Technology Questions

virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2). LAN is the abbreviation for local area network and in this context, virtual refers to a physical object recreated and altered by additional logic.

VLANs work by applying tags to network packets and handling these tags in networking systems – creating the appearance and functionality of network traffic that is physically on a single network but acts as if it is split between separate networks. In this way, VLANs can keep network applications separate despite being connected to the same physical network, and without requiring multiple sets of cabling and networking devices to be deployed.

Contextual selector addresses specific occurrence of an element.
It is a string of individual selectors separated by white space (search pattern), where only the last element in the pattern is addressed providing it matches the specified contex.

JavaScript is a scripting language most often used for client-side web development.

- Scheduling and executing the batch jobs.

- Configuring, starting and stopping the real-time services

- Adapters configuration and managing them.

- Repository usage, Job Server configuration.

- Access Server configuration.

- Batch job publishing.

- Real-time services publishing through web services.

The mapreduce framework contains most of the key architecture principles of cloud computing such as:

- Scale: The framework is able to expand itself in direct proportion to the number of machines available.

- Reliable: The framework is able to compensate for a lost node and restart the task on a different node.

- Affordable: A user can start small and over time can add more hardware.

Copy() makes a copy of the file. It returns TRUE on success. It can copy from any source to destination. Move simply Moves the file to destination if the file is valid. While move can move the uploaded file from temp server location to any destination on the server. If filename is a valid upload file, but cannot be moved for some reason, no action will occur.

- localStorage object stores the data without an expiry date while sessionStorage object stores the data only for one session. 

- With localStorage object, data will not be deleted when the browser window is closed while the data is deleted when the browser window closes with sessionStorage objects.

A static variable in Java belongs to its class and its value remains the same for all its instances. A static variable is initialized when the class is loaded by the JVM. If your code tries to access a non-static variable, without any instance, the compiler will complain, because those variables are not created yet and they are not associated with any instance.