.tip

Jun 10, 2026 · one of the small things

The caller's timeout must be shorter than the callee's

Say your service times out at 30 seconds and the API it calls does too. The upstream gives up first, you spend the last second doing nothing useful, and then you return an error to a client that has already stopped waiting.

client → gateway 10s → service 8s → database 5s

Make each hop shorter than the one before it. That way a timeout fails at the layer that can still do something about it.

httpreliability

~/tips/today — 2026-10-19

~cat tips/today

Never build an index on a live table without CONCURRENTLY

postgresqlmigrations

A plain CREATE INDEX takes a lock that blocks every write to the table for the whole build. On a big table that means minutes of outage that look like a hung app.

CREATE INDEX CONCURRENTLY orders_customer_idx ON orders (customer_id);

It's slower and can't run inside a transaction, so you'll have to tell your migration tool. If it fails halfway, it leaves an invalid index behind, so check pg_index.indisvalid and drop it before you retry.

↵ open y yesterday l ls /tips

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