EXPOSING OVS STATISTICS FOR QUANTUM USERS

Tomer Shani19.6.13

Advanced Topics in Storage Systems

Spring 2013

Project goals

• In order to develop QoS for the cloud environment it is necessary to collect network statistics from the different network element.

• This project aims to expose network statistics from the “open virtual switch” so that further functionality can be added to the open stack environment.

Theoretical Overview

• OpenStack Quantum• Quantum Plugin Architecture• Open Virtual Switch• Proposed Solution

Quantum• Introduced as part of OpenStack Folsom release

(sept 2012)• Provides Network as a Service between interface

devices managed by other OpenStack services (most likely Nova).

• Allows users to create their own networks / network services and then attach interfaces to them.

• Quantum has a pluggable architecture to support many popular networking vendors and technologies.

Quantum – the big picture

Quantum – the details

• Quantum server – implements the RESTful API and routes requests to the correct plugin-in

• API abstractions:– Network: layer 2 network object,

attributes: admin state, name & subnets.– Subnet: layer 3 network object, attributes:

admin state, name, ip addr, subnet mask, dhcp, dns …– Port: NIC object, attributes:

network, device (virtual server), mac addr …

Quantum plugin architecture

Quantum plugin architecture• Plugin will typically update the

quantum database• Plugin agent runs on each compute

node, the agent gathers the configuration from the database and communicates directly with the local OVS instance.

• Quantum also provides an “extensibility” mechanism that enables extension of the Core API (resource/attribute/action)

• Quantum client - a command line API for accessing quantum functionality

Open virtual switch• OVS components (www.openvswitch.org):

– Kernel module implementing the data path– User space daemon “ovs-vswitchd” implementing the flow logic layer– User space daemon “ovsdb-server” which holds switch configuration– User space utilities, ovs-ofctl is the OpenFlow switch management

utility which also provides port statistics

Open virtual switch

• Available counters– Rx packets– Rx bytes– Rx drop– Rx errors– Rx crc errors– Rx frame– Rx overruns

– Tx packets– Tx bytes– Tx drop– Tx errors– Tx collisions

Design

Quantum

OVS plugin API

DB

Compute node

OVS instance

Core Utilities vswitchd ovs-ofctl db-server ovs-dpctl ovs_mod.ko ovs-appctl

CLI client

OVSPlugin agent

Design options - discussion

Pros• Data is retrieved as needed,

no constant access to database (saves network bandwidth)

• Data is (close to) “real-time” which may be critical for some applications

Cons• Plugin has longer access

time when compared to local database access.

• If multiple applications require the statistics, traffic is duplicate.

• No “natural” path for providing real-time data on request

• Should plugin-agent be polled or push data• Pros & Cons of “polling solution”

Hands on overview

• Setting up a work environment• Installing OpenStack• Configuring OpenStack • Creating a Cloud

Setting up a work environment

• First attempt: Dual 3 Ghz cores, 2 GB RAM, Ubuntu 12.10 Desktop, SLOW…..

• Second attempt: switched to server installation (no GUI), still sluggish..

• Third attempt: 8 * 3.4 Ghz cores, 4 GB RAM, much better

• Installed SMB to provide remote access to file system (coding).

• Enabled SSH to provide shell access.

Installing OpenStack

• Installed by utilizing Devstack, a shell script to build complete OpenStack development environments. – git clone https://

github.com/openstack-dev/devstack.git (have to install git first)

– cd devstack && ./stack.sh--------------------------------------------------------------------Horizon is now available at http://10.4.2.45/Keystone is serving at http://10.4.2.45:5000/v2.0/Examples on using novaclient command line is in exercise.shThe default users are: admin and demoThe password: 123456--------------------------------------------------------------------

Configuring OpenStack

• Now that we have access to the web server, we can start configuring a virtual networkBut that would be too easy…

• Default devstack installation configures nova networking (pre-quantum days)

• Modify localrc to enable quantum and run devstack again

tomers@ubuntu:~$ cat /opt/stack/devstack/localrc disable_service n-net…..enable_service quantum

And finally

Creating a network

Add a virtual host

Add a virtual host - cont.

And we have a network

Network objects

Quantum client

Generating traffic

It works !

Resources

• Openstackwww.openstack.org

• Devstackhttp://devstack.org/

• Openstack dcumentationhttp://docs.openstack.org/

• Open vSwitchhttp://openvswitch.org/

QUESTIONS?