// Save metric and index into db.
func (d *Detector) save(m *models.Metric, idx *models.Index) error {
// Save index.
if err := d.db.Index.Put(idx); err != nil {
return err
}
// Save metric.
m.LinkTo(idx) // Important
if err := d.db.Metric.Put(m); err != nil {
return err
}
return nil
}
// analyze given metric with 3sigma, returns the new index.
// Steps:
// 1. Get index.
// 2. Get history values.
// 3. Do 3sigma calculation.
// 4. Move the index next.
func (d *Detector) analyze(idx *models.Index, m *models.Metric, rules []*models.Rule) *models.Index {
fz := idx != nil && d.shouldFill0(m, rules)
if idx != nil {
m.LinkTo(idx)
}
vals, err := d.values(m, fz)
if err != nil {
return nil
}
d.div3Sigma(m, vals)
return d.nextIdx(idx, m, d.pickTrendingFactor(rules))
}