What is speculative execution in computer architecture?
Speculative execution is an optimization technique where a computer system performs some task that may not be needed. Work is done before it is known whether it is actually needed, so as to prevent a delay that would have to be incurred by doing the work after it is known that it is needed.
Which of the following allows speculative execution?
8. Which of the following allows speculative execution ? Explanation: The direct mapped cache has the advantage of allowing a simple and fast speculative execution .
What is speculative execution in Hadoop?
In Hadoop , Speculative Execution is a process that takes place during the slower execution of a task at a node. In this process, the master node starts executing another instance of that same task on the other node. And the task which is finished first is accepted and the execution of other is stopped by killing that.
What is speculative data?
Speculation (also known as speculative loading ), is a process implemented in Explicitly Parallel Instruction Computing ( EPIC ) processors and their compiler s to reduce processor-memory exchanging bottlenecks or latency by putting all the data into memory in advance of an actual load instruction.
Has out of order execution?
In computer engineering, out-of-order execution , OoOE, is a technique used in most high-performance microprocessors to make use of cycles that would otherwise be wasted by a certain type of costly delay. Most modern CPU designs include support for out of order execution .
What is speculative execution in Hadoop Why is it important?
The goal of Speculative execution is reducing the execution time, but not at the cost of cluster efficiency. In a Busy Cluster, this will result in reducing the overall throughout. speculative execution is a feature in Hadoop when the hadoop framework starts to clone the “long running” task in another node.
What cache memory is?
Cache is a small amount of memory which is a part of the CPU – closer to the CPU than RAM . It is used to temporarily hold instructions and data that the CPU is likely to reuse.
What is the high speed memory between the main memory and the CPU called?
How is memory accessed in RISC architecture?
Memory Access is accomplished through Load and Store instructions only, thus the term “Load/Store Architecture ” is often used when referring to RISC . The RISC pipeline is specified in a way in which it must accommodate both: operation and memory access with equal efficiency.
What is yarn Hadoop?
YARN is an Apache Hadoop technology and stands for Yet Another Resource Negotiator. The technology is designed for cluster management and is one of the key features in the second generation of Hadoop , the Apache Software Foundation’s open source distributed processing framework.
What is Hadoop Streaming?
Hadoop streaming is a utility that comes with the Hadoop distribution. This utility allows you to create and run Map/Reduce jobs with any executable or script as the mapper and/or the reducer.
What is speculative execution in MapReduce?
Speculative execution in Hadoop MapReduce is an option to run a duplicate map or reduce task for the same input data on an alternative node. This is done so that any slow running task doesn’t slow down the whole job.
What is the need for speculation?
Description: Speculators are prevalent in the markets where price movements of securities are highly frequent and volatile. They play very important roles in the markets by absorbing excess risk and providing much needed liquidity in the market by buying and selling when other investors don’t participate.
What is Spectre mitigation?
spectreattack.com. Spectre is a vulnerability that affects modern microprocessors that perform branch prediction. On most processors, the speculative execution resulting from a branch misprediction may leave observable side effects that may reveal private data to attackers.
How is hardware speculation done?
Hardware -based speculation follows the predicted flow of data values to choose when to execute instructions. The key idea behind implementing speculation is to allow instructions to execute out of order but to force them to commit in order and to prevent any irrevocable action until an instruction commits.