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

dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

dasgoll

1. Stop Ambari server
2. Log on to ambari server host shell
3. Run 'psql -U ambari-server ambari'
4. Enter password ****  (this password is stored in
/etc/ambari-server/conf/password.dat)
5. In psql:
update ambari.users set
user_password='538916f8943ec225d97a9a86a2c6ec0818c1cd400e09e03b660fdaaec4af29ddbb6f2b1033b81b00'
where user_name='admin'
6. Quit psql

filipefigcorreia

Kafka Topics

List existing topics

bin/kafka-topics.sh --zookeeper localhost:2181 --list

Purge a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

... wait a minute ...

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --delete-config retention.ms

rkuzsma

How to configure Bash Completion on Mac for Docker and Docker-Compose

Copied from the official Docker-for-mac documentation (thanks Brett for the updated doc pointer):

Install shell completion

Docker Desktop for Mac comes with scripts to enable completion for the docker, docker-machine, and docker-compose commands. The completion scripts may be found inside Docker.app, in the Contents/Resources/etc/ directory and can be installed both in Bash and Zsh.

Bash

Bash has built-in support for completion To activate completion for Docker commands, these files need to be copied or symlinked to your bash_completion.d/ directory. For example, if you installed bash via Homebrew:

roadrunner2

Introduction

This is about documenting getting Linux running on the late 2016 and mid 2017 MPB's; the focus is mostly on the MacBookPro13,3 and MacBookPro14,3 (15inch models), but I try to make it relevant and provide information for MacBookPro13,1, MacBookPro13,2, MacBookPro14,1, and MacBookPro14,2 (13inch models) too. I'm currently using Fedora 27, but most the things should be valid for other recent distros even if the details differ. The kernel version is 4.14.x (after latest update).

The state of linux on the MBP (with particular focus on MacBookPro13,2) is also being tracked on https://github.com/Dunedan/mbp-2016-linux . And for Ubuntu users there are a couple tutorials (here and here) focused on that distro and the MacBook.

Note: For those who have followed these instructions ealier, and in particular for those who have had problems with the custom DSDT, modifying the DSDT is not necessary anymore - se

yossorion

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

Tushar-N

import torch
import torch.nn as nn
import torch.nn.functional as F

import torchvision.models as tmodels
from functools import partial
import collections

# dummy data: 10 batches of images with batch size 16
dataset = [torch.rand(16,3,224,224).cuda() for _ in range(10)]

fevangelou

Looking to create a Software RAID 1 setup for your 2-disk server on Ubuntu Server 20.04?

Let's start with the basics: the official guide by Ubuntu (https://ubuntu.com/server/docs/install/storage) is outdated/wrong. And as of March 2021 it's possible that there's a bug as well with how the bios_grub partitions are created when using multiple disks.

Now on to the solution:

• Select "Custom storage layout" when you reach the storage configuration step of the installer.
• If the disks have existing partitions, click on each disk under AVAILABLE DEVICES and then select REFORMAT. This will (temporarily) wipe out the partitions.