Z3 · Scalability & Performance

Split app and database tiers

Gold

Moving the database onto its own server lets the app and data tiers be sized, scaled and replaced independently — the first step from one box to a system.

Use when: The app and database compete for the same CPU or memory · You need to scale or upgrade one tier without the other
Avoid when: Tiny workloads, where one box is cheaper and simpler
Trade-offs: A network hop per query vs independent scaling · Two machines to run and pay for
Requires: Server capacity & scaling up, Databases: the system of record

2 objectives · 6 misconceptions

choose Size app and database servers separately for a given mix of work.
predict Predict the latency added by putting the database across the network.

Not true: Splitting tiers adds no latency.
Not true: Separate tiers make the system redundant.
Not true: Services on one server don't slow each other down.
Not true: Splitting tiers saves money.
Not true: Many small network calls cost no more than one big one.
Not true: A network call inside a datacenter takes tens of milliseconds.

Learn

Split app and database tiersFree with an account~10 min

Practice

Launch dayFree with an accountmedium

Check

Station test-out80% to pass

Neighborhood

builds onServer capacity & scaling up Databases: the system of record

→Split app and database tiers→

unlocksAsync work with a queue Horizontal scaling with a stateless tier Read replicas

On linesScale Line