Redis Caching Patterns for High-Performance APIs

Posted on December 07, 2024 • #api #performance #caching #redis

Redis is more than just a cache—it's a powerful tool for building high-performance APIs. Here are some advanced Redis caching patterns that can supercharge your API performance.

Cache-Aside Pattern

public async Task<UserData> FetchUserData(string userId)
{
    // Try to get from cache
    var cached = await _redis.StringGetAsync($"user:{userId}");
    if (cached.HasValue)
        return JsonSerializer.Deserialize<UserData>(cached);

    // Cache miss - fetch from database
    var user = await _dbContext.Users.FindAsync(userId);

    // Store in cache with expiration
    await _redis.StringSetAsync(
        $"user:{userId}",
        JsonSerializer.Serialize(user),
        TimeSpan.FromHours(1)
    );

    return user;
}

Write-Through Caching

For frequently accessed data, consider write-through caching:

public async Task UpdateUserPreference(string userId, UserPreferences preferences)
{
    // Update database
    var user = await _dbContext.Users.FindAsync(userId);
    user.Preferences = preferences;
    await _dbContext.SaveChangesAsync();

    // Update cache atomically using transaction
    var transaction = _redis.CreateTransaction();
    transaction.StringSet(
        $"user:{userId}",
        JsonSerializer.Serialize(user),
        TimeSpan.FromHours(1)
    );
    await transaction.ExecuteAsync();
}

Pro tip: Use Redis TTLs (Time To Live) strategically. Not all data needs the same cache duration!