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Haiyong Wang

Outline

• A brief introduction to Chef• A brief introduction to Ruby• Latching VS Locking

A brief Introduction to Chef

Haiyong Wang

Outline

• What is chef• Architecture and installing• Using chef

What is Chef

With Chef, you write abstract definitions as source code to describe how you want each part of your infrastructure to be built, and then apply those descriptions to individual servers.

Chef Provides

• Provisioning– Kickstart Jumpstart

• Configuration Management– Recipes , knife, cookbook

• Systems Integration

Chef Provides

Different Flavors of Chef

• Chef Solo• Chef Client and Chef Server• Hosted Chef

Chef Client and Chef Server

Installing

• Servers and Workstation– http://

wiki.opscode.com/display/chef/Installing+Chef+Server+on+Debian+or+Ubuntu+using+Packages

Installing

• Clients– http://

wiki.opscode.com/display/chef/Installing+Chef+Client+on+Ubuntu+or+Debian

Installing

• Important files– Validation.pem– client.pem– knife.rb– Client.rb

Using chef

• Important concepts– Git– Cookbook– Recipe– Run_list

Using chef

cookbook Recipes

configure

bootstrap

Using Chef

• Useful links– Cookbook fast start• http://wiki.opscode.com/display/chef/Cookbook+Fast+

Start+Guide

– Github cookbook• https://github.com/opscode-cookbooks• https://github.com/infochimps-cookbooks

– Cookbook community• http://community.opscode.com/

Using Chef

• Hbase

Question ?

A brief introduction to Ruby

Check the syntax

• ruby –c

• rake test

Assignment#assigning a local variable#no type declaration#no semicolonx = 1x, y, z = “100”, 200, 300# global variable$amout = 1#const variableName = “Floydene Wallup”name = “Floydene Wallup”

Basic Arithmetic

5/2 #=> 25/2.0 #=> 2.5(1+2)* 3 #=> 9

irb(main):001:0>3+4 #=> 7irb(main):002:0> 7-3 #=>4irb(main):005:0>3**4 #=> 81irb(main):007:0> x= 12 #=> 12irb(main):008:0> x+=1 irb(main):012:0> Math.sqrt(16) #=> 4

strings'single quoted' # => "single quoted" "double quoted" # => "double quoted" 'It\'s alive' # => "It's alive!" "1 + 2 = 5" # => "1 + 2 = 5"

th = "Hello world“th[0..5] #=>Helloth[-5..-1] #=>world

Embedded

x = "Bob""Hi, #{x}" # => "Hi, Bob"'Hello, #{x}' # => "Hello, #{x}"

Bool variables

true # => true false # => false nil # => nil !true # => false !false # => true !nil # => true !!true # => true !!false # => false !!nil # => false!!0 # => true

Arrays

x = ["a", "b", "c"]# => ["a", "b", "c"] x[0] # => "a" (zero is the first index) x.first # => "a" x.last # => "c" x + ["d"] # => ["a", "b", "c", "d"]x # => ["a", "b", "c"] x = x + ["d"] # => ["a", "b", "c", "d"] x # => ["a", "b", "c", "d"]

Hash

# => { "first_name => "Bob", "last_name" => "Jones" }h = { "first_name" => "Bob", "last_name" => "Jones"}

h.keys # => ["first_name", "last_name"] h["first_name"] # => "Bob" h["last_name"] # => "Jones" h["age"] = 23h.keys # => ["first_name", "age", "last_name"] h.values # => ["Jones", "Bob", 23]

perl-style regular expressions

"I believe" =~ /I/ # => 0"I believe" =~ /lie/ # => 4"I am human" =~ /bacon/ # => nil"I am human" !~ /bacon/ # => true/give me a ([0-9]+)/ =~ "give me a 7" # => 0

Conditional statement

if false # this won't happen else if nil # this won't either else # code here will runend

x = "dog"case x when "fish" # this won't happen when "dog", "cat", "monkey" # this will run else # the else is an optional catch-all end

Method

def do_something_useless( first, second) puts "You gave me #{first} and #{second}"

end

do_something_useless( "apple", "banana") # => "You gave me apple and banana"

do_something_useless 1, 2# => "You gave me 1 and 2"

Function of the following code?

n=120 primes = Array.new for i in 0..n-2

primes[i] = i+2 end index = 0 while primes[index]**2 <= primes.last

prime = primes[index] primes = primes.select { |x| x == prime || x%prime != 0 } index += 1

end p primes

Question ?

Locking and Latching

Locking and Latching

Latching• Purpose

– exclusive access to memory structures

Locking• Purpose

– share the same resource if compatible

– enforce exclusive access if incompatible.

Locking and Latching

Latching• Jurisdiction

– temporary memory objects– B-Tree index

Locking• Jurisdiction

– database objects – tables, data blocks

Locking and Latching

Latching• Acquisition

– willing-to-wait – no-wait

Locking• Acquisition

– Null– row share– row exclusive– Share– share row exclusive– exclusive

Locking and Latching

Latching• Scope

– instance level– Information kept in memory– visible to the local instance

Locking• Scope

– database-level– Information kept in database– visible to all instances

accessing the database

Locking and Latching

Latching• Complexity

– Lightweight– Simple instructions– port specific

Locking• Complexity

– Heavyweight– series of instructions with

context switches

Locking and Latching

Latching• Duration

– briefly – microseconds

Locking• Duration

– an extended period of time– transactional duration

Locking and Latching

Latching• Queue

– not queued

Locking• Queue

– queued

Locking and Latching

Latching• Deadlock

– No deadlocks

Locking• Deadlock

– deadlocks

Thank you