what is the redis server

What is Redis and why is it so popular?

The Redis implementation makes heavy use of the fork system call, to duplicate the process holding the data, so that the parent process continues to serve clients, while the child process creates a copy of the data on disk. According to monthly DB-Engines rankings, Redis is often the most popular key–value database.

How to install and setup Redis?

* Redis Quick Start

• * Installing Redis. The suggested way of installing Redis is compiling it from sources as Redis has no dependencies other than a working GCC compiler and libc.
• * Starting Redis. ...
• * Check if Redis is working. ...
• * Securing Redis. ...
• * Using Redis from your application. ...
• * Redis persistence. ...
• * Installing Redis more properly. ...

What is Redis and what is it used for?

What is Redis? Redis (which stands for REmote DIctionary Server) is an open-source in-memory data structure store that is commonly used to implement non-relational key-value databases and caches. This distinction is important: Redis is technically a data structure store, and not a key-value database.

How to keep Redis server running?

• Download either .msi or .zip file, this tutorial will let you download latest zip file. Redis-x64-3.2.
• Extract the zip file to prepared directory.
• Run redis-server.exe, you can either directly run redis-server.exe by clicking or run via command prompt.
• Run redis-cli.exe, after successfully running the redis-server.

What is Redis server and how it works?

Redis is an open-source, highly replicated, performant, non-relational kind of database and caching server. It works by mapping keys to values with a sort of predefined data model. Its benefits include: Mapped key-value-based caching system, almost comparable to memcached.

Is Redis a database or a cache?

Everyone knows Redis began as a caching database, but it has since evolved into a primary database. Many applications built today use Redis as a primary database. However, most Redis service providers support Redis as a cache but not as a primary database.

Does Redis need a server?

You're not required to host Redis on a separate server at all. In fact, it's not uncommon for application servers to run an in-memory store like Redis or Memcached on the same server for simple caching tasks.

Where is Redis server?

The Redis configuration file is located at installdir/redis/etc/redis.

Why do I need Redis?

Redis enables you to write traditionally complex code with fewer, simpler lines. With Redis, you write fewer lines of code to store, access, and use data in your applications. The difference is that developers who use Redis can use a simple command structure as opposed to the query languages of traditional databases.

What is Redis in simple words?

Redis is an open source (BSD licensed), in-memory data structure store used as a database, cache, message broker, and streaming engine. Redis provides data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, geospatial indexes, and streams.

Is Redis SQL?

Redis is a data structure store that can be used as a database, cache, or even a message broker. The storage structure is both open-source and in-memory. It is also NoSQL-based. This means it allows data structures like strings, hashes, lists, sets, sorted sets of data, bit maps, and so on.

How is data stored in Redis?

Since Redis is an in-memory database, data is stored in memory (or RAM). If a server crashes, all the data stored is lost. Redis has back-up mechanisms in place for the data on the disk. This way, the data is loaded from the disk to the memory when the server reboots.

What kind of database is Redis?

Redis is a type of database that's commonly referred to as No SQL or non-relational . In Redis, there are no tables, and there's no database-defined or -enforced way of relating data in Redis with other data in Redis.

Can I run Redis locally?

To start Redis client, open the terminal and type the command redis-cli. This will connect to your local server and now you can run any command. In the above example, we connect to Redis server running on the local machine and execute a command PING, that checks whether the server is running or not.

How do I connect to a Redis server?

To connect to your Redis server remotely, you first need to open the appropriate port in your firewall and bind Redis to an address.Open port 6379 on your system's firewall. ... Open the redis. ... Once you have these configurations set up on the server, you can connect to Redis from a remote client.

How do I know if Redis is running?

you can do it by this way. $redis = new Redis(); $redis->connect('127.0. 0.1', 6379); echo $redis->ping(); and then check if it print +PONG , which show redis-server is running.

Can we use Redis as database?

Redis can be used as a distributed cache, which is probably its most common and popular use case, as a NoSQL Database and as a Message broker (pub\sub mode, similar to Kafka or RabbitMQ).

Is cache a database?

A database cache supplements your primary database by removing unnecessary pressure on it, typically in the form of frequently accessed read data. The cache itself can live in a number of areas including your database, application or as a standalone layer.

What kind of database is Redis?

Redis is a type of database that's commonly referred to as No SQL or non-relational . In Redis, there are no tables, and there's no database-defined or -enforced way of relating data in Redis with other data in Redis.

Can Redis be used as primary database?

Of course when using Redis as a primary database you don't need an additional cache, because you have that automatically out of the box with Redis. That means again less complexity in your application, because you don't need to implement the logic for managing populating and invalidating cache.

What is the Redis server?

The name Redis means REmote DIctionary Server. The Redis project began when Salvatore Sanfilippo, nicknamed antirez, the original developer of Redis, was trying to improve the scalability of his Italian startup, developing a real-time web log analyzer.

What is a redis?

Redis ( / ˈrɛdɪs /; Remote Dictionary Server) is an in-memory data structure store, used as a distributed, in-memory key–value database, cache and message broker, with optional durability.

What is the difference between Redis and other structured storage systems?

An important difference between Redis and other structured storage systems is that Redis supports not only strings, but also abstract data types:

How does Redis work?

Persistence in Redis can be achieved through two different methods. First by snapshotting, where the dataset is asynchronously transferred from memory to disk at regular intervals as a binary dump, using the Redis RDB Dump File Format. Alternatively by journaling, where a record of each operation that modifies the dataset is added to an append -only file (AOF) in a background process. Redis can rewrite the append-only file in the background to avoid an indefinite growth of the journal. Journaling was introduced in version 1.1 and is generally considered the safer approach.

What is Redis database?

Redis ( / ˈrɛdɪs /; Remote Dictionary Server) is an in-memory data structure store, used as a distributed, in-memory key–value database, cache and message broker, with optional durability. Redis supports different kinds of abstract data structures, such as strings, lists, maps, sets, sorted sets, HyperLogLogs, bitmaps, streams, and spatial indices. The project was developed and maintained by Salvatore Sanfilippo. From 2015 until 2020, he led a project core team sponsored by Redis Labs. Salvatore Sanfilllippo left Redis as the maintainer in 2020. It is open-source software released under a BSD 3-clause license. In 2021, not long after the original author and main maintainer left, redisLabs dropped the Labs from its name and now redis, the open source DB as well as redisLabs, the commercial company, are referred to as "redis".

Why does Redis rewrite append only?

Redis can rewrite the append-only file in the background to avoid an indefinite growth of the journal. Journaling was introduced in version 1.1 and is generally considered the safer approach. By default, Redis writes data to a file system at least every 2 seconds, with more or less robust options available if needed.

How often does Redis write to a file system?

By default, Redis writes data to a file system at least every 2 seconds, with more or less robust options available if needed. In the case of a complete system failure on default settings, only a few seconds of data would be lost.

What is Redis?

Redis, which stands for Remote Dictionary Server, is a fast, open source, in-memory, key-value data store. The project started when Salvatore Sanfilippo, the original developer of Redis, wanted to improve the scalability of his Italian startup. From there, he developed Redis, which is now used as a database, cache, message broker, and queue.

Benefits of Redis

All Redis data resides in memory, which enables low latency and high throughput data access. Unlike traditional databases, In-memory data stores don’t require a trip to disk, reducing engine latency to microseconds. Because of this, in-memory data stores can support an order of magnitude more operations and faster response times.

Popular Redis Use Cases

Redis is a great choice for implementing a highly available in-memory cache to decrease data access latency, increase throughput, and ease the load off your relational or NoSQL database and application.

Redis vs. Memcached

Both Redis and Memcached are in-memory, open-source data stores. Memcached, a high-performance distributed memory cache service, is designed for simplicity while Redis offers a rich set of features that make it effective for a wide range of use cases. For more detailed feature comparison to help you make a decision, view Redis vs Memcached .

Using Redis on AWS

AWS offers two fully managed services compatible with Redis: Amazon MemoryDB for Redis and Amazon ElastiCache for Redis.

Try it

Ready for a test drive? Check this interactive tutorial that will walk you through the most important features of Redis.

Download it

Redis 6.2.6 is the latest stable version. Interested in release candidates or unstable versions? Check the downloads page.

Quick links

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Who uses Redis?

Companies: 5000+ companies reportedly use Redis in their tech stacks, including Snapchat, Twitter, Slack, Uber, Airbnb, and Pinterest.

What is Redis used for?

According to Redis official doc, Redis is an open-source (BSD licensed), in-memory data structure store, used as a database, cache, and message broker.

Why Redis?

It supports caching. Caching is the process of storing some data in Cache. Cache is a temporary storage component area where the temporary data is stored so that in the future, data can be served faster. For that case, Redis is used.

What should clients know about Redis cluster?

Clients connecting to the Redis cluster should be aware of the cluster topology, causing overhead configuration on Clients.

How big is Redis?

Redis allows storing key and value pairs as large as 512 MB.

Is Redis hard to go deep?

There are many more pros of Redis. going deep is very hard at this time.

Is Redis classy?

In short, Redis is classy. Give it a try.

Overview

Data types

Redis maps keys to types of values. An important difference between Redis and other structured storage systems is that Redis supports not only strings, but also abstract data types:
• Lists of strings
• Sets of strings (collections of non-repeating unsorted elements)
• Sorted sets of strings (collections of non-repeating elements ordered by a floating-point number called score)

History

Differences from other database systems

Popularity

Supported languages

Persistence

Replication