What is the Strikes Before Error setting?

Whenever a site encounters an error condition while taking a sample — for example, a search string is not found on a page, or a page takes longer than the given timeout value to load — then that sample could be logged as an error or strike and may cause an alert to be generated.

By default, our system uses a three-strike rule to determine whether to send an alert, which prevents extraneous alerts due to intermittent or localized problems. The three-strike rule works as follows:

  • The first time an error is detected, a strike is logged (denoted in yellow in the service's log files). No alert is sent.
  • After a 10-second delay, another attempt to collect the sample is made from a different monitoring location.
  • If the second sample is successful, that information is logged and no further action is taken.
  • If the second sample is unsuccessful and an error condition was detected, the sample is logged as a strike and a third attempt is made to take a sample.
  • If the third sample fails, the sample is logged as an error (denoted in red in the service's log files) and, depending on your alert settings, an alert is issued.

You can configure the number of strikes before error from 1 to 4, depending on your alerting needs. To change the Strikes Before Error setting:

  1. Click the service link in either the Dashboard or the Services tab.
  2. Open the Settings sub tab in the Services tab.
  3. Click Monitoring Settings.
  4. In the Monitoring Options section, select the desired value in the Strikes Before Error list.
  5. Click Save Settings.

If you have changed the number of strikes before error, then an alert will be sent on the final failed sample. For example, if the number of strikes before error is set to 1, then you will receive an alert every time an error condition is encountered; if the strikes before error is set to 4, then you will receive an alert on the fourth failed attempt to gather a sample. The final failed sample will be recorded in the service's log files as an error.

If you are monitoring simultaneously, instead of sequentially as described above, samples are taken all at once from different locations and an alert is issued if the appropriate number of the samples taken are unsuccessful, based on the number of strikes.

Baseline Agents versus Additional Agents

(Baseline and Additional Agents are configurable in the Services tab > Settings sub tab > Monitoring Agents list.)

  1. If a monitor strikes on a Baseline Agent, it will finish the X strike rule using available Baseline Agents. If no Baseline Agents are available, it will use the Additional Agents.
  2. If a monitor that uses Baseline Agents strikes on an Additional Agent, it will follow the Baseline/Non-Baseline alternation rule until it reaches the number of configured strikes.

See also