Advanced Mode Trigger

Sometimes a simple trigger (Simple Threshold Trigger) doesn’t provide enough flexibility for your task.

For example, you may want to receive a notification when 5% of user requests take up more than a second to process, but only if there are more than 100 requests per minute. Usually, you will have two separate metrics for this:

  1. Nginx.requests.process_time.p95 - 95th percentile of request processing time in milliseconds
  2. Nginx.requests.count - request count per minute

Maybe you can construct a monstrous Graphite expression to reflect this combination, but Moira’s Advanced Mode is better:

advanced trigger

You can use any govaluate expression with predefined constants here:

  • t1, t2, … are values from your targets
  • OK, WARN, ERROR, NODATA are states that must be the result of evaluation
  • PREV_STATE is equal to previously set state, and allows you to prevent frequent state changes

Note

Only T1 target can resolve into multiple metrics in Advanced Mode. T2, T3, … must resolve to single metrics. Moira will calculate expression separately for every metric in T1.

Any incorrect expressions or bad syntax will result in EXCEPTION trigger state.