VictoriaMetrics/app/vmalert/rule.go
Roman Khavronenko 877940a131
vmalert: add experimental feature of storing Rule's evaluation state (#3106)
vmalert: add experimental feature of storing Rule's evaluation state

The new feature keeps last 20 state changes of each Rule
in memory. The state are available for view on the Rule's
view page. The page can be opened by clicking on `Details`
link next to Rule's name on the `/groups` page.

States change suppose to help in investigating cases when Rule
doesn't generate alerts or records.

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2022-09-14 14:04:24 +02:00

104 lines
2.4 KiB
Go

package main
import (
"context"
"errors"
"sync"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
)
// Rule represents alerting or recording rule
// that has unique ID, can be Executed and
// updated with other Rule.
type Rule interface {
// ID returns unique ID that may be used for
// identifying this Rule among others.
ID() uint64
// Exec executes the rule with given context at the given timestamp and limit.
// returns an err if number of resulting time series exceeds the limit.
Exec(ctx context.Context, ts time.Time, limit int) ([]prompbmarshal.TimeSeries, error)
// ExecRange executes the rule on the given time range.
ExecRange(ctx context.Context, start, end time.Time) ([]prompbmarshal.TimeSeries, error)
// UpdateWith performs modification of current Rule
// with fields of the given Rule.
UpdateWith(Rule) error
// ToAPI converts Rule into APIRule
ToAPI() APIRule
// Close performs the shutdown procedures for rule
// such as metrics unregister
Close()
}
var errDuplicate = errors.New("result contains metrics with the same labelset after applying rule labels")
type ruleState struct {
sync.RWMutex
entries []ruleStateEntry
cur int
}
type ruleStateEntry struct {
// stores last moment of time rule.Exec was called
time time.Time
// stores the timesteamp with which rule.Exec was called
at time.Time
// stores the duration of the last rule.Exec call
duration time.Duration
// stores last error that happened in Exec func
// resets on every successful Exec
// may be used as Health ruleState
err error
// stores the number of samples returned during
// the last evaluation
samples int
}
const defaultStateEntriesLimit = 20
func newRuleState() *ruleState {
return &ruleState{
entries: make([]ruleStateEntry, defaultStateEntriesLimit),
}
}
func (s *ruleState) getLast() ruleStateEntry {
s.RLock()
defer s.RUnlock()
return s.entries[s.cur]
}
func (s *ruleState) getAll() []ruleStateEntry {
entries := make([]ruleStateEntry, 0)
s.RLock()
defer s.RUnlock()
cur := s.cur
for {
e := s.entries[cur]
if !e.time.IsZero() || !e.at.IsZero() {
entries = append(entries, e)
}
cur--
if cur < 0 {
cur = cap(s.entries) - 1
}
if cur == s.cur {
return entries
}
}
}
func (s *ruleState) add(e ruleStateEntry) {
s.Lock()
defer s.Unlock()
s.cur++
if s.cur > cap(s.entries)-1 {
s.cur = 0
}
s.entries[s.cur] = e
}