History of 4th January

46 BC - Titus Labienus defeats Julius Caesar in the Battle of Ruspina.
274 - St Eutychian begins his reign as Catholic Pope
871 - Battle at Reading: Ethelred of Wessex beats Danish invasion army
1357 - Flemish earl Louis & Luxembourg Duke Wenceslaus sign peace treaty
1490 - Anna of Brittany announces that all those who would ally with the king of France will be considered guilty of the crime of lese-majesty.
1493 - Columbus left new world on return from 1st voyage
1519 - -6] 1st Altenburger sermon (Luther & Karl von Miltitz)
1570 - Spanish viceroy Alva banishes Zutphen City's only physician, Joost Sweiter, "because he is a Jew"
1642 - King Charles I with 400 soldiers attacks the English parliament
1698 - Most of the Palace of Whitehall in London, the main residence of the English monarchs, is destroyed by fire.
1717 - Netherlands, England & France sign Triple Alliance
1725 - Benjamin Franklin arrives in London [OS=Dec 24 1724]
1754 - Columbia University founded, as Kings College (NYC)
1762 - England declares war on Spain & Naples
1780 - Snowstorm hit Washington's army at Morristown, NJ
1781 - Andre Méchain discovers M80 (globular cluster in Scorpio)
1790 - Pres Washington delivers 1st "State of the Union"
1832 - Insurrection of Trinidad negroes
1843 - Gaetano Donizetti's opera "Don Pasquale," premieres in Paris
1843 - Royal Academy (Technical Hague court) Delft opens
1847 - Samuel Colt sells his first revolver pistol to the United States government.
1854 - The McDonald Islands are discovered by Captain William McDonald aboard the Samarang.
1861 - Pres Buchanan appoints a fast on account of threatened succession
1861 - US Ft Morgan, Mobile, seized by Alabama
1862 - -Jan 17th) Battle of Ft Hindman, AK (Arkansas Post)
1862 - Romney Campaign-Stonewall Jackson occupies Bath
1863 - 4 wheeled roller skates patented by James Plimpton of NY
1865 - The New York Stock Exchange opens its first permanent headquarters at 10-12 Broad near Wall Street in New York City.
1878 - Sofia is emancipated from Ottoman rule.
1881 - Johannes Brahms' "Academic Festival Overture" premieres, Breslau
1883 - Ontario Rugby Football Union (forerunner of CFL) forms
1884 - Last sighting of an eastern cougar (Ontario)
1884 - The Fabian Society is founded in London.
1885 - Dr W W Grant of Iowa, performs 1st appendectomy (on Mary Gartside, 22)
1887 - Thomas Stevens is 1st man to bicycle around the world (SF-SF)
1893 - US pres Cleveland grants amnesty to Mormon polygamy
1894 - France ratifies Duple Alliance with Russia
1896 - AFL charters Actors' National Protective Union, NYC
1896 - Following Mormon abandonment of polygamy, Utah admitted as 45th state
1898 - 1st installment of William Dean Howell's "Life & Letters" appears
1902 - Hugh Trumble takes a hat-trick v England at the MCG
1903 - Topsy, an elephant, was electrocuted by Thomas Edison during the War of Currents campaign.
1904 - Stanley Cup: Ottawa Silver 7 beat Winnipeg Rowing Club, 2 games to 1
1904 - Supreme Court rules Puerto Ricans cannot be denied admission to US
1906 - South Africa beat England by one wicket, their 1st Test win
1907 - George Bernard Shaw's "Don Juan in Hell," premieres in London
1912 - Smallest earth-moon distance this century, 356,375 km center-to-ctr
1912 - The Scout Association is incorporated throughout the British Commonwealth by Royal Charter.
1915 - 1st elected Jewish governor, Moses Alexander, takes office in Idaho
1915 - Trans-Caucausus Russian defeat Turkish troops
1920 - 1st Black baseball league, National Negro Baseball League, organizes
1920 - Amsterdam actors decide to strike for retirement benefits
1921 - Eugene O'Neill's "Diff'rent," premieres in NYC
1923 - 1st broadcast of "Barn Dance Show" (WBAP - Ft Worth Texas)
1923 - Lenin's "Political Testament" calls for removal of Stalin
1925 - French psychologist Emil Coué brings his self-esteem therapy to US "Every day in every way I am getting better & better"
1926 - Theodorus Pangalos resigns as Greek dictator
1932 - Bradman scores 167 for Australia v South Africa at the MCG
1932 - British East Indies Viceroy Willingdon arrests Gandhi & Nehru
1932 - State of siege proclaimed in Honduras
1934 - 1st Dutch talkie movie, Jan Teunissen's "Willem of Orange," premieres
1935 - Bob Hope 1st heard on network radio as part of "The Intimate Revue"
1935 - Ft Jefferson National Monument, Fla established
1936 - Billboard magazine publishes its 1st music hit parade
1936 - Grimmett becomes world record wicket taker with no 190 v S Afr
1939 - Frieda Wunderlich elected 1st woman dean of a US graduate school
1939 - Hermann Goering appoints Reinhard Heydrich head of Jewish Emigration
1941 - Resistance fighters counter d'Estienne d'Orves/Jan Doornik, 1st meet
1941 - Sergey Rachmaninov's "Symphonie Dances," premieres in Philadelphia
1942 - NFL Pro Bowl: Chi Bears beats NFL All-Stars 35-24
1942 - Premier Churchill & General Marshall fly to Florida
1942 - Rogers Hornsby is 14th player selected to the Hall of Fame
1943 - Thomas Mann completes his tetralogy, "Joseph & His Brothers"
1944 - Ralph Bunche appointed 1st Negro official in US State Department
1945 - Germans execute resistance fighters in Amsterdam
1945 - US jeep-aircraft carrier Ommaney Bay sinks after kamikaze attack
1947 - "Park Avenue" closes at Shubert Theater NYC after 72 performances
1947 - "Show Boat" closes at Ziegfeld Theater NYC after 417 performances
1948 - Burma declares independence from UK
1951 - During Korean conflict, Chinese forces capture Seoul
1953 - KTSM TV channel 9 in El Paso, TX (NBC) begins broadcasting
1954 - Elvis Presley records a 10 minute demo in Nashville
1954 - Soap Opera "The Brighter Day" premieres
1957 - "Blondie" situation comedy premieres on NBC TV (later on CBS)
1957 - Dodgers buy 44 passenger twin-engine airplane for $775,000
1958 - Sputnik 1 reenters atmosphere & burns up
1959 - Luna 1 (Mechta) becomes 1st craft to leave Earth's gravity
1960 - European Free Trade Association forms in Stockholm
1961 - Longest recorded strike ends-33 yrs-Danish barbers' assistants
1962 - 1st automated (unmanned) subway train (NYC)
1962 - New York City introduces a train that operates without a crew on-board.
1963 - Soviet Luna (4) reaches Earth orbit but fails to reach Moon
1965 - LBJ's "Great Society" State of the Union Address
1966 - Doug Walters scores second Test century in his second Test
1966 - WFLD TV channel 32 in Chicago, IL (IND) begins broadcasting
1968 - Duck hunter accidentally shoots endangered whooping crane in Texas
1968 - Leo Fender sells Fender Guitars for $13 million
1969 - "Fig Leaves Are Falling" closes at Broadhurst NYC after 4 perfs
1969 - France begins arms embargo against Israel
1970 - Beatles last recording session at EMI studios

1970 - KC Chiefs beat Oakland Raiders 17-7 in AFC championship game
1970 - Minn Vikings beat Cleve Browns 27-7 in NFC championship game
1970 - NYC transit fare rises from 20 cents to 30 cents, new larger tokens used
1970 - Walter Cronkite ends hosting weekly documentary
1971 - Congressional Black Caucus organizes
1971 - Dr Melvin H Evans inaugurated as 1st elected governor of Virgin Is
1971 - Ohio agrees to pay $675,000 to relatives of Kent State victims
1971 - Philadelphia's Veteran Stadium dedicated
1972 - Rose Heilbron becomes the first female judge to sit at the Old Bailey in London.
1974 - Nixon refuses to hand over tapes subpoenaed by Watergate Committee
1975 - "Good News" closes at St James Theater NYC after 16 performances
1975 - "Gypsy" closes at Winter Garden Theater NYC after 120 performances
1975 - "Over Here" closes at Shubert Theater NYC after 341 performances
1975 - Ford Executive Order on CIA Activities within the US (No 11828)
1975 - Ice thickness measured at 4776 m, Wilkes Land, Antarctica
1975 - Montreal Canadiens shutout Washington Capitals 10-0
1976 - "Candide" closes at Broadway Theater NYC after 740 performances
1976 - "Home Sweet Homer" opens & closes at Palace Theater NYC
1977 - Mary Shane hired by Chic White Sox as 1st woman TV play-by-play
1980 - President Carter announces US boycott of Moscow Olympics
1981 - "Frankenstein" opens & closes on Broadway
1981 - "Peter Pan" closes at Lunt-Fontanne Theater NYC after 578 performances
1981 - 69th Australian Mens Tennis: B Teacher beats Kim Warwick (75 76 63)
1981 - British police arrest Peter Sutcliffe, the "Yorkshire Ripper"
1982 - Bryant Gumbel became co-host of NBC's "Today Show"
1982 - Chris Wallace becomes co-anchor of the Today Show
1982 - Golden Gate Bridge closed for 3rd time by fierce storm
1982 - ABC Direction Network (57 affiliates) & ABC Rock Network (40 affiliates) become the 5th & 6th ABC radio network
1983 - US Football League holds its 1st player draft
1984 - "Night Court" starring Harry Anderson premieres on NBC TV
1984 - Edmonton beats Minnesota 12-8 highest-scoring modern NHL game
1986 - David Boon's second Test century, 131 v India at Adelaide
1986 - NCAA basketball's David Robinson blocks a record 14 shots
1987 - 16 die in a train crash in Chase Md
1989 - Comet Tempel 1 at perihelion
1989 - US F-14s shoot down 2 Libyan jet fighters over Mediterranean
1989 - VP Bush is 1st since VP Van Buren to declare himself president
1991 - AT&T workers in Newark accidentally snap a cable
1991 - Fu Mingxia, 12, of China wins World Swimming Championships gold medal
1991 - Iraq agrees to send Aziz to Geneva to meet Baker on Jan 9th
1991 - Jan Krzystof Bielecki becomes premier of Poland
1992 - 8th largest wrestling crowd (60,000-Tokyo Dome)
1993 - 7th largest wrestling crowd (63,500-Tokyo Dome)
1994 - 10th largest wrestling crowd (58,000-Tokyo Dome)
1995 - Newt Gingrich (R) becomes speaker of the House
1996 - "Father" opens at Criterion Theater NYC for 52 performances
1998 - "Funny Thing Happened," closes at St James NYC after 715 perform
1998 - "Ivanov," closes at Vivian Beaumont Theater NYC after 51 performances
1998 - "Triumph of Love," closes at Royale Theater NYC
1998 - Wilaya of Relizane massacres in Algeria: over 170 are killed in three remote villages.
1998 - A massive ice storm hits eastern Canada and the northeastern United States, continuing through January 10 and causing widespread destruction.
1999 - Former professional wrestler Jesse Ventura is sworn in as governor of Minnesota.
1999 - Gunmen open fire on Shiite Muslims worshipping in an Islamabad mosque, killing 16 people and injuring 25.
2001 - Rapper Vanilla Ice spends night in jail after allegedly ripping out some of his wife's hair during a row
2004 - Britney Spears has her surprise marriage annulled less than 55 hours after tying the knot with childhood friend Jason Alexander at the Little White Wedding Chapel in Las Vegas
2004 - Spirit, a NASA Mars Rover, lands successfully on Mars at 04:35 UTC.
2006 - Prime Minister Ariel Sharon of Israel suffers a second, apparently more serious stroke. His authority is transferred to acting Prime Minister Ehud Olmert.
2007 - The 110th United States Congress convenes, electing Nancy Pelosi as the first female Speaker of the House in U.S. history.

History of 3rd January

236 - St Anterus ends his reign as Catholic Pope
269 - St Felix I begins his reign as Catholic Pope
936 - Duke Alberik II of Spoleto appoints his son Pope Leo VII
1338 - Jacob of Arteveld elected mayor of Ghent
1407 - Bloody battles between Hoeksen & Kabeljauwen in Dordrecht
1431 - Joan of Arc handed over to the bishop
1496 - Leonardo da Vinci unsuccessfully tests a flying machine.
1521 - Martin Luther excommunicated by Pope Leo X from the Roman Catholic Church
1638 - Dutch Premier Van Joost speaks of "Hostage rights of Aemstel"
1638 - Schouwburg Theater, the 1st in Amsterdam, opens
1667 - Resistance of Androsovo in Russia-Poland
1667 - Russia & Poland sign Truce of Androsovo
1746 - Bonnie Prince Charlies army leaves Glasgow, [NS=1/14]
1749 - Benning Wentworth issues the first of the New Hampshire Grants, leading to the establishment of Vermont.
1750 - Tax revolt in Haarlem Neth
1752 - East Indies invasion "Geldermalsen" leaves at Malakka: 92 killed
1777 - Washington defeats British at Battle of Princeton, NJ
1780 - Danish national anthem "Kong Kristian...," 1st sung
1823 - Stephen F. Austin receives a grant of land in Texas from the government of Mexico.
1825 - Scottish factory owner Robert Owen buys 30,000 acres in Indiana as site for New Harmony utopian community
1831 - 1st US building & loan association organized, Frankford, Penn
1833 - Britain seizes control of Falkland Islands in South Atlantic
1834 - The government of Mexico imprisons Stephen F. Austin in Mexico City.
1840 - 1st deep sea sounding
1847 - California town of Yerba Buena renamed San Francisco
1848 - Joseph Jenkins Roberts is sworn in as the first president of the independent African Republic of Liberia.
1852 - 1st Chinese arrive in Hawaii
1861 - Delaware legislature rejects proposal to join Confederacy
1861 - US Ft Pulaski & Ft Jackson, Savannah, seized by Georgia
1862 - Romney Campaign-Stonewall Jackson moves north from Winchester
1865 - Con Orem & Hugh O'Neill box 193 rounds before darkness ends match
1868 - Meiji Restoration returns authority to Japan's emperors
1870 - Brooklyn Bridge construction begins; completed May 24, 1883
1871 - Oleomargarine patented by Henry Bradley, Binghamton, NY
1872 - 1st patent list issued by US Patent Office
1888 - 1st wax drinking straw patented, by Marvin C Stone in Washington DC
1889 - Admissions convention meets in Ellensburg, WA, asks for statehood
1890 - 1st US college-level dairy school opens at University of Wisconsin
1896 - Emperor Wilhelm congratulates Pres Kruger on the Jameson Raid
1899 - The first known use of the word automobile, was seen in an editorial in The New York Times.
1900 - Gerhart Hauptmanns "Schluck und Jau," premieres in Berlin
1900 - Perihelion Passage
1902 - Reg Duff 104 on Test debut, v England at MCG
1910 - British miners strike for 8 hour working day
1911 - US postal savings bank inaugurated
1912 - South Pacific RR offers to bring Liberty Bell to Exposition, free
1914 - Kelman/Cushing/Heath' musical "Sari," premieres in NYC
1918 - US employment service opens as a unit of Dept of Labor
1920 - Arthur Honegger's "Chant de Nigamon," premieres
1920 - NY Yankees purchase Babe Ruth from Red Sox for $125,000
1921 - Turkey makes peace with Armenia
1922 - 1st living person identified on a US coin (Thomas E Kirby) on the Alabama Centennial half-dollar
1924 - British egyptologist Howard Carter finds sarcophagus of Tutankhamun
1925 - Mussolini dissolves Italian parliament/becomes dictator
1925 - Benito Mussolini announces he is taking dictatorial powers over Italy.
1926 - Greek gen Theodorus Pangulos names himself dictator
1929 - 27 year old William S Paley becomes CBS pres
1929 - Bradman scores 112 v England at MCG - his 1st Test century
1931 - Nels Stewart of Montreal Maroons scores 2 goals in 4 sec (record)
1932 - Martial law is declared in Honduras to stop revolt by banana workers fired by United Fruit.
1933 - Minnie D. Craig becomes the first female elected as Speaker of the North Dakota House of Representatives, the first female to hold a Speaker position anywhere in the United States.
1938 - March of Dimes established to fight polio
1939 - Gene Cox becomes 1st girl page in US House of Representatives
1940 - WPG-AM in Atlantic City NJ consolidates with WBIL & WOV as "new" WOV
1941 - Canada & US acquire air bases in Newfoundland (99 yr lease)
1941 - Italian counter offensive in Albania
1941 - Sergei Rachmaninov's "Symphonic Dances" premieres in Philadelphia
1942 - American-British-Dutch-Australian (ABDA) Command forms
1943 - 1st missing persons telecast (NYC)
1943 - Canadian Army troops arrive in North Africa
1944 - World War II: Top Ace Major Greg "Pappy" Boyington is shot down in his Corsair by Captain Masajiro Kawato flying a Zero.
1945 - Allies land on west coast of Burma, conquer Akyab
1945 - British Premier Winston Churchill visits France
1945 - Cato-Meridian School, NY, installs germicidal lamps in every room
1945 - Greek General Plastiras forms government
1945 - John Patrick's "Hasty Heart," premieres in NYC
1945 - US aircraft carriers attack Okinawa
1947 - 1st opening session of Congress to be televised
1947 - William Dawson becomes 1st black to head congressional committee
1948 - Bradman completes dual Test tons (132 & 127*) v India MCG
1949 - "Colgate Theater" dramatic anthology series premieres on NBC TV
1951 - 9 Jewish Kremlin physicians "exposed" as British/US agents
1951 - Fred Wilt wins AAU Sullivan Memorial Trophy (US athlete of 1950)
1952 - "Dragnet" with Jack Webb premieres on NBC TV
1952 - Australia beat W Indies by one wicket at the MCG, last stand 38
1953 - Frances Bolton and her son, Oliver from Ohio, become the first mother and son to serve simultaneously in the U.S. Congress.
1955 - Jose Ramon Guizado becomes president of Panama
1956 - A fire damages the top part of the Eiffel Tower.
1957 - 1st electric watch introduced, Lancaster Pa
1958 - Edmund Hillary reaches South Pole overland
1958 - Lindsay Kline takes a hat-trick v South Africa at Cape Town
1958 - The West Indies Federation is formed.
1959 - Alaska admitted as 49th US state
1961 - Adam Clayton Powell elected Chairman of House Education & Labor
1961 - US breaks diplomatic relations with Cuba
1962 - Ground is broken for the Houston Astrodome
1962 - Pope John XXIII excommunicates Fidel Castro
1963 - WOUB TV channel 20 in Athens, OH (PBS) begins broadcasting
1964 - Jack Paar Show, shows a clip of the Beatles singing "She Loves You"
1966 - Floyd B McKissick, named national director of CORE

1967 - "Tonight Show" is shortened from 105 to 90 minutes
1967 - Carl Wilson of the Beach Boys is indicted for draft evasion
1967 - WJAN TV channel 17 in Canton, OH (IND) begins broadcasting
1969 - John Lennon's "2 Virgins" album declared pornographic in NJ
1969 - Rep Adam Clayton Powell Jr seated by Congress
1970 - "Jimmy" closes at Winter Garden Theater NYC after 84 performances
1970 - "Mame" closes at Winter Garden Theater NYC after 1508 performances
1970 - Marxist government takes over in Congo
1970 - WHAG TV channel 25 in Hagerstown, MD (NBC) begins broadcasting
1971 - "President's Daughter" closes at Billy Rose Theater NYC after 72 perfs
1971 - Baltimore Colts beat Oakland Raiders 27-17 in AFC championship game
1971 - Dallas Cowboys beat SF '49ers 17-10 in NFC championship game
1973 - George Steinbrenner III buys Yankees from CBS for $12 million
1974 - Arias Navarro succeeds Carrero Blanco as premier of Spain
1974 - Burma accepts its constitution
1974 - Gold hits record $121.25 an ounce in London
1974 - Miguel Pinero's "Short Eyes," premieres in NYC
1974 - NY Yankees sign Bill Virdon as manager
1976 - US performs nuclear test at Nevada Test Site
1977 - Apple Computers incorporate
1977 - Lindy McDaniel retires with 2nd most pitching appearances (987 games)
1978 - Chandrasekar takes 6-52 & 6-52 at MCG in Indian innings win
1980 - Gold hits record $634 an ounce
1981 - 55th Australian Womens Tennis: H Mandlikova beats W Turnbull (60 75)
1981 - Cleveland Cavaliers retire jersey # 34, Austin Carr
1981 - Greg Chappell scores 204 v India at the SCG
1981 - Mary Terstegge Meagher swims female record 100 m butterfly (58.91)
1983 - Tony Dorsett sets NFL record with 99-yd rush, Dallas vs Minnesota
1984 - Syria frees captured US pilot after appeal from Jesse Jackson
1985 - Azharuddin scores 110 in 1st Test innings
1985 - Israel govt confirms resettlement of 10,000 Ethiopian Jews
1987 - "Oh Coward!" closes at Helen Hayes Theater NYC after 56 performances
1987 - "Smile" closes at Lunt-Fontanne Theater NYC after 48 performances
1987 - Rock & Roll Hall of Fame inducts 1st female artist Aretha Franklin
1987 - Singer/Miss America Vanessa Williams marries Ramon T Hervey in NYC
1988 - Israel orders 9 Palestinian "instigators" deported from W Beirut
1988 - Margaret Thatcher becomes longest-serving British PM this century
1989 - Jim & Tammy Bakker return to TV (Oy Vey!)
1989 - Russian newspaper Izvestia gets its 1st commercial advertisement
1990 - Panama's leader Gen Manuel Noriega surrenders to US authorities
1991 - Israel reopens consulate in USSR after 23 years
1991 - LA King Wayne Gretzky scores his 700th goal against NY Islanders
1992 - 32 Cubans defect to the US via helicopter
1992 - Boon completes 11 Test Cricket century, 129* v India at Sydney
1993 - "Catskills on Broadway" closes at Lunt-Fontanne NYC after 452 perfs
1993 - "Christmas Carol" closes at Broadhurst Theater NYC after 22 perfs
1993 - "Lost in Yonkers" closes at Richard Rodgers NYC after 780 perfs
1993 - "Secret Garden" closes at St James Theater NYC after 706 performances
1993 - "Tommy Tune Tonite!" closes at Gershwin NYC after 10 performances
1993 - Junk bond king Michael Milkin is released from jail after 22 months
1994 - "Gray's Anatomy" closes at Beaumont Theater NYC after 13 performances
1994 - 100s killed in Venezuela in prison revolt
1994 - Tupolev-154M crashes at Irkutsk, Siberia: 122 killed
1994 - 35-foot-tall Chief Wahoo, trademark of Indians on top of Stadium since 1962, is taken down, to be moved to Jacob's Field
1997 - Bryant Gumbel co-hosted his final "Today" show on NBC-TV
1997 - Eddo Brandes takes ODI hat-trick v England at Harare
1997 - Zimbabwe clean-sweep ODI series v England 3-0
1997 - The People's Republic of China announces it will spend $27.7 billion USD to fight erosion and pollution in the Yangtze and Yellow river valleys.
1998 - "Side Show," closes at Richard Rodgers NYC after 91 performances
1998 - Grandpa Jones suffers a stroke
1999 - Israel detains, and later expels, 14 members of Concerned Christians.
1999 - The Mars Polar Lander was launched.
2004 - Flight 604, a Boeing 737 owned by Flash Airlines, an Egyptian airliner, plunges into the Red Sea, killing all 148 people on board.
2007 - National Express has its worst ever coach crash just outside Heathrow Airport.
2009 - Israeli ground forces invade Gaza.

An Introduction to SQL Server Clustering

 

If your mission-critical SQL Server should experience a motherboard failure, how long will it be down? One hour, four hours, a day, or longer? How much will this cost your business in lost sales or productivity? And perhaps even more important to you, what will it do to your stress level?

 

Being a SQL Server DBA can be demanding and stressful, especially as the success of your company is often a function of your SQL Server’s uptime. While we, as DBAs, have some control over the uptime of our SQL Servers, we don’t have full control. There is not much we can do if a motherboard fails on a server, other than be prepared.

 

As you may already be aware, there is one way to help boost your SQL Server’s uptime, and that is by clustering SQL Servers. This way, should one SQL Server fail in the cluster, another clustered server will automatically take over, keeping downtime to minutes, instead of hours or more.

 

The purpose of this article is to introduce you to SQL Server clustering, along with its pros and cons. If you are considering clustering SQL Server to help reduce potential downtime, this article is a good place to start.

 

 

What is Clustering?

 

Clustering can be best described as a technology that automatically allows one physical server to take over the tasks and responsibilities of another physical server that has failed. The obvious goal behind this, given that all computer hardware and software will eventually fail, is to ensure that users running mission-critical applications will have little or no downtime when such a failure occurs. Downtime can be very expensive, and our goal as DBA is to help reduce it as much as possible.

 

More specifically, clustering refers to a group of two or more servers (generally called nodes) that work together and represent themselves as a single virtual server to a network. In other words, when a client connects to clustered SQL Servers, it thinks there is only a single SQL Server, not more than one. When one of the nodes fails, its responsibilities are taken over by another server in the cluster, and the end-user notices little, if any differences before, during, and after the failover.

 

Microsoft added clustering features to its operating system when they introduced Windows NT Server 4.0 Enterprise Edition several years ago. The actual clustering feature was called MSCS (Microsoft Clustering Server). While some brave folks actually put the software into production, I personally avoided it as it was not as dependable as Microsoft led you to believe. Also, about this same time, SQL Server 6.5 Enterprise Edition was released, allowing it to be clustered. This was a very crude attempt at clustering SQL Server that was rarely implemented in the real world.

 

Later, when SQL Server 7.0 became available, there were major improvements in SQL Server clustering, but no way was it still good enough, as Windows NT 4.0 Server Enterprise MSCS was still being used at its foundation, and it just wasn’t good enough for maintaining high-availability servers.

 

Fortunately, Microsoft’s second attempt at clustering, now called the Microsoft Cluster Service, in Windows 2000 Advanced Server and Windows 2000 Datacenter Server, is much better. While I won’t claim it is perfect, at least I now am willing to use it to cluster mission-critical SQL Servers. Cluster Service not only works well when clustering SQL Server 7.0, it is even better if you want to cluster SQL Server 2000, which has greatly enhanced clustering support.

 

One very important aspect of clustering that often gets overlooked is that it is not a complete backup system for your applications. It is only one part of a multi-part strategy required to ensure minimum downtime and 100% recoverability.

 

The main benefits that clustering provides is the ability to recover from failed server hardware (excluding the shared disk) and failed software, such as failed services or a server lockup. It is not designed to protect data, to protect against a shared disk array from failing, to prevent hack attacks, to protect against network failure, or to prevent SQL Server from other potential disasters, such as power outages or acts of God.

 

Clustering is just one part of an entire strategy needed to help reduce application downtime. You will also need to purchase a shared disk array (more on this later) that offers redundancy, make tape backups, put the server behind a firewall, make sure your network connections have redundancy, use battery backup, and locate the server in a secure facility, among many other steps you can take. So don’t think that clustering is all you need for creating a highly available SQL Server. It is just one part.

 

 

What Are the Types of Clustering?

 

When you decide you want to cluster SQL Server, you have a choice of configuring what is called Active/Active or an Active/Passive cluster. Each has its own pros and cons. Let’s look at each, in the context of a two-node SQL Server cluster.

 

An Active/Active SQL Server cluster means that SQL Server is running on both nodes of a two-way cluster. Each copy of SQL Server acts independently, and users see two different SQL Servers. If one of the SQL Servers in the cluster should fail, then the failed instance of SQL Server will failover to the remaining server. This means that then both instances of SQL Server will be running on one physical server, instead of two.

 

As you can imagine, if two instances have to run on one physical server, performance can be affected, especially if the server’s have not been sized appropriately.

 

An Active/Passive SQL Server cluster refers to a SQL Server cluster where only one instance of SQL Server is running on one of the physical servers in the cluster, and the other physical server does nothing, other that waiting to takeover should the primary node should fail.

 

From a performance perspective, this is the better solution. On the other hand, this option makes less productive use of your physical hardware, which means this solution is more expensive.

 

Personally, I prefer an Active/Passive configuration as it is easier to set up and administer, and overall it will provide better performance. Assuming you have the budget, this is what I recommend.

 

 

Two- or Four-Node Clustering?

 

SQL Server can be clustered using two nodes (using Windows 2000 Advanced Server), or it can be clustered using more than two nodes (using Windows 2000 Datacenter). Since I don’t personally have any experience is three or four node clustering, I won’t be discussing it here. But for the most part, what I say about two-node clustering also applies to three- or four-node clustering.

 

 

 

 

 

 

How Does Clustering Work?

 

Clustering is a very complex technology, so I will focus here on the big picture. In a two-cluster node, one of the SQL Servers is referred to as the primary node, and the second one is referred to as the secondary node. In an Active/Passive cluster design, SQL Server will run on the primary node, and should the primary node fail, then the secondary node will take over.

 

When you build a two-node cluster using Windows 2000 Advanced Server and Microsoft Clustering Service, each node must be connected to a shared disk array using either SCSI cables or fibre channel.

 

Typically, this shared disk array is a stand-alone unit that houses a RAID 5 or RAID 10 disk array. All of the shared data in the cluster must be stored on this disk array, otherwise when a failover occurs, the secondary node in the cluster cannot access it. As I have already mentioned earlier, clustering does not help protect data or the shared disk array that it is stored on. Because of this, it is very important that you select a shared disk array that is very reliable and includes fault tolerance.

 

Besides both servers being connected to a shared disk array, both nodes of the cluster are also connected to each other via a private network. This private network is used for each node to keep track of the status of the other node. For example, if the primary node experiences a hardware failure, the secondary node will detect this and will automatically initiate a failover.

 

So how do clients who are accessing SQL Server know what to do when a failover occurs in a cluster? This is the cleverest part of Microsoft Cluster Service. Essentially what happens in a SQL Server cluster is that you assign SQL Server its own virtual name and virtual TCP/IP address. This name and address is shared by both of the servers in the cluster.

 

Typically, a client will connect to the SQL Server cluster using the virtual name used by the cluster. And as far as a client is concerned, there is only one physical SQL Server, not two. Assuming that the primary node of the SQL Server cluster is the node running SQL Server on an Active/Passive cluster design, then the primary node will respond to the client’s requests. But if the primary node fails, and failover to the secondary node occurs, the cluster will still retain the same SQL Server virtual name and TCP/IP address, although now a new physical server will be responding to client’s requests.

 

During the failover period, which can last several minutes (the exact amount of time depends on the number and sizes of the databases on SQL Server, and how active they are), clients will be unable to access SQL Server, so there is a small amount of downtime when failover occurs.

 

How the client software reacts to the failover process depends on the software. Some software will just wait the failover out, and when the failover has completed, it will continue just as nothing had happened. Some software will present a message box on the screen, describing a lost connection. Other client software will not know what to do, and users may have to exit, and then reload the client before they can access SQL Server again.

 

As part of the testing process when implementing a SQL Server cluster, it is important to find out how all of the client software that connects to SQL Server reacts to a failover. This way, you can inform your users of what to expect, so they are better able to deal with it when it does occur.

 

Once a failover occurs, you will want to find out what caused the failover, and then take the necessary action and correct the problem. Once the problem has been fixed, the next step is to failover SQL Server back to the primary node from the secondary node. You can schedule to do this anytime, preferably when user activity is light on the system.

 

What are the Pros and Cons of Clustering?

 

Implementing SQL Server clustering is a big decision, and one fraught with many gochas. Before you undertake such a large and important project, you will want to carefully evaluate the pros and cons of clustering, which include, but are not limited to:

 

 

Pros of SQL Server Clustering

 

*     Reduces downtime to a bare minimum.

*     Permits an automatic response to a failed server or software. No human intervention is required.

*     It allows you to perform upgrades without forcing users off the system for extended periods of time.

*     It allows you to reduce downtime due to routine server, network, or database maintenance.

*     Clustering doesn't require any servers to be renamed. So when failover occurs, it is relatively transparent to end-users.

*     Failing back is quick, and can be done whenever the primary server if fixed and put back on-line.

*     In some cases, clustering can be used to increase the scalability of an application. For example, if a current cluster is getting too busy, another server could be added to the cluster to expand the resources and help boost the performance of the application.

 

Cons of Clustering

 

*     More expensive than other failover alternatives, such as log shipping or stand-by servers.

*     Requires more set up time than other alternatives.

*     Requires more on-going maintenance than other alternatives.

*     Requires more experienced DBAs and network administrators.

 

 

Setting Up and Managing a SQL Server Cluster

 

This topic could fill a book, but unfortunately, there is not enough room here for that. So what I will do here is just cover the basics so you have some feel for what you face.

 

Based on my experience with SQL Server clustering, you should keep the following in mind:

 

*     Buy an approved cluster system and have it delivered to you 4-8 weeks before you plan to implement it. This will give you lots of time to learn about it and work out any problems. I guarantee you, you will have problems.

*     Consider attending training on clustering, or at least bringing in a consultant in early in the game to help you plan your implementation. If you have never done this before, you will need all the help you can get. Unfortunately, there is not a lot of good information available on clustering, so you will have to fend for yourself more than you usually do.

*     Once your clusters is up and running, test it thoroughly as possible using the same databases and clients you intend to use on it when you start production.

*     Thoroughly document everything as you build your cluster.

*     Develop a plan to regularly monitor the cluster.

*     Develop a plan to regularly test the cluster to ensure that it will failover as expected.

*     Develop a formal backup and recovery plan, and test it.

*     Create a disaster recovery plan for what you intend to do should you loose all the nodes in your cluster.

 

Implementing and managing a cluster is complex. You will want to assign a team of top network and database administrators to implement and manage it.