Linux Virtual Server (LVS) is an open source load balancing software for Linux, it can be used to build highly scalable network services. The talk will give a brief introduction about the LVS project and its software, and outline over 14 years development and milestones, which includes community development and global collaboration, and finally conclude some personal experience from open source development of LVS.

1. LVS Project: 14
Years Development
and Experience
Wensong Zhang
The 11th Northeast Asia OSS Promotion Forum
2012.11.14
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2. About Me
 Wensong Zhang,
Ph.D.
 Working at Alibaba,
leading software
infrastructure team
 LVS founder &
developer
 Was the chief scientist
and co-founder of
TelTel, an associate
professor at NUDT,
the co-founder of
ChinaCluster, and Red
Hat Kernel Developer
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3. LVS Framework
The Linux Virtual Server
Project
 The goal of the Linux Virtual Server
project
 to provide a basic framework for building
highly scalable and highly available
network services using a large cluster of
commodity servers.
 http://www.LinuxVirtualServer.org
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4. LVS Framework
Framework
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5. LVS Framework
IP Virtual Server
 Implemented in the Linux kernel
 Three IP load balancing techniques
 Virtual Server via NAT
 Virtual Server via IP Tunneling
 Virtual Server via Direct Routing
 Ten scheduling algorithms
IPVS is an advanced Layer-4 switching
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6. Building Scalable Network Service using LVS
General Architecture
3 tiers
 Load balancer
 Server cluster
 Shared storage
 Clusters
 Web
 Cache
 Email, etc
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7. Characteristics of LVS
Characteristics
 LVS extends Linux kernel to support
three IP load balancing techniques
 Ten scheduling algorithms
 High scalability (up to 100 nodes)
 High availability
 Supporting most TCP and UDP
services, no modifications to either
clients or servers
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8. Characteristics of LVS
Compared to Other
Commercial Products
 More IP load balancing techniques
 Multiple scheduling algorithms
 State synchronization
 A robust and stable code base, a large
user and developer base.
 Reliability proven in big real world
applications
 Free to everyone
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9. Comments from LVS Users
 “ We tried virtually all of the commercial load
balancers, LVS beats them all for reliability, cost,
manageability, you-name-it”
Jerry Glomph Black, Director, Internet & Technical Operations, Real
Networks, Seattle Washington, USA
http://marc.theaimsgroup.com/?1=linux-virtual-server&m=95385809030794&w=2
 “I can say without a doubt that lvs toasts F5/BigIP
solutions, at least in our real world
implementations. I wouldn’t trade a good lvs box for
a Cisco Local Director either”
Drew Streib, Information Architect, VA Linux Systems, USA
http://marc.theaimsgroup.com/?1=linux-virtual-server&m=95385694529750&w=2
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10. Some Sites using LVS
 QQ.com has deployed thousands of LVS
in the production
 Alibaba has used about 500 LVS systems
 Baidu.com has used about 500 too
 sourceforge.net & linux.com
 real.com
 IBM and EDS use LVS in their solutions
 One of largest PC manufacturers
 There is about tens of thousands of LVS
deployment on this planet
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11. LVS Development
 I got my first Linux CD at the end of 1995, mainly
installed Linux for fun, later used Linux servers in
some SI solutions.
 May 1998: the first version of LVS was released
as a patch for Linux kernel 2.0, which only
supports VS/NAT and Round-Robin scheduling,
very simple!
 Later, added more scheduling algorithms, and
included some bug fixes, and so on.
 Nov 1998: implemented the VS/IPTunneling load
balancing.
 May 1999: implemented the VS/DirectRouting
load balancing, then ported it to the Linux kernel
2.2
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12. LVS Development (cont’d)
 More and more people joined the project.
 May 2000: ported to the Linux kernel 2.4
 Sep 2002: ported to the Linux kernel 2.5
 Oct 2003: included into the Linux kernel 2.5
devel trunk, and into the Linux kernel 2.4
stable branch too.
 Nov 2003: Linux kernel 2.4.23 includes LVS
 Dec 2003: Linux kernel 2.6.0 includes LVS
 Nov 2008: Google engineers helped to add
IPv6 support
 Feb 2010: SCTP protocol support was added
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13. LVS Global Collaboration
 Source: WIRED Magazine, Vol. 6, 2004
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14. Some Insights
 It’s better to do things well first, then reward
follows.
 Open source is a good way to get more users,
users will test and give feedbacks.
 Open source is also a good way to collect
requirements.
 Through open source development, we can get
help from a lot of developers and talents, we can
improve our skills through collaboration.
Software quality is improved as well.
 Open source can make our code to have much
longer lifecycle.
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15. Some Insights (Cont’d)
 The ways that users run our software
usually beyond our imagination.
 Do not think that it’s too hard to do open
source, just write software and open
source it.
 It’s important to write documents for
open source projects, especially the
QuickStart.
 It’s also very important to give
acknowledgements to every contribution,
then community can grow.
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16. Collateral
 The Linux Virtual Server Project
(http://www.LinuxVirtualServer.org)
 wensong@linux-vs.org
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17. Q & A
Thanks!
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