troubleshoot the issue:
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.