Efremenko Arhip
0c1f5f06d4
- delete api/requests.http and ARCHITECTURE.md (coordinator content) - rewrite README.md and .env.example for the userservice - drop dead RunPeriodic (reaper machinery userservice has no use for) - fix .gitignore/.dockerignore/.golangci.yml module + artifact names - degeneralize stale copied comments that said "coordinator"
66 lines
2.0 KiB
Go
66 lines
2.0 KiB
Go
// DB: the PostgreSQL connection pool.
|
|
package infra
|
|
|
|
import (
|
|
"context"
|
|
"log/slog"
|
|
"time"
|
|
|
|
"github.com/cenkalti/backoff/v4"
|
|
"github.com/jackc/pgx/v5/pgxpool"
|
|
)
|
|
|
|
// NewPool builds the single shared pool. The caller owns its lifetime and must
|
|
// Close() it on shutdown.
|
|
func NewPool(ctx context.Context, cfg Config, log *slog.Logger) (*pgxpool.Pool, error) {
|
|
poolCfg, err := pgxpool.ParseConfig(cfg.DatabaseURL)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
poolCfg.MaxConns = cfg.DBMaxConns
|
|
|
|
pool, err := pgxpool.NewWithConfig(ctx, poolCfg)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// pgxpool.New is lazy, so a ping is needed to actually reach the server.
|
|
// It is retried because at startup — especially under docker-compose, where
|
|
// this service can boot before Postgres is accepting connections — a
|
|
// service should wait for its database rather than crash-loop.
|
|
if err := pingWithRetry(ctx, pool, cfg.DBConnectTimeout, log); err != nil {
|
|
pool.Close()
|
|
return nil, err
|
|
}
|
|
return pool, nil
|
|
}
|
|
|
|
// pingWithRetry waits for the database to accept connections, backing off
|
|
// between attempts until the budget elapses or ctx is cancelled.
|
|
//
|
|
// Unlike the transaction retry in storage/postgres, this retries *any* ping
|
|
// error: at startup a "connection refused" is the expected, retryable state,
|
|
// not an anomaly.
|
|
func pingWithRetry(ctx context.Context, pool *pgxpool.Pool, budget time.Duration, log *slog.Logger) error {
|
|
b := backoff.NewExponentialBackOff()
|
|
b.InitialInterval = 200 * time.Millisecond
|
|
b.MaxInterval = 3 * time.Second
|
|
b.MaxElapsedTime = budget
|
|
|
|
attempt := 0
|
|
return backoff.RetryNotify(
|
|
func() error {
|
|
// A bounded per-attempt timeout so one hung dial cannot eat the
|
|
// whole budget in a single try.
|
|
pingCtx, cancel := context.WithTimeout(ctx, 3*time.Second)
|
|
defer cancel()
|
|
return pool.Ping(pingCtx)
|
|
},
|
|
backoff.WithContext(b, ctx),
|
|
func(err error, next time.Duration) {
|
|
attempt++
|
|
log.Warn("database not ready, retrying",
|
|
"attempt", attempt, "retry_in", next.String(), "err", err)
|
|
},
|
|
)
|
|
}
|