In political science, rollback is the strategy of forcing a change in the major policies of a state, usually by replacing its ruling regime. It contrasts with containment, which means preventing the expansion of that state; and with détente, which means a working relationship with that state. Most of the discussions of rollback in the scholarly literature deal with United States foreign policy toward Communist countries during the Cold War. The rollback strategy was tried, but was not successful in Korea in 1950 and in Cuba in 1961. The political leadership of the United States discussed the use of rollback during the uprising of 1953 in East Germany and the Hungarian Revolution of 1956, but decided against it to avoid the risk of Soviet intervention or a major war.
Rollback of governments hostile to the U.S. took place in World War II (against Italy 1943, Germany 1945 and Japan 1945), Afghanistan (against the Taliban 2001) and Iraq (against Saddam Hussein 2003). When directed against an established government, rollback is sometimes called "regime change".
The term rollback was popularized in the 1940s and the 1950s, but the term is much older. Some Britons, opposed to Russian oppression against Poland, proposed in 1835 a coalition that would be "united to roll back into its congenial steppes and deserts the tide of Russian barbarism." Scottish novelist and military historian John Buchan in 1915 wrote of the American Indian Wars, "I cast back to my memory of the tales of Indian war, and could not believe but that the white man, if warned and armed, would rollback [sic] the Cherokees."
The notion of military rollback against the Soviet Union was proposed by conservative strategist James Burnham and other strategists in the late 1940s, and by the Truman Administration against North Korea in the Korean War. Much debated was the question whether the U.S. should pursue a rollback strategy against Communism in Eastern Europe in 1953–56; the decision was not to.
Instead of military rollback, the U.S. began a program of long-term psychological warfare to delegitimize Communist and pro-Communist regimes and help insurgents. These attempts began as early as 1945 in Eastern Europe, including efforts to provide weapons to independence fighters in the Baltic States and Ukraine. Another early effort was against Albania in 1949, following the defeat of Communist forces in the Greek Civil War that year. In this case, a force of agents was landed by the British and Americans to try to provoke a guerrilla war, but it failed. The operation had already been betrayed to the Soviets by the British double-agent Kim Philby, and led to the immediate capture or killing of the agents.
The Truman administration saw the Soviet Union as the main adversary and began discussing how to launch coordinated political, non-military actions to roll back its presence in Eastern Europe without a hot war. The rollback policy failed. Historian Stephen Long argues that the key policy makers, especially the State Department's Policy Planning Staff, failed to devise a coherent strategy. Furthermore Long blames the disordered bureaucracy that impaired and strategically dislocated the operations planned by the Office of Policy Coordination.
In the Korean War, the United States and the United Nations officially endorsed a policy of rollback—the destruction of the North Korean government—and sent UN forces across the 38th parallel to take over North Korea. The rollback strategy, however, caused the Chinese to intervene, and US forces were pushed back to the 38th parallel. The failure of a complete rollback despite its advocacy by MacArthur, moved the United States to commit to the alternate strategy of containment. The U.S. had moved from a strategy of containment, to one of rollback, and returned to containment in late 1950-early 1951.
In 1954, the Pentagon wanted President Dwight D. Eisenhower to endorse a rollback strategy in Asia against Soviet advances. No, He replied, "the time of a significant rollback was far in the future."
Republican spokesman John Foster Dulles took the lead in promoting a rollback policy. He wrote in 1949:
We should make it clear to the tens of millions of restive subject people in Eastern Europe and Asia, that we do not accept the status quo of servitude [that] aggressive Soviet Communism has imposed on them, and eventual liberation is an essential and enduring part of our foreign policy.
The 1952 Republican Party's national platform reaffirmed this position; when Dwight D. Eisenhower was elected, he appointed Dulles as Secretary of State. Eisenhower adviser Charles Douglas Jackson coordinated psychological warfare against Communism. Radio Free Europe, a private agency funded by Congress, broadcast attacks on Communism directed at Eastern Europe. A strategic alternative to rollback was containment, and the Eisenhower Administration adopted containment through National Security Council document NSC 162/2 in October 1953; this effectively abandoned the rollback efforts in Europe.
Eisenhower relied on clandestine CIA actions to undermine hostile small governments and used economic and military foreign aid to strengthen governments supporting the American position in the Cold War. A successful rollback was the CIA's Operation Ajax in August 1953, in collaboration with the British, which assisted the Iranian military in their anti-democratic restoration of the Shah.
Eisenhower's decision not to intervene during the Hungarian Uprising of 1956 made containment a safer strategy than rollback, which risked a nuclear confrontation with the Soviet Union.
Both Eisenhower and Dulles focused more attention on the Suez Crisis which, due to the Protocol of Sèvres, unfolded simultaneously. The Suez Crisis played an extremely important role in hampering the US response to the crisis in Hungary. The problem was not, contrary to widespread belief, that Suez distracted US attention from Hungary, but that it made the condemnation of Soviet actions very difficult. As Vice President Richard Nixon later explained: "We couldn't on one hand, complain about the Soviets intervening in Hungary and, on the other hand, approve of the British and the French picking that particular time to intervene against Gamal Abdel Nasser."
Lemann notes that when he wrote that in 1984, he thought the Reaganites were living in a fantasy world. But in 2016, he says, that passage represents "a fairly uncontroversial description of what Reagan actually did."
The "rollback" movement gained significant ground, however, in the 1980s, specifically against the Soviet Union, as the Reagan administration urged on by The Heritage Foundation and other influential conservatives began to channel weapons to movements such as the Mujahedin in Afghanistan, the Contras in Nicaragua and others in anti-communist armed movements Angola, Cambodia and other nations, and launched a successful invasion of Grenada in 1983 to protect American residents and reinstate constitutional government following a coup by what Reagan called "a brutal gang of leftist thugs,"—this invasion was presented as a dramatic example of rolling back a Communist government in power. Moscow worried that it might be next.
Reagan's interventions in the Third World came to be known as the Reagan Doctrine. It was applied especially to pro-Communist regimes in Central America, as in Grenada and Nicaragua, and was also extended to Angola, Afghanistan, and Cambodia.
Critics argued that the Reagan Doctrine led to so-called blowback and an unnecessary intensification of Third World conflict. On the other hand, in the various rollback battlefields, the Soviet Union made major concessions and eventually had to abandon the Soviet-Afghan war. Jessica Martin writes, "Insofar as rollback is concerned, American support for rebels, especially in Afghanistan, at the time helped to drain Soviet coffers and tax its human resources, contributing to that nation's overall crisis and eventual disintegration."
This rollback strategy played out in Third World nations that the Soviets had penetrated. Together with heavy pressure on the Soviet military, exemplified by the Star Wars missile defense system, the Soviet system cracked, with the dissolution of the Soviet Union in 1991. Nationalistic unrest in the USSR exploded in 1989, as all of the Eastern European satellites broke free and rolled back Communism relatively peacefully, with the exception of the violent revolution in Romania. East Germany merged with West Germany.
Between 1988 and 1991, the fifteen Soviet Socialist Republics declared their laws superior to those of the Soviet Union, and the Soviet Union ceased to exist on December 26, 1991, as Communism was rolled back across all of Europe.
After the invasion of Kuwait on 2 August 1990, a coalition of Western militaries deployed to protect Saudi Arabia from Iraqi dictator Saddam Hussein. After several months of negotiation and diplomacy, an American-led force started air and ground operations to dislodge the invasion and return Kuwait to sovereignty. While the campaign successfully freed Kuwait, many military leaders and American politicians called for a full invasion of Iraq to replace Saddam Hussein. According to many, the consequences of the decision not to remove Hussein from power in 1991 significantly contributed to the decisions of the Administration of George W. Bush, son of the former president, to invade Iraq in 2003.
President George W. Bush's policies were similar to those of his father. Following the September 11 attacks, his administration, along with a NATO coalition, undertook a war in Afghanistan to stop the al-Qaida terrorist group responsible for the attacks. Bush told Congress:
Similarly, Bush opposed the regime of Saddam Hussein in Iraq, labeling the regime as part of an "axis of evil", which also included Iran and North Korea. Additionally, the administration believed Hussein possessed nuclear weapons. As a result, in March 2003, the U.S. military invaded Iraq and overthrew Hussein's regime.
In September 2014, after ISIL had outraged public opinion by beheading two American journalists and had seized control of large portions of Syria and Iraq against ineffective opposition from American allies, President Barack Obama announced a new objective for a rollback policy in the Middle East. He announced:
As of 2017, the administration of President Donald Trump has continued the Obama administration's policies against ISIL.
Back-arc basins are geologic basins, submarine features associated with island arcs and subduction zones. They are found at some convergent plate boundaries, presently concentrated in the western Pacific Ocean. Most of them result from tensional forces caused by oceanic trench rollback (the oceanic trench is wandering in the seafloor direction) and the collapse of the edge of the continent. The arc crust is under extension or rifting as a result of the sinking of the subducting slab. Back-arc basins were initially a surprising result for plate tectonics theorists, who expected convergent boundaries to be zones of compression, rather than major extension. However, they are now recognized as consistent with this model in explaining how the interior of Earth loses heat.Bedford, Texas
Bedford is a city located in northeast Tarrant County, Texas, in the "Mid-Cities" area between Dallas and Fort Worth. It is a suburb of Fort Worth. The population was 46,979 at the 2010 census. Bedford is part of the Hurst-Euless-Bedford Independent School District.Compensating transaction
The execution of a business process consists of one or more transactions. Each transaction may consist of several individual operations yet, as a whole, it moves the system between consistent states.
There are two groups of systems where compensating transaction may be applied:
1. In the context of a database this is often easily achieved using transactions and the commit/rollback mechanism. Compensating transaction logic could be implemented as additional on top of database supporting commit/rollback. In that case we can decrease business transaction granularity.
2. For systems without a commit/rollback mechanism available, one can undo a failed transaction with a compensating transaction, which will bring the system back to its initial state. Typically, this is only a workaround which has to be implemented manually and cannot guarantee that the system always ends in a consistent state. The system designer may need to consider what happens if the compensating transaction also fails.
Compensating transactions are also used in case where a transaction is long lived (commonly called Saga Transactions), for instance in a business process requiring user input. In such cases data will be committed to permanent storage, but may subsequently need to be rolled back, perhaps due to the user opting to cancel the operation. Unlike conventional rollbacks, specific business logic will typically be required to roll back a long lived transaction and restore the system to its original state. This type of transaction differs from distributed transactions (often implemented using the two-phase-commit protocol), because although both types of transactions can result in multiple data stores being updated, compensating transactions allows for the updates to span a long period of time.
Compensating transactions are often designed into Web services that participate in the execution of business processes that are part of a service-oriented architecture solution.Containment
Containment is a geopolitical strategy to stop the expansion of an enemy. It is loosely related to the term cordon sanitaire which was later used to describe the geopolitical containment of the Soviet Union in the 1945s. The strategy of "containment" is best known as a Cold War foreign policy of the United States and its allies to prevent the spread of communism after the end of World War II.
As a component of the Cold War, this policy was a response to the Soviet Union's move to increase communist influence in Eastern Europe, Asia, Africa and Latin America. Containment represented a middle-ground position between detente (relaxation of relations) and rollback (actively replacing a regime).
The basis of the doctrine was articulated in a 1946 cable by U.S. diplomat George F. Kennan during the post-WWII administration of U.S. President Harry S. Truman. As a description of U.S. foreign policy, the word originated in a report Kennan submitted to U.S. Defense Secretary James Forrestal in 1947, which was later used in a magazine article.Lift hill
A lift hill, or chain hill, is an upward-sloping section of track on a roller coaster on which the roller coaster train is mechanically lifted to an elevated point or peak in the track. Upon reaching the peak, the train is then propelled from the peak by gravity and is usually allowed to coast throughout the rest of the roller coaster ride's circuit on its own momentum, including most or all of the remaining uphill sections. The initial upward-sloping section of a roller coaster track is usually a lift hill, as the train typically begins a ride with little speed, though some coasters have raised stations that permit an initial drop without a lift hill. Although uncommon, some tracks also contain multiple lift hills.
Lift hills usually propel the train to the top of the ride via one of two methods: a chain lift involving a long, continuous chain which trains hook on to and are carried to the top; or a drive tire system in which multiple motorized tires (known as friction wheels) push the train upwards. A typical chain lift consists of a heavy piece of metal called a chain dog, which is mounted onto the underside of one of the cars which make up the train. This is in place to line up with the chain on the lift hill.
The chain travels through a steel trough, and is normally powered by one or more motors which are positioned under the lift hill. Chain dogs underneath each train are engaged by the chain and the train is pulled up the lift. Anti-rollback dogs engage a rack (ratcheted track) alongside the chain to prevent the train from descending the lift hill. At the crest of the lift, the chain wraps around a gear wheel where it begins its return to the bottom of the lift; the train is continually pulled along until gravity takes over and it accelerates downhill. The spring-loaded chain and anti-rollback dogs will disengage themselves as this occurs.Oceanic trench
Oceanic trenches are topographic depressions of the sea floor, relatively narrow in width, but very long. These oceanographic features are the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth measured is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.Online transaction processing
In Online transaction processing (OLTP), information systems typically facilitate and manage transaction-oriented applications.
The term "transaction" can have two different meanings, both of which might apply: in the realm of computers or database transactions it denotes an atomic change of state, whereas in the realm of business or finance, the term typically denotes an exchange of economic entities (as used by, e.g., Transaction Processing Performance Council or commercial transactions.) OLTP may use transactions of the first type to record transactions of the second.
OLTP has also been used to refer to processing in which the system responds immediately to user requests. An automated teller machine (ATM) for a bank is an example of a commercial transaction processing application. Online transaction processing applications have high throughput and are insert- or update-intensive in database management. These applications are used concurrently by hundreds of users. The key goals of OLTP applications are availability, speed, concurrency and recoverability. Reduced paper trails and the faster, more accurate forecast for revenues and expenses are both examples of how OLTP makes things simpler for businesses. However, like many modern online information technology solutions, some systems require offline maintenance, which further affects the cost-benefit analysis of an online transaction processing system.
OLTP is typically contrasted to OLAP (online analytical processing), which is generally characterized by much more complex queries, in a smaller volume, for the purpose of business intelligence or reporting rather than to process transactions. Whereas OLTP systems process all kinds of queries (read, insert, update and delete), OLAP is generally optimized for read only and might not even support other kinds of queries. OLTP also operates differently from batch processing and grid computing.Re-order buffer
A re-order buffer (ROB) is used in a Tomasulo algorithm for out-of-order instruction execution. It allows instructions to be committed in-order.
Normally, there are three stages of instructions: "Issue", "Execute", "Write Result". In Tomasulo algorithm, there is an additional stage "Commit". In this stage, the results of instructions will be stored in a register or memory. In the "Write Result" stage, the results are just put in the re-order buffer. All contents in this buffer can then be used when executing other instructions depending on these.
There are additional fields in every entry of the buffer:
Instruction type (jump, store to memory, store to register)
Destination (either memory address or register number)
Result (value that goes to destination or indication of a (un)successful jump)
Validity (does the result already exist?)Additional benefits of the re-order buffer include precise exceptions and easy rollback control of target address mispredictions (branch or jump). The ROB works by storing instructions in their original fetched order. The ROB can also be accessed from the side since each reservation station (in Tomasulo algorithm) has an additional parameter that points to instruction in the ROB. When jump prediction is not correct or a nonrecoverable exception is encountered in the instruction stream, the ROB is cleared of all instructions and reservation stations are re-initialized.Reagan Doctrine
The Reagan Doctrine was stated by Reagan in his State of the Union message on February 6, 1985: "We must not break faith with those who are risking their lives--on every continent from Afghanistan to Nicaragua--to defy Soviet-supported aggression and secure rights which have been ours from birth." It was a strategy implemented by the Reagan Administration to overwhelm the global influence of the Soviet Union in the late Cold War. The doctrine was a centerpiece of United States foreign policy from the early 1980s until the end of the Cold War in 1991.
Under the Reagan Doctrine, the United States provided overt and covert aid to anti-communist guerrillas and resistance movements in an effort to "roll back" Soviet-backed pro-communist governments in Africa, Asia, and Latin America. The doctrine was designed to diminish Soviet influence in these regions as part of the administration's overall strategy to win the Cold War.Regime change
Regime change is the replacement of one government regime with another. Use of the term dates to at least 1925. Regime change may replace all or part of the state's most critical leadership system, administrative apparatus, or bureaucracy.
It can be the deliberate product of outside force, as in warfare. Rollback is the military strategy to impose a regime change by defeating an enemy and removing its regime by force. Regime change can occur through inside change caused by revolution, coup d'état or reconstruction following the failure of a state.Rollback (data management)
In database technologies, a rollback is an operation which returns the database to some previous state. Rollbacks are important for database integrity, because they mean that the database can be restored to a clean copy even after erroneous operations are performed. They are crucial for recovering from database server crashes; by rolling back any transaction which was active at the time of the crash, the database is restored to a consistent state.
The rollback feature is usually implemented with a transaction log, but can also be implemented via multiversion concurrency control.Rollback (roller coaster)
A rollback occurs on a launched roller coaster when the train is not launched fast enough to reach the top of the tower or hill. It will roll backwards down the tower, and will be stopped by brakes on the launch track. Any roller coaster on which it is possible for a rollback to occur will have these brakes. Intamin, a manufacturer of roller-coasters, refers to the "rollback" as a "short shot".Most coasters contain at least one anti-rollback device to prevent a train from rolling backwards while ascending the main lift. This is typically with chain-driven lifts, not hydraulic launchers such as Kingda Ka or Top Thrill Dragster.STS-38
STS-38 was a Space Shuttle mission by NASA using the Space Shuttle Atlantis. It was the 37th shuttle mission, and carried a classified payload for the U.S. Department of Defense. It was the 7th flight for Atlantis and the 7th flight dedicated to the Department of Defense. The mission was a 4-day mission that traveled more than 2 million miles and completed 79 revolutions. Atlantis landed at Kennedy Space Center's Shuttle Landing Facility's runway 33. The launch was originally scheduled for July 1990, but was rescheduled due to a hydrogen leak found on Space Shuttle Columbia during the STS-35 countdown. During a rollback to the Orbiter Processing Facility Atlantis was damaged during a hail storm. The eventual launch date of 15 November 1990 was set due to a payload problem. The launch window was between 18:30 and 22:30 EST. The launch occurred at 18:48 EST.Saxbe fix
The Saxbe fix , or salary rollback, is a mechanism by which the President of the United States, in appointing a current or former member of the United States Congress whose elected term has not yet expired, can avoid the restriction of the United States Constitution's Ineligibility Clause. That clause prohibits the President from appointing a current or former member of Congress to a civil office position that was created, or to a civil office position for which the pay or benefits (collectively, "emoluments") were increased, during the term for which that member was elected until the term has expired. The rollback, first implemented by an Act of Congress in 1909, reverts the emoluments of the office to the amount they were when that member began his or her elected term.
To prevent ethical conflicts, James Madison proposed language at the Constitutional Convention that was adopted as the Ineligibility Clause after debate and modification by other Founding Fathers. Historically, a number of approaches have been taken to circumvent or adhere to the restrictions; these have included choosing another nominee, allowing the desired nominee's elected term of office to expire, ignoring the clause entirely, or reducing the offending emoluments to the level prior to when the nominee took office. Although Congress passed the mechanism reducing emoluments in 1909, the procedure was named "Saxbe fix" after Senator William Saxbe, who was confirmed as Attorney General in 1973 after Congress reduced the office's salary to the level it had been before Saxbe's term commenced. The Saxbe fix has subsequently become relevant as a successful—though not universally accepted—solution for appointments by presidents of both parties of sitting members of the United States Congress to the United States Cabinet. Members of Congress have been appointed to federal judgeships without any fix being enacted; court challenges to such appointments have failed.
There were four Saxbe fixes for appointees of presidents prior to Barack Obama. The first two rollbacks concerned appointees of Republicans William Howard Taft and Richard Nixon, and the last two were implemented for appointees of Democrats Jimmy Carter and Bill Clinton. Congress approved two more in the weeks preceding Obama's presidency in preparation for his designated Cabinet nominees. Since the 1980s, Saxbe fixes have only been temporary, extending to the conclusion of the term for which the sitting member of Congress was elected. The Clause has received relatively little scholarly or judicial attention; the sparse extant debate centers on whether the reduction of salary satisfies the Ineligibility Clause, or whether affected members of Congress are ineligible for appointment in spite of the reduction.Tow truck
A tow truck (also called a wrecker, a breakdown truck, recovery vehicle or a breakdown lorry) is a truck used to move disabled, improperly parked, impounded, or otherwise indisposed motor vehicles. This may involve recovering a vehicle damaged in an accident, returning one to a drivable surface in a mishap or inclement weather, or towing or transporting one via flatbed to a repair shop or other location.
A tow truck is distinct from a motor carrier that moves multiple new or used vehicles simultaneously in routine transport operations.Transaction processing
Transaction processing is information processing in computer science that is divided into individual, indivisible operations called transactions. Each transaction must succeed or fail as a complete unit; it can never be only partially complete.
For example, when you purchase a book from an online bookstore, you exchange money (in the form of credit) for a book. If your credit is good, a series of related operations ensures that you get the book and the bookstore gets your money. However, if a single operation in the series fails during the exchange, the entire exchange fails. You do not get the book and the bookstore does not get your money. The technology responsible for making the exchange balanced and predictable is called transaction processing. Transactions ensure that data-oriented resources are not permanently updated unless all operations within the transactional unit complete successfully. By combining a set of related operations into a unit that either completely succeeds or completely fails, one can simplify error recovery and make one's application more reliable.
Transaction processing systems consist of computer hardware and software hosting a transaction-oriented application that performs the routine transactions necessary to conduct business. Examples include systems that manage sales order entry, airline reservations, payroll, employee records, manufacturing, and shipping.
Since most, though not necessarily all, transaction processing today is interactive the term is often treated as synonymous with online transaction processing.Windows Installer
Windows Installer (previously known as Microsoft Installer, codename Darwin) is a software component and application programming interface (API) of Microsoft Windows used for the installation, maintenance, and removal of software. The installation information, and optionally the files themselves, are packaged in installation packages, loosely relational databases structured as COM Structured Storages and commonly known as "MSI files", from their default filename extensions. Windows Installer contains significant changes from its predecessor, Setup API. New features include a GUI framework and automatic generation of the uninstallation sequence. Windows Installer is positioned as an alternative to stand-alone executable installer frameworks such as older versions of InstallShield and NSIS.
Before the introduction of Windows Store, Microsoft encouraged third parties to use Windows Installer as the basis for installation frameworks, so that they synchronize correctly with other installers and keep the internal database of installed products consistent. Important features such as rollback and versioning depend on a consistent internal database for reliable operation. Furthermore, Windows Installer facilitates the principle of least privilege by performing software installations by proxy for unprivileged users.