[openstack]-01- basic introduction

technology

virtualization

Cloud computing

• A business model （ Resource pool ）
• Distribute on demand , Scale at any time
• Over the Internet
  The implementation of cloud computing needs to rely on virtualization technology

OpenStack

openstack It is piled up by many open source projects , Corresponding IaaS（ Infrastructure as a service ）. The computing function relies on VMware.

project

• Nova Computing services
• Neutron Network services
• Cinder Block storage , Disk mount
• Glance Image services
• Keystone Certification services
• Swift Object storage , Storage file system

OpenStack Evolution

Version update is fast

• 2010.6 OpenStack Be born
• 2010.10 Austin Nova Swift
• 2011.2 Bexar Glance
• 2011.4 Cactus
• 2011.10 Diablo Keystone Horizon
• 2012.4 Essex
• 2012.10 Folsom Quantum Cinder
• 2013.4 Grizzy
• 2013.10 Havana Quantum->Neutron
• 2014.4 Icehouse
• 2014.10 Juno
• 2015.4 Kilo
• 2105.10 Liberty

OpenStack characteristic

OpenStack The development language is Python

Components are passed between components api Interaction , Components interact with each other through message queues

OpenStack Architecture design features ： No center 、 Distributed 、 Asynchronous execution （ The sender sends the message to the message queue ）、 Pluggable and configurable 、Restful API
OpenSatck Architecture advantages ： Flexible deployment 、 Easy to expand 、 Easy integration

Docker： It provides a container for program running , At the same time, ensure that these containers are isolated from each other

The underlying technology （ virtualization ）

Computing virtualization

CPU Privilege level ：ring0【 Kernel mode 】、ring1、ring2、ring3【 User mode 】 （x86）
The smaller the number, the higher the privilege level
Computing virtualization solves multiple problems cpu The virtual

hypervisor Virtualization Manager

Virtualization Manager VMM

1. Semi virtualization TYPE2
   Modify the kernel of the guest operating system
2. Full virtualization
   Hardware assisted virtualization TYPE1
   One cpu Virtual into multiple cpu
   The guest operating system does not need to be modified

The performance of full virtualization is better than that of semi virtualization

libvirt

libvirt It's a free set 、 Open source support Linux Under the mainstream virtualization management program C function library , To include KVM Various virtualization hypervisors, including, provide a set of convenience 、 Reliable interface .
Key terms ：

• node Node： A physical machine , There may be multiple virtual clients running on it
• Domain Domain： stay Hypervisor An instance of a client operating system running on

Network virtualization

Data link layer ： Provide reliable point-to-point data direct link
The network layer ： Address assignment among the nodes of the network

Software Defined Network SDN
Use software to drive the underlying hardware , Handle the layout of the data plane

Open vSwitch

• abbreviation OVS. Commonly used in virtualization platforms , Provide layer-2 switching function for virtual machines , Support Xen/XenServer,KVM,VirtualBox Multi support virtualization technology .
• Support openflow agreement , You can use any support openflow The controller pair of the protocol OVS Remote management control .

Important concepts ：

• Bredge： Represents an Ethernet switch , One or more can be created in a host Bridge equipment

Linux Bridge
The function is similar to that of a layer-2 switch , stay linux The kernel , High stability

General components

L Use after version Python3
L Previous use python2

Rest

• rest It's an architectural style , Its core is resource orientation , be based on http agreement
• HTTP In the agreement , Four verbs of expression ：GET、POST、PUT、DELETE
• GET Used to obtain resources 、POST Used to create a new resource 、PUT Used to update or create new resources 、DELETE Used to delete resources

WSGI

WSGI web server gateway interface

• WSGI It's a norm , It describes web server How to communicate with web application Interaction 、web application How to handle requests
• WSGI contain Server、Middleware、Application

Paste Deployment

Paste Deployment （ abbreviation PD） It's a WSGI tool kit

MariaDB

relational database
openstack Core projects keystone、cinder、glance、neutron、nova It is used to configure persistent relational databases

RabbitMQ

MQ Is the consumer - A typical representative of the producer model , Information is constantly written in the message stream of one end network , The other end can read or subscribe to messages in the queue
Main noun ：

• exchanger exchange
• queue queue
• Binder bind
  opensatck Middle module cinder、neutron、nova The internal communication between such projects is through AMQP Protocol implementation , Message by RabbitMQ Forward as middleware