caniszczyk

#!/bin/sh

#
# For each ref, validate the commit.
#
# - It disallows deleting branches without a /.
# - It disallows non fast-forward on branches without a /.
# - It disallows deleting tags without a /.
# - It disallows unannotated tags to be pushed.

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

carlosspohr

For your Ruby, you'll must install this gems:

sudo gem install passenger

sudo passenger-install-apache2-module

At this moment, you'll asked to install some Apache2's deps (three deps):

sudo apt-get install apache2-prefork-dev

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm