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What is the difference between asynchronous and synchronous execution?

When you execute something synchronously, you wait for it to finish before moving on to another task. When you execute something asynchronously, you can move on to another task before it finishes. That being said, in the context of computers this translates into executing a process or task on another "thread." A thread is a series of commands (a block of code) that exists as a unit of work. The operating system can manage multiple threads and assign a thread a piece ("slice") of processor time before switching to another thread to give it a turn to do some work. At its core (pardon the pun), a processor can simply execute a command, it has no concept of doing two things at one time. The operating system simulates this by allocating slices of time to different threads. Now, if you introduce multiple cores/processors into the mix, then things CAN actually happen at the same time. The operating system can allocate time to one thread on the first processor, then a

The Complete Guide to Creating Symbolic Links (aka Symlinks) on Windows

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Windows 10, 8, 7, and Vista all support symbolic links—also known as symlinks—that point to a file or folder on your system. You can create them using the Command Prompt or a third-party tool called Link Shell Extension. What Are Symbolic Links? Symbolic links are basically advanced shortcuts. Create a symbolic link to an individual file or folder, and that link will appear to be the same as the file or folder to Windows—even though it’s just a link pointing at the file or folder. For example, let’s say you have a program that needs its files at C:\Program. You’d really like to store this directory at D:\Stuff, but the program  requires  that its files be at C:\Program. You could move the original directory from C:\Program to D:\Stuff, and then create a symbolic link at C:\Program pointing to D:\Stuff. When you relaunch the program, it will try to access its directory at C:\Program. Windows will automatically redirect it to D:\Stuff, and everything will just work as if it

Multi-Factor Authentication

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AWS Multi-Factor Authentication (MFA) is a simple best practice that adds an extra layer of protection on top of your user name and password. With MFA enabled, when a user signs in to an AWS website, they will be prompted for their user name and password (the first factor—what they know), as well as for an authentication code from their AWS MFA device (the second factor—what they have). Taken together, these multiple factors provide increased security for your AWS account settings and resources. You can enable MFA for your AWS account and for individual IAM users you have created under your account. MFA can be also be used to control access to AWS service APIs. After you've obtained a supported hardware or virtual MFA device, AWS does not charge any additional fees for using MFA. You can also protect  cross-account access using MFA . MFA Form Factors   Virtual MFA Device Hardware Key Fob MFA Device Hardware Display Card MFA Device SMS MFA Dev

How to Change Mobile Number in AADHAAR Card without OTP

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How to Change Mobile Number in AADHAAR Card without OTP Many people face the problem of linking the mobile number with AADHAAR card. It is required during the e-verification of Income Tax Return and several other purposes. The government of India(GOI) is continuously pushing AADHAAR to a large extent and it will become important for accessing the various benefits from the government. Hence, it is really necessary to update the AADHAAR database with all your latest and relevant details including phone number. Suppose, you have lost your phone or the old number is not working due to some reason, you need to change the mobile number in AADHAAR database as well. Read the below article to know how to change mobile number in AADHAAR card without OTP. Why is the mobile number required to be updated in AADHAAR database? Recently Income Tax Department has launched a drive to link the AADHAAR number with PAN. You can do the same easily by visiting the income tax e-filling webs

Knowing about the expiry date of Gas Cylinder

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LPG gas is the most used cooking fuel in India and many other countries. Not only does it make your mother's kitchen work convenient, it is also a live bomb sitting just next to her almost all the time. Did you know that there is an expiry date (physical life) for LPG cylinders? Expired Cylinders are not safe for use and can cause lethal accidents. Using LPG cylinder post its expiry date can result in leakage that can also lead to an explosion. Once the cylinder is past the expiry date, one must stop using it. But most people have no idea how to check the expiry of the bottle. The steps to check the expiry are very simple and basic. Here is how you can check the expiry date of LPG cylinders : On one of three side stems of the cylinder, the expiry date is coded alpha numerically which starts with  A, B, C or D  followed by a  two digit number . e.g. D-06. The expiry of LPG Cylinder can be found on one of the metal strips that connect the body of the cylinder to top ring (h

What is the difference between Custom tag and Coldfusion Component?

The differences are Custom Tags: -A single entry point is available for custom tags -Custom tags does not support formalized parameter passing and validation mechanism -Persistence is not possible for custom tags -Custom tags are accessible locally and only by ColdFusion ColdFusion Component: -Multiple entry points are available for CFC -CFC does support formalized parameter passing and validation mechanism -Persistence is possible for CFC -CFCs can be accessed as web services

How to I initialize a CFC at the same time as I create it?

In many examples using CFCs, the call that creates the CFC also calls an init() method. This is done to both create an instance of a CFC as well as initialize it with certain information. So for example, you may want to pass in a datasource name to a CFC so that the component can perform database queries. How is this done? This is a 2 step process. The first is to call the CFC using syntax like the example below: <cfset cachedQuery = createObject("component", "CachedQuery").init(dsn)> This says to create a variable called cachedQuery which will contain a reference to a CFC. The CFC is created using the createObject() function. At the same time that the CFC is created, a method of the CFC called init() is called. Whatever is returned from the init() method is what will actually be loaded into the CachedQuery variable. This is called method chaning. It is essentially the act of calling multiple functions in one line. The result of the first operation (cre