q2K BHP
Black History Portal
THE BHP WIRE —
HIDDEN TRUTHS
GREENWOOD / BLACK WALL STREET WILMINGTON 1898 LITTLE ROCK NINE TUSKEGEE STUDY ROSEWOOD 1923 THE TUSKEGEE AIRMEN SENECA VILLAGE BLACK TOWNS GREENWOOD / BLACK WALL STREET WILMINGTON 1898 LITTLE ROCK NINE TUSKEGEE STUDY ROSEWOOD 1923 THE TUSKEGEE AIRMEN SENECA VILLAGE BLACK TOWNS
What's New!
THE JOURNEY THROUGH TIME
BHP HOME BEFORE AMERICA 1800–1936 1937–1957 1958–1980 1981–2000 2001–PRESENT

Explore Black History

Explore the people, places, events, achievements, struggles and stories that shaped our journey.

✊🏾

Civil Rights

Movements, leaders, victories and the continuing fight for equality.

⚙️

Black Inventors

Innovation, patents, science, technology and world-changing contributions.

🏆

Sports

Pioneers, champions, Negro Leagues, records, activism and excellence.

♟️

People

Meet the people whose lives, choices and achievements shaped the journey.

📍

Places

Black towns, communities, institutions and places where history happened.

📜

Events

Moments that changed communities, movements, institutions and the nation.

Enter a person, place, event, or topic.
MY'STORY

The MOVE Fire

This is a personal recollection on the Move fire on May 13, 1985 Philadelphia police fired thousands of rounds at the MOVE house, city officials approved dropping an explosive device on the roof, the resulting fire was allowed to burn, 11 people—including five children—died, and 61 homes were destroyed. Philadelphia City Council later called it a “brutal attack carried out by the City of Philadelphia on its own citizens” and acknowledged that no individual faced criminal consequences for the bombing. One timeline correction worth preserving for the BHP record: the major previous MOVE-police confrontation was August 8, 1978, about seven years before the bombing, not a year or two earlier. Officer James Ramp was killed, other police and firefighters were wounded, nine MOVE members were later convicted, and television cameras recorded police beating Delbert Africa during his arrest. The 1985 MOVE Commission later specifically criticized city planners for failing to adequately use lessons from that 1978 confrontation. And that actually strengthens the point you’re making: 1985 did not happen without precedent or institutional memory. There had already been a deadly confrontation with MOVE, years of conflict, negotiations and police involvement before Osage Avenue.

MORE →
BLACK FACTS
The Truths They Never Taught You...

Wilmington 1898 — An American Coup

Wilmington, North Carolina once had a thriving Black middle class and an elected interracial government. In 1898 white supremacists used violence to overthrow that government, kill Black residents and drive many others from the city.

MORE →
BHP gathered finds from its connected research sources. Showing the 4 strongest Black History matches.
← BACK TO RESULTS
Wikipedia

Linux Virtual Server

Linux Virtual Server
Original authorWensong Zhang
Developeret al.
ReleaseMay 1998; 28 years ago (1998-05)
Written inC
Operating systemLinux
Typeload balancing
LicenseGNU General Public License
Websitewww.linuxvirtualserver.org

Linux Virtual Server (LVS) is load balancing software for Linux kernel–based operating systems.

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.

Overview

[edit]
LVS as used by Wikimedia Foundation in 2022.

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 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 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

[edit]

Commonly 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 cluster

Examples

[edit]

Setting up a virtual HTTP server with two real servers:

# ipvsadm --add-service --tcp-service 192.168.0.1:80 --scheduler rr
# ipvsadm --add-server --tcp-service 192.168.0.1:80 --real-server 172.16.0.1:80 --masquerading
# ipvsadm --add-server --tcp-service 192.168.0.1:80 --real-server 172.16.0.2:80 --masquerading

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).[5]

Querying the status of the above configured LVS setup:

# ipvsadm --list --numeric
IP Virtual Server version 1.0.8 (size=65536)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.0.1:80 rr
  -> 172.16.0.2:80                Masq    1      3          1
  -> 172.16.0.1:80                Masq    1      4          0

See also

[edit]

References

[edit]
  1. ↑ "IPVS Software - Advanced Layer-4 Switching". linuxvirtualserver.org. 2011-02-08. Retrieved 2014-01-12.
  2. ↑ Wensong Zhang (2011-02-08). "KTCPVS Software - Application-Level Load Balancing". Linuxvirtualserver.org. Retrieved 2014-03-25.
  3. ↑ "Job Scheduling Algorithms in Linux Virtual Server". linuxvirtualserver.org. 2011-02-08. Retrieved 2013-11-24.
  4. ↑ "Linux Virtual Server: Load Balance Your Networked Services". bobcares.com. 2008. Retrieved 2013-11-24.
  5. ↑ Peter, Jeff. "Understanding Virtual Server". Retrieved 18 June 2023.
[edit]

Source: Wikipedia. Article content is retrieved live through the MediaWiki API.

Wikipedia

Linux Virtual Server

Linux Virtual Server (LVS) is load balancing software for Linux kernel–based operating systems. 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.

MORE →
No preview image
Wikipedia

IP Virtual Server

IPVS (IP Virtual Server) implements transport-layer load balancing, usually called Layer 4 LAN switching, as part of the Linux kernel. It's configured via the user-space utility ipvsadm(8) tool. IPVS is incorporated into the Linux Virtual Server (LVS), where it runs on a host and acts as a load balancer in front of a cluster of real servers. IPVS can direct requests for TCP- and UDP-based services to the real servers, and make services of the real servers appear as virtual services on a single IP address. IPVS is built on top of Netfilter. IPVS is merged into versions 2.4.x and newer of the Linux kernel mainline.

MORE →
Wikipedia

TurnKey Linux Virtual Appliance Library

The TurnKey Linux Virtual Appliance Library is a free open-source software project which develops a range of Debian-based pre-packaged server software appliances (also called virtual appliances). Turnkey appliances can be deployed as a virtual machine (a range of hypervisors are supported), in cloud computing services such as Amazon Web Services or installed in physical computers.

MORE →
No preview image
Wikipedia

Microsoft Virtual Server

Microsoft Virtual Server is a discontinued virtualization solution that facilitated the creation of virtual machines on the Windows XP, Windows Vista and Windows Server 2003 operating systems. Originally developed by Connectix, it was acquired by Microsoft prior to release. Virtual PC is Microsoft's related desktop virtualization software package. Virtual machines are created and managed through a Web-based interface that relies on Internet Information Services (IIS) or through a Windows client application tool called VMRCplus. The last version using this name was Microsoft Virtual Server 2005 R2 SP1. New features in R2 SP1 include Linux guest operating system support, Virtual Disk Precompactor, SMP (but not for the guest OS), x64 host operating system support, the ability to mount virtual hard drives on the host machine and additional operating systems support, including Windows Vista. It also provides a Volume Shadow Copy writer that enables live backups of the Guest OS on a Windows Server 2003 or Windows Server 2008 host. A utility to mount VHD images has also been included since SP1. Virtual Machine Additions for Linux are available as a free download. Officially supported Linux guest operating systems include Red Hat Enterprise Linux versions 2.1-5.0, Red Hat Linux 9.0, SUSE Linux and SUSE Linux Enterprise Server versions 9 and 10. Virtual Server has been succeeded by Hyper-V.

MORE →
TOPIC OF THE DAY

Greenwood / Black Wall Street

Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.

MORE →
TRIVIA QUESTION OF THE DAY

Who became the first Black woman to travel into space?

Mae Jemison, aboard Space Shuttle Endeavour in 1992.