swalkinshaw

Moved to Shopify/graphql-design-tutorial

djspiewak

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

aparrish

aparrish

davisford

Add the `replication` section to the mongod.conf file:

```
$cat /usr/local/etc/mongod.conf
systemLog:
  destination: file
  path: /usr/local/var/log/mongodb/mongo.log
  logAppend: true
storage:
  engine: mmapv1

rondy

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

---

Effective Engineer - Notes

• By Edmond Lau
• Highly Recommended 👍
• http://www.theeffectiveengineer.com/

What's an Effective Engineer?

hernamesbarbara

Principles of Adult Behavior

1. Be patient. No matter what.
2. Don’t badmouth: Assign responsibility, not blame. Say nothing of another you wouldn’t say to him.
3. Never assume the motives of others are, to them, less noble than yours are to you.
4. Expand your sense of the possible.
5. Don’t trouble yourself with matters you truly cannot change.
6. Expect no more of anyone than you can deliver yourself.
7. Tolerate ambiguity.
8. Laugh at yourself frequently.

hfreire

# Install QEMU OSX port with ARM support
sudo port install qemu +target_arm
export QEMU=$(which qemu-system-arm)

# Dowload kernel and export location
curl -OL \
https://github.com/dhruvvyas90/qemu-rpi-kernel/blob/master/kernel-qemu-4.1.7-jessie
export RPI_KERNEL=./kernel-qemu-4.1.7-jessie

# Download filesystem and export location

m-ou-se

$fs=1;
$fa=1;

servo_l = 24;
servo_w = 13;
servo_h = 21;

bolt_hole_diameter = 4.5;
servo_axis_diameter = 4;

rklaehn

package akkahttptest

import akka.actor.ActorSystem
import akka.http.Http
import akka.stream.FlowMaterializer
import akka.http.server._
import akka.http.marshalling.PredefinedToResponseMarshallers._
import akka.stream.scaladsl.{HeadSink, Source}

object Proxy extends App {