How do you implement timeouts for non-HTTP operations like database queries and external calls?

Context-based timeouts apply to any blocking operation — database queries, cache lookups, file operations, and external gRPC calls. The pattern is identical: create a child context with a deadline and pass it to every blocking call.

// Database query with timeout
func getUserFromDB(ctx context.Context, db *sql.DB, id int) (*User, error) {
    // Add query-level timeout (in addition to any HTTP request timeout)
    ctx, cancel := context.WithTimeout(ctx, 2*time.Second)
    defer cancel()

    row := db.QueryRowContext(ctx,
        "SELECT id, name, email FROM users WHERE id = $1", id)

    var u User
    if err := row.Scan(&u.ID, &u.Name, &u.Email); err != nil {
        if errors.Is(err, context.DeadlineExceeded) {
            return nil, fmt.Errorf("DB query timed out after 2s: %w", err)
        }
        return nil, fmt.Errorf("getUserFromDB: %w", err)
    }
    return &u, nil
}

// Multiple operations with individual timeouts
func getUserProfile(ctx context.Context, userID int) (*Profile, error) {
    // DB: 2s timeout
    dbCtx, dbCancel := context.WithTimeout(ctx, 2*time.Second)
    defer dbCancel()
    user, err := getUserFromDB(dbCtx, db, userID)
    if err != nil { return nil, err }

    // Cache: 500ms timeout
    cacheCtx, cacheCancel := context.WithTimeout(ctx, 500*time.Millisecond)
    defer cacheCancel()
    prefs, _ := getPrefsFromCache(cacheCtx, userID) // non-fatal if cache misses

    // External API: 3s timeout
    apiCtx, apiCancel := context.WithTimeout(ctx, 3*time.Second)
    defer apiCancel()
    avatar, err := fetchAvatarFromCDN(apiCtx, user.AvatarURL)
    if err != nil {
        log.Printf("avatar fetch failed (non-fatal): %v", err)
    }

    return buildProfile(user, prefs, avatar), nil
}

Invest now in Acorns!!! 🚀
Join Acorns and get your $5 bonus!

Acorns is a micro-investing app that automatically invests your "spare change" from daily purchases into diversified, expert-built portfolios of ETFs. It is designed for beginners, allowing you to start investing with as little as $5. The service automates saving and investing. Disclosure: I may receive a referral bonus.

Invest now!!! Get Free equity stock (US, UK only)!

Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.

The Robinhood app makes it easy to trade stocks, crypto and more.

Webull! Receive free stock by signing up using the link: Webull signup.