Cloud Computing: Redis on Google Cloud, When You Actually Need It

You’re building a little app. Maybe a login system, maybe a blog with comments, or perhaps something you’re not quite ready to show the world yet. Someone said, “Use Redis for caching, or die trying.” You don’t know what Redis does. Should I still use it?

What Is Redis?

Redis is in-memory key-value store. For example, a tiny brain next to your app that remembers things instantly like:

Who just logged in?
What their profile looks like
The result of a database query that’s slow
A temporary piece of data that only matters for 15 minutes

It’s like a scratch pad for your app. It doesn’t replace your database. But helps your app go zoom when it’s reading or writing little things over and over again.

Why Is It So Fast?

Because Redis lives in RAM, not on a hard disk. Think of it like your database is a filing cabinet. Redis is a sticky note on your monitor. One takes a while to open, read, and close.

When You Need Redis

If you’re just starting, here are real use cases where Redis is a huge win:

1. Session Storage (e.g., Logins)

You don’t want to store login sessions in your main database. Why? Because it’s overkill. Redis is perfect for temporarily storing data, such as user_id:logged_in_token.

2. Rate Limiting (Throttle Requests)

Got an API or login form? You can use Redis to keep track of requests per IP. If someone tries to log in 100 times in 1 minute? Redis remembers all that in memory — superfast.

3. Caching Database Queries

If you’re running a blog and your homepage hits the same SQL query every time, Redis can cache the result. No need to stress your database if the post didn’t change.

4. Real-Time Features (Chats, Leaderboards, etc.)

Redis has built-in data structures (sorted sets, lists, etc.) that are great for real-time features like live scores or chat messages.

When You Do Not Need Redis

Redis sounds sexy. But it’s not always necessary. You don’t need Redis if:

You have under 1,000 users.
Your app is for learning/testing.
You don’t have performance issues.
You don’t understand what problem Redis is solving.

A lot of beginner devs get sucked into adding Redis just because a tutorial told them to. Don’t architect for the scale you don’t have yet.

Redis on Google Cloud = Memorystore

You don’t install Redis on a VM. You use a managed service called Memorystore for Redis.

Why it’s great:

No need to install or patch anything.
Automatically scales
Integrates with GCP IAM and VPC
Handles failovers, backups, and monitoring for you

But it’s not free. Memorystore starts small but adds up fast if left running 24/7. You’re billed based on RAM and uptime.

Is It Secure?

When you use Memorystore, it lives inside your private VPC network. That means only your GCP services (like App Engine or Cloud Run) can talk to it — unless you mess with the firewall. If you’re rolling Redis yourself on a VM? Please don’t expose port 6379 to the open internet.

What It Costs — and What to Watch For

Memorystore pricing is RAM-based. As of writing:

~$0.026/hour for 1 GB (about $19/month if running 24/7)
No free tier
Still cheaper than debugging a slow app with a frustrated user base

To avoid surprises:

Use Standard Tier only when you need high availability.
Shut down idle Redis instances.
Monitor usage with Cloud Monitoring alerts.

You Don’t Need Redis to Look Smart

You need Redis when you’re solving a real problem — not when you’re trying to impress a recruiter with your tech stack. Add Redis when your app earns the right to be faster. And remember: it’s okay to build ugly, slow things first — that’s how you learn.