jfeilbach

TCP tuning

The most important TCP tuning areas since kernel 4.9 are:

• packet pacing
• dynamic TSO sizing
• TCP small queues
• BBR TCP congestion algorithm

Definitions

• Gb = gigabit

wmertens

Thought experiment: Redux-like stateless server

Description

We describe a model for client-server processing where the Redux model is used to minimize stateful code. This should allow live-reloading server code, and make it possible to share code (e.g. optimistic updating) between client and server.

Dramatis Personae

• Assume a server consisting of multiple worker processes that do not share memory and may be running on multiple hosts.
  • Workers have middleware, root reducers and an app state object
• Workers can be dynamically added and removed

gnachman

on write_to_file(this_data, target_file, append_data)
	try
		set the target_file to the target_file as string
		set the open_target_file to open for access file target_file with write permission
		if append_data is false then set eof of the open_target_file to 0
		write this_data to the open_target_file starting at eof
		close access the open_target_file
		return true
	on error
		try

jjb

This all applies to Ruby 2.1. In some cases a setting is not available in 2.0, this is noted. There is also a different with 1.9, 1.8, and REE --- these are not noted.

All the relevant code is in https://github.com/ruby/ruby/blob/master/gc.c

RUBY_HEAP_MIN_SLOTS

default: 10000

The number of heap slots to start out with. This should be set high enough so that your app has enough or almost enough memory after loading so that it doesn't have to allocate more memory on the first request (althogh this probably isn't such a big deal for most apps).

(todo: figure out how big a slot is. i think the answer can be infered from this code.)

enjalot

  #make a hook
    store.hook 'change', 'collection.*.foo', (docId, value, op, session, backend) ->
      model = store.createModel()
      #logic

  
  #setup the hook method
  store.hook = (method, pattern, fn) ->
    store.shareClient.use 'after submit', (shareRequest, next) ->
      {opData} = shareRequest

kates

ag "sometext" --nogroup | awk '{print substr($1,1,index($1,":")-1);}' | xargs -I {} sed -i .bak -e 's/sometext/anothertext/g' {}

zenkay

Ruby, RVM and Mountain Lion

Key problems

Mountain Lion (10.8) has three main difference compared to Lion (10.7):

• XCode 4.4 does not install Command Line Tools by default
• X11 isn't available anymore
• The installed version of OpenSSL has some bugs

How to work around

dstroot

#!/bin/bash
# from here: http://www.codingsteps.com/install-redis-2-6-on-amazon-ec2-linux-ami-or-centos/
# and here: https://raw.github.com/gist/257849/9f1e627e0b7dbe68882fa2b7bdb1b2b263522004/redis-server
###############################################
# To use: 
# wget https://raw.github.com/gist/2776679/04ca3bbb9f085b192f6aca945120fe12d59f15f9/install-redis.sh
# chmod 777 install-redis.sh
# ./install-redis.sh
###############################################
echo "*****************************************"

jesseproudman

require 'rubygems'; require 'active_resource'; require 'new_relic_api'

servers = File.open("server_count.txt", "r").first.to_i
instances_per_server = 6
cpu_burn_for_system = 1000.0 * 0.20

NewRelicApi.api_key = "<Your API Key>"

account             = NewRelicApi::Account.find(:first);
application         = account.applications[3];

mathiasbynens

#!/bin/bash

if [ "$1" = "-h" -o "$1" = "--help" -o -z "$1" ]; then cat <<EOF
appify v3.0.1 for Mac OS X - http://mths.be/appify
Creates the simplest possible Mac app from a shell script.

Appify takes a shell script as its first argument:

    `basename "$0"` my-script.sh