LVS is a free and open-source project started by Wensong Zhang in May 1998, subject to the requirements of the GNU General Public License (GPL), version 2. The mission of the project is to build a high-performance and highly available server for Linux using clustering technology, which provides good scalability, reliability and serviceability.
The major work of the LVS project is now to develop advanced IP load balancing software (IPVS), application-level load balancing software (KTCPVS), and cluster management components.
IPVS: an advanced IP load balancing software implemented inside the Linux kernel. The IP Virtual Server code is merged into versions 2.4.x and newer of the Linux kernel mainline.[1]
KTCPVS: implements application-level load balancing inside the Linux kernel, as of February 2011[update] still under development.[2]
LVS can be used for building highly scalable and highly available network services, such as web, email, media and VoIP services, and integrating scalable network services into large-scale reliable e-commerce or e-government applications. LVS-based solutions already have been deployed in many real applications throughout the world, including Wikipedia.
The LVS components depend upon the Linux Netfilter framework, and its source code is available in the net/netfilter/ipvs subdirectory within the Linux kernel source. LVS is able to handle UDP, TCP layer-4 protocols as well as FTP passive connection by inspecting layer-7 packets. It provides a hierarchy of counters in the /proc directory.
The userland utility program used to configure LVS is called ipvsadm, which requires superuser privileges to run.
Schedulers
LVS implements several balancing schedulers, listed below with the relevant source files:[3]
Round-robin (ip_vs_rr.c)
Weighted round-robin (ip_vs_wrr.c)
Least-connection (ip_vs_lc.c)
Weighted least-connection (ip_vs_wlc.c)
Locality-based least-connection (ip_vs_lblc.c)
Locality-based least-connection with replication (ip_vs_lblcr.c)
LVS director: load balancer that receives all incoming client requests for services and directs them to a specific "real server" to handle the request
Real servers: nodes that make up an LVS cluster which are used to provide services on the behalf of the cluster
Client computers: computers requesting services from the virtual server
VIP (Virtual IP address): the IP address used by the director to provide services to client computers
RIP (Real IP address): the IP address used to connect to the cluster nodes
DIP (Directors IP address): the IP address used by the director to connect to network of real IP addresses
CIP (Client IP address): the IP address assigned to a client computer, that it uses as the source IP address for requests being sent to the cluster
Examples
Setting up a virtual HTTP server with two real servers:
ipvsadm -A -t 192.168.0.1:80 -s rr ipvsadm -a -t 192.168.0.1:80 -r 172.16.0.1:80 -m ipvsadm -a -t 192.168.0.1:80 -r 172.16.0.2:80 -m
The first command assigns TCP port 80 on IP address192.168.0.1 to the virtual server. The chosen scheduling algorithm for load balancing is round-robin (-s rr). The second and third commands are adding IP addresses of real servers to the LVS setup. The forwarded network packets shall be masked (-m).
Querying the status of the above configured LVS setup:
IBM eServer BladeCenter, Linux, and Open Source: Blueprint for e-business on demand (includes LVS as a component)
January 13, 2023
linux, virtual, server, load, balancing, software, linux, kernel, based, operating, systems, official, logooriginal, author, wensong, zhangdeveloper, initial, releasemay, 1998, years, 1998, written, incoperating, systemlinuxtypeload, balancinglicensegnu, gener. Linux Virtual Server LVS is load balancing software for Linux kernel based operating systems Linux Virtual ServerLVS official logoOriginal author s Wensong ZhangDeveloper s et al Initial releaseMay 1998 24 years ago 1998 05 Written inCOperating systemLinuxTypeload balancingLicenseGNU General Public LicenseWebsitewww wbr linuxvirtualserver wbr orgLVS is a free and open source project started by Wensong Zhang in May 1998 subject to the requirements of the GNU General Public License GPL version 2 The mission of the project is to build a high performance and highly available server for Linux using clustering technology which provides good scalability reliability and serviceability Contents 1 Overview 1 1 Schedulers 2 Glossary 3 Examples 4 See also 5 References 6 External linksOverview Edit LVS as used by Wikimedia Foundation in 2020 The major work of the LVS project is now to develop advanced IP load balancing software IPVS application level load balancing software KTCPVS and cluster management components IPVS an advanced IP load balancing software implemented inside the Linux kernel The IP Virtual Server code is merged into versions 2 4 x and newer of the Linux kernel mainline 1 KTCPVS implements application level load balancing inside the Linux kernel as of February 2011 update still under development 2 LVS can be used for building highly scalable and highly available network services such as web email media and VoIP services and integrating scalable network services into large scale reliable e commerce or e government applications LVS based solutions already have been deployed in many real applications throughout the world including Wikipedia The LVS components depend upon the Linux Netfilter framework and its source code is available in the net netfilter ipvs subdirectory within the Linux kernel source LVS is able to handle UDP TCP layer 4 protocols as well as FTP passive connection by inspecting layer 7 packets It provides a hierarchy of counters in the proc directory The userland utility program used to configure LVS is called ipvsadm which requires superuser privileges to run Schedulers Edit LVS implements several balancing schedulers listed below with the relevant source files 3 Round robin ip vs rr c Weighted round robin ip vs wrr c Least connection ip vs lc c Weighted least connection ip vs wlc c Locality based least connection ip vs lblc c Locality based least connection with replication ip vs lblcr c Destination hashing ip vs dh c Source hashing ip vs sh c Shortest expected delay ip vs sed c Never queue ip vs nq c Maglev hashing ip vs mh c Glossary EditCommonly used terms include the following 4 LVS director load balancer that receives all incoming client requests for services and directs them to a specific real server to handle the request Real servers nodes that make up an LVS cluster which are used to provide services on the behalf of the cluster Client computers computers requesting services from the virtual server VIP Virtual IP address the IP address used by the director to provide services to client computers RIP Real IP address the IP address used to connect to the cluster nodes DIP Directors IP address the IP address used by the director to connect to network of real IP addresses CIP Client IP address the IP address assigned to a client computer that it uses as the source IP address for requests being sent to the clusterExamples EditSetting up a virtual HTTP server with two real servers ipvsadm A t 192 168 0 1 80 s rr ipvsadm a t 192 168 0 1 80 r 172 16 0 1 80 m ipvsadm a t 192 168 0 1 80 r 172 16 0 2 80 m The first command assigns TCP port 80 on IP address 192 168 0 1 to the virtual server The chosen scheduling algorithm for load balancing is round robin s rr The second and third commands are adding IP addresses of real servers to the LVS setup The forwarded network packets shall be masked m Querying the status of the above configured LVS setup ipvsadm L n IP Virtual Server version 1 0 8 size 65536 Prot LocalAddress Port Scheduler Flags gt RemoteAddress Port Forward Weight ActiveConn InActConn TCP 192 168 0 1 80 rr gt 172 16 0 2 80 Masq 1 3 1 gt 172 16 0 1 80 Masq 1 4 0See also Edit Linux portal Free and open source software portalIP Virtual Server Netfilter and nftables Network schedulerReferences Edit IPVS Software Advanced Layer 4 Switching linuxvirtualserver org 2011 02 08 Retrieved 2014 01 12 Wensong Zhang 2011 02 08 KTCPVS Software Application Level Load Balancing Linuxvirtualserver org Retrieved 2014 03 25 Job Scheduling Algorithms in Linux Virtual Server linuxvirtualserver org 2011 02 08 Retrieved 2013 11 24 Linux Virtual Server Load Balance Your Networked Services bobcares com 2008 Retrieved 2013 11 24 External links EditOfficial website Linux Virtual Server Configuration Wiki IBM eServer BladeCenter Linux and Open Source Blueprint for e business on demand includes LVS as a component Retrieved from https en wikipedia org w index php title Linux Virtual Server amp oldid 1054474988, wikipedia, wiki, book, books, library,
