Igor Grishin bigspawn

-- Firstly, remove PRIMARY KEY attribute of former PRIMARY KEY
ALTER TABLE <table_name> DROP CONSTRAINT <table_name>_pkey;

-- Then change column name of  your PRIMARY KEY and PRIMARY KEY candidates properly.
ALTER TABLE <table_name> RENAME COLUMN <primary_key_candidate> TO id;

How do you POST a JSON file with curl??

You can post a json file with curl like so:

curl -X POST -H "Content-Type: application/json" -d @FILENAME DESTINATION

so for example:

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

CPU: percentage of limit

A lot of people land when trying to find out how to calculate CPU usage metric correctly in prometheus, myself included! So I'll post what I eventually ended up using as I think it's still a little difficult trying to tie together all the snippets of info here and elsewhere.

This is specific to k8s and containers that have CPU limits set.

To show CPU usage as a percentage of the limit given to the container, this is the Prometheus query we used to create nice graphs in Grafana:

sum(rate(container_cpu_usage_seconds_total{name!~".*prometheus.*", image!="", container_name!="POD"}[5m])) by (pod_name, container_name) /

Используем protobuff версии 3 https://developers.google.com/protocol-buffers/docs/proto3

Придерживаемся стиля https://developers.google.com/protocol-buffers/docs/style

Если вы удалили поля message определенные ранее, то для сохранения совместимости, их номера должны быть помечены как reserved, чтобы их нельзя было использовать повторно после.

Поддержка версионирования API - см. https://google.aip.dev/215

Переиспользуем готовые определения часто используемых типов (время, деньги, дата и др.) см. https://google.aip.dev/213

	#!/bin/bash

	# store the current dir
	CUR_DIR=$(pwd)

	# Let the person running the script know what's going on.
	echo "\n\033[1mPulling in latest changes for all repositories...\033[0m\n"

	# Find all git repositories and update it to the master latest revision
	for i in $(find . -name ".git" \| cut -c 3-); do

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	background #e8e9ec
	foreground #33374c

	selection_background #d2d4dd
	selection_foreground #33374c

	cursor #33374c
	cursor_text_color #e8e9ec

	# white