Notes for Week 8 of 2021

In my last pre-lockdown week, I was focused on moving forward some backend functionality. I went into a rabbit hole of different sync algorithms and making next.js work well with replicated databases.

Random

Vercel can deploy multiple projects on the same domain
Bitcoin source code is hosted by Microsoft in an organization that contains 29 people. Well, I guess it’s larger than FED Board, but still…
Django’s auto_now or auto_now_add will not create the default on the database level, at least not in MySQL (using the DEFAULT CURRENT TIMESTAMP); this has to be added manually
Making Jest and next.js work together can be tricky, here is a good summary guide
There is a draft for UUID v6 that essentially makes UUIDv1 usable as sortable database keys
TIL another date/time quirk: unix epoch time does not account for leap seconds and instead, two seconds have the same timestamp. Interestingly enough, the spec defines the day as exactly 86400 seconds, but leap seconds may not be only added, but also subtracted. Sounds like a good start for some Y2K-style mania, hope I’ll retire by then
The storage in browsers matured greatly. Instead of the original 5MB limit from few years back, you can now store up to 2 GBs of data (1GB in Chrome). There is now also an API for requesting data persistence
M1 notebooks have wear & tear on their internal on-chip M.2 NVMe SSDs. I suffer from it because of MacOS X bug: if connected monitor works in non-native resolution, WindowServer process leaks memory, happily eating double-digit GBs. Current workaround: shut computer down overnight. Has other advantages.
Swap usage on MacOS can be retrieved using sysctl vm.swapusage

Replicated Databases

In Prisma ORM, you can create multiple clients against different databases sharing the same schema by passing the connection string to a PrismaClient

import { PrismaClient } from '@prisma/client'
const client1 = new PrismaClient({
    datasources: {
        mydb: {
            url: 'postgres://user:password@host/dbname'
        }
    }
}

const client2 = new PrismaClient({
    datasources: {
        mydb: {
            url: 'postgres://user:password@differenthost/dbname'
        }
    }
}

Shopify wrote down considerations for using read-only replicas
When planning region build-out, I found useful Wondernetwork’s distance between cities, measured by ping times

Notes for Week 8 of 2021

Random

Replicated Databases

Recommended Readings From This Week