Documentation
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Overview ¶
Package levelalert evaluates conditions that have a warning and a critical level and routes them to notification channels (#2148, #2149).
An evaluator hands Apply every condition it found at warning or critical on this pass. Each is sent to the configured channels under a key carrying its level, every pass, so the channel's repeat window decides how often a standing condition is repeated and a move from warning to critical is a new key the warning's window cannot hold back. A condition that was alerting on the previous pass and is not in this one has cleared: a resolved notification is sent once, under its own key, and its record is removed. The records live in alert_conditions so a restart, or the next pass running on another replica, still knows what was alerting.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
Types ¶
type Engine ¶
type Engine struct {
// contains filtered or unexported fields
}
Engine applies a family's findings.
func New ¶
New returns an engine, or nil when store is nil. A nil sender records conditions and sends nothing.
func (*Engine) Apply ¶
func (e *Engine) Apply(ctx context.Context, family string, channels []string, findings []Finding, unknown ...string) (Result, error)
Apply sends each finding at its level to channels, sends a resolved notification for each condition of family that was alerting and is not among findings, and records the result.
unknown names key prefixes whose conditions this pass could not judge (a store that could not be read): what was recorded under them is left as it stands, neither resolved nor sent again, until a pass can judge them.
A send's key carries the condition, its level and when that level began, so the channel's repeat window holds back repeats of one episode while a condition that clears and returns, or changes level, is posted at once.
type Finding ¶
type Finding struct {
// Key names the condition and what it is about, unique within its
// family: webhook:spool_age:replica-a. It never carries the level.
Key string
Level Level
// Title is the notification's one line: what, where, how bad.
Title string
// Body is markdown: the value, the threshold, and what to look at.
Body string
// Link is the admin page the condition is seen on.
Link string
}
Finding is one condition at warning or critical.
type Level ¶
type Level string
Level is how bad a condition is.
The levels a condition is reported at.
type PostgresStore ¶
type PostgresStore struct {
// contains filtered or unexported fields
}
PostgresStore is the alert_conditions table.
func NewPostgresStore ¶
func NewPostgresStore(db *sql.DB) *PostgresStore
NewPostgresStore returns the store over db.
func (*PostgresStore) Delete ¶
func (s *PostgresStore) Delete(ctx context.Context, key string) error
Delete removes a condition that cleared.
type Sender ¶
type Sender interface {
Send(ctx context.Context, names []string, key string, p notification.Payload) int
}
Sender queues an alert for notification channels. notifyalert.Sender satisfies it.
type Store ¶
type Store interface {
List(ctx context.Context, family string) ([]Record, error)
Upsert(ctx context.Context, family string, f Finding, now time.Time) error
Delete(ctx context.Context, key string) error
}
Store keeps the conditions each family found on its last pass.
type Thresholds ¶
type Thresholds struct {
Warning float64 `json:"warning"`
Critical float64 `json:"critical"`
Below bool `json:"-"`
}
Thresholds are the two values a reading is judged against. A zero threshold is off. Below marks a reading that is worse the lower it is (free space, days left); otherwise higher is worse.
func (Thresholds) Of ¶
func (t Thresholds) Of(v float64) Level
Of returns the level v is at, or "" when it is under both thresholds.
Source Files