Monitoring tasks are assigned to Private Agents according to the monitoring device settings. Private Agent can reject to run a monitoring session or fail to return monitoring results to the server due to various reasons.
Possible reasons for failures in monitoring sessions include the following:
- Session limitations on the Private Agent.
- Server resources limitations.
- Connectivity issues.
- Other issues. Contact technical support for more details.
Put another way, the ratio represents the number of monitoring sessions that were rejected from monitoring by the agent or never returned monitoring results. Failed Ratio is the proportion of Private Agent failed sessions and all sessions that had to be executed on the Private Agent. Failed Ratio is provided for each Private Agent on the Private Agents manager page (Configure > Private Agents).
Failed Ratio values vary between monitoring sessions. Generally, the ratio under 10% is considered acceptable. However, the ratio value over 10% points to issues on the corresponding Private Agent and should be examined.
There are five Private Agent services available to execute the monitoring devices on the Private Agent. Each service is capable of executing a single monitoring session at one time, thus five sessions can be executed in parallel.
When all the services are in use, and one more session is scheduled to be started, the session limit will be reached and the Private Agent will fail to execute the session. In this case, the failure will be reflected by the Failed Ratio value.
To prevent Private Agent failures, consider the monitoring frequency and device execution duration, as well as the number of devices that must be executed on the Private Agent. To calculate the number of Private Agents for your monitoring requirements, see How many Private Agents will be required.
Server Resources Limitation
During monitoring execution, the server resources limit (CPU, memory, etc.) can be hit on the Private Agent server. To avoid overload situations, consider CPU requirements during Private Agent installation.
If network connection issues occur during the monitoring session, the Private Agent results will not received by Dotcom-Monitor. Such sessions are considered failed and are presented in the Failed Ratio value.