jboner

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

andreyvit

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

rgreenjr

-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

night-before-opsmas.txt

'Twas the night before Christmas, when all through the racks
Not a server was alerting, not even Compaqs.
The backups were written to tapes with care
In hopes that later the data would be there.

The machines were nestled all snug in their sleds
Whilst visions of vengeance danced in their heads;
And oncall in his three-wolf and I in my rack.
Had just settled down for some syn and some ack.

leonardinius

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

derhansen

Redis::connection()->del('queues:myqueue');

eladnava

#!/bin/sh

# Make sure to:
# 1) Name this file `backup.sh` and place it in /home/ubuntu
# 2) Run sudo apt-get install awscli to install the AWSCLI
# 3) Run aws configure (enter s3-authorized IAM user and specify region)
# 4) Fill in DB host + name
# 5) Create S3 bucket for the backups and fill it in below (set a lifecycle rule to expire files older than X days in the bucket)
# 6) Run chmod +x backup.sh
# 7) Test it out via ./backup.sh

johnduarte

FYI, for those of us running Debian based systems rather than RedHat, the BlueJeans RPM can be successfully installed via alien

Steps to install BlueJeans on Debian

• Download BlueJeans RPM
• Install alien package sudo apt-get install alien
• Convert BlueJeans RPM to a DEB package sudo alien --to-deb --scripts bluejeans-*.rpm
• Install resulting DEB sudo dpkg -i bluejeans_*.deb
• Run BlueJeans with /opt/bluejeans/bluejeans-bin

You may get an error loading the expected udev library

zmts

Про токены, JSON Web Tokens (JWT), аутентификацию и авторизацию. Token-Based Authentication

Last major update: 25.08.2020

• Что такое авторизация/аутентификация
• Где хранить токены
• Как ставить куки ?
• Процесс логина
• Процесс рефреш токенов
• Кража токенов/Механизм контроля токенов

cpursley

PostgreSQL is Enough

• Simplify: move code into database functions
• Just Use Postgres for Everything
• PostgreSQL is the worlds’ best database
• Postgres is eating the database world
• Hacker News discussion

Background and Cron Jobs