Troubleshooting Monitoring Errors

First, check if there are responses with the same error type and code from other regions.

If the errored responses come only from locations of a particular region, try to switch between locations within the region and monitor the responses state. Generally, if the error persists at the same locations or region, it could be caused by a connectivity issue in the middle between the monitoring location and the monitored web resource.

If the sessions failed at more than one region, check the configuration of the host’s web server (server timeout, firewall rules, etc.) and the device settings (invalid keyword or image validation settings, etc.).

To troubleshoot routing issues in the affected location, Dotcom-Monitor provides a free traceroute tool. Although, to find out a server which returns an errored response you can use the Network Trace or DNS Trace reports attached to the error messages (depending on the error type).

If the response body is available, to visualize the response, click the Body link. In the preview window, click Preview and open the downloaded file in the browser window.

In the case of BrowserView or UserView tasks, you can validate an element which generates an error manually:

1. On the Log tab, apply the Failures Only filter to the log.

2. Expand a failed session row in the log to access the session details with element list.

3. Find the element which generates the error (an error type is provided in the Error Type(s) column).

4. Copy the link to element to the browser window and execute it manually:

• If there is no issue with element execution, see the Troubleshoot by error section of this article.
• If you receive the same error that occurred while device execution, check issues on the host side.

To troubleshoot a Validation Error, see the error message in the related info tip or in the session details and validate content manually. For example, in the case of keyword validation failure, check the keyword presence on the target resource in your browser.

If content validation is successful from your computer and your server doesn’t serve different content for different regions, contact technical support.

To troubleshoot timeout errors, check the script duration time.

In the case of DNSBL Task, Validation Error could indicate that the target host IP address is in the DNSBL database.

In the case of the Email Round Trip Task, make sure the address specified in the Email From field is not in the spam list.

The error is typical for UserView and Custom Script tasks as well as for HTTP(S) tasks with a custom script added. The error indicates the issues in the script (some script variables are invalid or cannot be found). Check if all the variables used in the script are specified in the task or present on the target resource.

Check the monitoring task for errors in its configuration. Pay attention to custom scripts if any. 

See also: Runtime Error (130): The request was aborted

Certificate Error type indicates SSL certificate issues which occur while connecting to web resources via HTTPS.

Check the error message in the session details to find the reason for the issue with the SSL certificate.

If such errors are expected (e.g. in the case of self-signed certificate), disable certificate verification:

• To ignore certificate warnings for UserView tasks, add Certificate Handler to the monitoring script.
• To manage certificate monitoring for HTTPS Task, configure the SSL/Certificate Check option.

The error type indicates that Dotcom-Monitor can not establish a secure connection with a remote web server due to different encryption algorithms or encryption modes which are set for encryption on the remote server side.

To solve this issue, contact technical support.

TCP Error indicates a data transmission failure at the transport layer. The TCP errors are mostly of a temporary nature and occur due to routing or other network issues between Dotcom-Monitor monitoring locations and the client’s host. Due to the nature of such issues, it is difficult to detect a reason for network errors on the spot.

Generally, it is recommended to enable Alert Silence for the device with TCP errors for a time until the errors will be fixed.

You can also check the locations the error is generated from. If the error is generated from several monitoring locations, suspend monitoring from the locations with errored responses in the device settings, and resume it later. If the error persists at the same locations, it could be due to the backbone outage occurred within the region. To visualize the traceroute and see backbones where a loss in traffic performance occurred (if any), use a free Dotcom-Monitor traceroute tool.

Additionally, check the web server configuration and firewall rules on the host side.

DNS or the Domain Name System converts domain names to IP addresses so browsers can load web resources. DNS resolution is the process of the translation from website name entered into the URL area of a web browser to the corresponding IP address.

The most common causes of DNS issues are the DNS Server issues by itself and all types of network problems between the Dotcom-Monitor monitoring locations and the DNS Servers (Internet Provider DNS Problem, TCP connection issues, firewall rules, router problems, etc.).

For more issue details such as the DNS server which returns an errored response, use the traceroute tool or DNS tree available by clicking the related DNSTrace link in the log.

To troubleshoot a DNS issue, first, make sure there were no changes with the domain names on your side (connect your IT department). Then check server timeout settings and firewall rules.

Generally, it is recommended to enable Alert Silence for the device with a DNS error for a time until the error will be fixed.

If the error is generated at several monitoring locations, suspend monitoring from the locations in the device settings and resume it later. If the error persists at the same locations, consider changing the DNS mode in the device settings.

The error indicates connectivity problems. To investigate the issue, contact technical support.

The error indicates HTTP(S) issues on the target web resource and the web server. See all HTTP status codes to troubleshoot the issue.

To see on which server the traffic performance loss occurred if any, check the response Trace report.

In general, check if there were any changes in the web resource structure, web site updates, changes in the redirect settings, etc.

For example, in the case of a redirect error update the target URL in the device settings or edit the monitoring script.

The error indicates FTP server connection problems such as FTP server login issues, insufficient access permissions, etc.

Try to reproduce the failed task manually using an FTP client, for example, connect to the target FTP server using credentials specified in the task. If login is successful, check the access permissions for monitored folders or files.

SMTP error reflects connectivity problems that occurred while sending mail via SMTP.

POP3 and IMAP errors indicate issues with mail receiving.

ActiveSync error is specific for ActiveSync task and indicates issues with Microsoft Exchange Server.

To troubleshoot the errors that occurred while Mail Servers monitoring, connect to the target mail server via the default mail client using the same settings which were specified in the task. In the case of an error, you will receive an error message with the problem details in your mail client.

The errors occur in PING and TRACEROUTE tasks. Typically, such type of errors present in the Trace visualization for errored responses. Check the error message and attached Trace report in the log to find more diagnostic details.

The errors indicate issues with access to DNSBL servers. The possible reasons are network problems and errors that occurred at the DNSBL server.

Generally, it is recommended to enable Alert Silence for the device until the error will be fixed.

The main reasons for the Media Streaming Task errors are the host’s server connectivity issues or problems with media replay on Dotcom-Monitor side.

First, try to make sure the target media source is active and can be accessed via a browser or via a media player. If there is no issue with the media source, contact technical support.

Otherwise, contact your Internet provider to fix connectivity issues.

You can also check the availability of the web page where the errored media source is consumed by users. The simplest way to do this is to create HTTP Task for a media source web page monitoring.

To troubleshoot the task, find more details in the error message.

The most frequently occurred issues with SIP monitoring are:

• Invalid SIP task settings. Check host parameters and SIP credentials provided in the task.
• Host’s IP address or port provided in the task are blocking with IP PBX security software. Check the host’s firewall settings and make sure the IP and port are opened.
• A source domain name set on the PBX (client domain name) is not registered on the DNS server. Set DNS Resolve mode to External DNS Server in the task settings to perform internal DNS resolution by Dotcom-Monitor.