All posts by Pramod T P

Redis

Redis is a data structure server. It is open-source, networked, in-memory, and stores keys with optional durability.

Redis is an open source, BSD licensed, advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.

Varnish

Varnish is an HTTP accelerator designed for content-heavy dynamic web sites as well as heavily consumed APIs.

Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 – 1000x, depending on your architecture.

Varnish stores data in virtual memory and leaves the task of deciding what is stored in memory and what gets paged out to disk to the operating system. This helps avoid the situation where the operating system starts caching data while it is moved to disk by the application.

Furthermore, Varnish is heavily threaded, with each client connection being handled by a separate worker thread. When the configured limit on the number of active worker threads is reached, incoming connections are placed in an overflow queue; when this queue reaches its configured limit incoming connections will be rejected.

Write a statement to show the joining of multiple comparisons in PHP?

PHP allows multiple comparisons to be grouped together to determine the condition of the statement. It can be done by using the following syntax:
comparison1 and|or|xor comparison2 and|or|xor comparison3 and|or|xor.
The operators that are used with comparisons are as follows:
1. and: result in positive when both comparisons are true.
2. or: result in positive when one of the comparisons or both of the comparisons are true.
3. xor: result in positive when one of the comparisons is true but not both of the comparisons.