Documentation
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Overview ¶
Package sloghook provides a bun query hook that logs queries using slog and emits Prometheus histograms for query latency.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func WithCallsite ¶
WithCallsite returns a context carrying a bounded callsite label for db_query_duration_seconds. Callers must pass a value drawn from a small, known set (e.g. "uptimebar.bucket_availability", "results.list") — never anything derived from the raw SQL string or from request input, or the metric's cardinality stops being bounded.
Types ¶
type QueryHook ¶
type QueryHook struct {
// Verbose includes the full query in logs (may contain sensitive data).
// Affects logging only; metrics are always emitted.
Verbose bool
// Backend is the label value used on Prometheus metrics
// ("sqlite" or "postgres").
Backend string
// SlowThreshold logs a successful query at WARN when it takes at least
// this long. Zero (the default zero value) disables slow-query logging
// entirely — failures still log at WARN and everything else at DEBUG.
SlowThreshold time.Duration
// ThrottleInterval bounds how often the same normalized statement may
// log a slow-query WARN. Zero (the default zero value) falls back to
// defaultSlowQueryThrottleInterval; only tests override this.
ThrottleInterval time.Duration
// Now overrides the clock used for throttling (tests). Nil uses time.Now.
Now func() time.Time
// contains filtered or unexported fields
}
QueryHook is a bun query hook that logs SQL queries via slog and observes query latency via Prometheus.
func New ¶
New creates a new bun query hook. verbose controls whether full statements are written to slog; backend ("sqlite" or "postgres") is attached as a label to the emitted Prometheus metrics. slowThreshold logs a successful query at WARN once it takes at least that long; 0 disables slow-query logging.
func (*QueryHook) AfterQuery ¶
func (h *QueryHook) AfterQuery(ctx context.Context, event *bun.QueryEvent)
AfterQuery is called after executing a query. Emits the query-latency histogram, increments busy-retry counter on contention errors, and writes a slog line at DEBUG (success, below threshold), WARN (slow success), or WARN (failure) level.
func (*QueryHook) BeforeQuery ¶
BeforeQuery is called before executing a query.
Source Files