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This.isDevOps(powah_code=36)

Thuan Duong thuandt

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This.isDevOps(powah_code=36)
  • Ho Chi Minh, Vietnam
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View quick-tips-optimizing-jvm.md

Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

View types.markdown

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

@ffittschen
ffittschen / gitconfig.md
Last active Oct 15, 2021
Use IntelliJ or WebStorm as git mergetool with SourceTree
View gitconfig.md

Use IntelliJ or WebStorm as git mergetool

Configure Sourcetree

The merge tool that ships with JetBrain's IntelliJ IDEA or WebStorm is really awesome and way better than FileMerge. It is quite simple to configure SourceTree to use it as the default mergetool:

  1. Open the SourceTree preferences and select the Diff tab

  2. Choose Custom both as Visual Diff Tool and as Merge Tool

  3. Paste the following commands into the textfields:

    • Diff Command: /Applications/IntelliJ\ IDEA.app/Contents/MacOS/idea diff
@alirobe
alirobe / reclaimWindows10.ps1
Last active Oct 16, 2021
This Windows 10 Setup Script turns off a bunch of unnecessary Windows 10 telemetery, bloatware, & privacy things. Not guaranteed to catch everything. Review and tweak before running. Reboot after running. Scripts for reversing are included and commented. Fork of https://github.com/Disassembler0/Win10-Initial-Setup-Script (different defaults). N.…
View reclaimWindows10.ps1
##########
# Tweaked Win10 Initial Setup Script
# Primary Author: Disassembler <disassembler@dasm.cz>
# Modified by: alirobe <alirobe@alirobe.com> based on my personal preferences.
# Version: 2.20.2, 2018-09-14
# Primary Author Source: https://github.com/Disassembler0/Win10-Initial-Setup-Script
# Tweaked Source: https://gist.github.com/alirobe/7f3b34ad89a159e6daa1/
# Tweak difference:
#
# @alirobe's version is a subset focused on safely disabling telemetry, some 'smart' features and 3rd party bloat ...
@acolyer
acolyer / service-checklist.md
Last active Oct 13, 2021
Internet Scale Services Checklist
View service-checklist.md

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

Basic tenets

  • Does the design expect failures to happen regularly and handle them gracefully?
  • Have we kept things as simple as possible?
View useful_pandas_snippets.md

Useful Pandas Snippets

A personal diary of DataFrame munging over the years.

Data Types and Conversion

Convert Series datatype to numeric (will error if column has non-numeric values)
(h/t @makmanalp)

View latency.markdown

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
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 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs
Read 1 MB sequentially from memory ..... 250,000 ns  = 250 µs           4X memory
@denji
denji / nginx-tuning.md
Last active Oct 15, 2021
NGINX tuning for best performance
View nginx-tuning.md

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

@XVilka
XVilka / TrueColour.md
Last active Oct 18, 2021
True Colour (16 million colours) support in various terminal applications and terminals
View TrueColour.md

Most updated version is always available at termstandard/colors repository.

Terminal Colors

There exists common confusion about terminal colors. This is what we have right now:

  • Plain ASCII
  • ANSI escape codes: 16 color codes with bold/italic and background
  • 256 color palette: 216 colors + 16 ANSI + 24 gray (colors are 24-bit)
  • 24-bit truecolor: "888" colors (aka 16 million)