Help_Topics

Interpret error messages

Depending on your alert contact settings, alert messages can be sent out whenever your site encounters an error condition.

When you receive an email alert, you may receive one or both of the following types of email:

  • Alert Escalation Level 1, 2, or 3 emails are short and state just the service and the type of error:
  • Diagnostic emails are verbose and contain the details of the error:

These examples come from content error alert messages, but other alert and diagnostic emails are similar.

When you receive an error message, you can use any diagnostic information included with or in the email, such as HTML attachments or traceroutes, to help identify the issue. You can click on the link provided in the email to view more details, or you can log in and view the logs for that service, as described in Access_log_files. You will see something like this:

Clicking on one of the Detailed Trace links displays an error trace for that sample, to help you further diagnose any issues. Clicking the View Content link in the error trace allows you to view the page that was returned (if any), which can be helpful in determining what caused the error.

Content Errors

A content error occurs whenever an expected Verify Keyword or search string cannot be found on the page that was returned from the web server. A content error can also occur whenever an Error Keyword or error string is found on a page.

Viewing the log files and looking at the page that was returned when the error was detected often helps to identify why the content error was generated. Possible sources for content errors include (but are not limited to):

  • A search string or Verify Keyword was misspelled. See Change_the_URL_for_a_Website_Monitoring_service for more information about updating the Verify Keyword for Website Monitoring services, or Update_scripts to update search strings Application Monitoring scripts.
  • Site updates which change the content of a page, which may break search strings. Again, please view Change_the_URL_for_a_Website_Monitoring_service or Update_scripts to modify Verify Keywords or search strings.
  • Site maintenance, during which the user could be presented with an informational message about the downtime instead of the expected page. If you know there will be a period of planned downtime, consider setting up a maintenance window to prevent alerts from being sent out. More information can be found at Set_up_maintenance_windows.
  • Application issues, occurring either after a site update or intermittently, could potentially return an unexpected page.

Timeout Errors

A timeout error occurs whenever the time to download a page or item or to execute a transaction exceeds the allotted time as defined for that service in the Settings tab. See Configure_page_and_transaction_timeout_values for more information about configuring these values.

Some possible steps to take when diagnosing timeout errors include (but are not limited to):

  • Look at the traceroutes generated in the alert email or run a traceroute from the Diagnose tab for that service to identify any potential network issues along the way. Please see Run_a_traceroute_from_a_Webmetrics_agent_to_a_site for more information on running a traceroute.
  • Verify the server(s) are up and running and that they are manually connectible.
  • If certain pages are expected to take a bit of time to load due to the nature of their content or the application, you can increase the timeout value as described in Configure_page_and_transaction_timeout_values.

Connectivity Errors

Connectivity errors occur when sites return HTTP status codes which indicate errors, such as 500 errors.

Some possible steps to take when diagnosing timeout errors include (but are not limited to):

  • As with timeout errors, look at the traceroutes generated in the alert email or run a traceroute from the Diagnose tab for that service to identify any potential network issues along the way. Please see Run_a_traceroute_from_a_Webmetrics_agent_to_a_site for more information on running a traceroute.
  • Verify the server(s) are up and running and that they are manually connectible.
  • Check if anything was recently changed on your server(s), such as firewall settings.
  • Check the error logs on your server(s) for any messages at the timestamps when the errors were logged.

See also

Access_log_files
Change_the_URL_for_a_Website_Monitoring_service
Configure_page_and_transaction_timeout_values
Run_a_traceroute_from_a_Webmetrics_agent_to_a_site
Set_up_maintenance_windows
Update_scripts