How do I use Redis in Ruby?

First: You need to install the Redis server. Just like you would install any other database. If you’re running Ubuntu, you can use apt install redis-server , on Mac you can use brew install redis & on Windows 10 you’ll need the “Windows Subsystem for Linux” (click for instructions).

How do I start a Redis server?

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 does Redis work in Rails?

Redis is a key-value store that stands out from others, like memcached, in that it has built-in support for data structures like lists, sets, and hashes, and that it can persist data to disk. In this article, we will walk through a basic usage example in order to learn how to use Redis within a Rails application.

What is Redis gem?

Redis is an in-memory data structure store used to help building high-performance and scalable web applications, similar to Memcached, but with these main differences: Redis can store more data types besides strings, such as Hashes, Lists, Sets and Sorted Sets. I will talk about them later.

How do I use Redis cache rails?

To use Redis as a Rails cache store, use a dedicated cache instance that’s set up as an LRU (Last Recently Used) cache instead of pointing the store at your existing Redis server, to make sure entries are dropped from the store when it reaches its maximum size.

Does rails cache use Redis?

To use Redis as a Rails cache store, use a dedicated Redis cache that’s set up as a LRU (Last Recently Used) cache instead of pointing the store at your existing Redis server, to make sure entries are dropped from the store when it reaches its maximum size.

How do you bust a cache in Rails?

clear in the Rails console to clear the cache. Unfortunately there is no way (yet) to do it from the command line. We can add a rake task that will do this for us. Then we can execute ./bin/rake cache:clear and clear the Rails cache from the command line.

What does Rails cache do?

1.1 Page Caching

Page caching is a Rails mechanism which allows the request for a generated page to be fulfilled by the web server (i.e. Apache or NGINX) without having to go through the entire Rails stack. While this is super fast it can’t be applied to every situation (such as pages that need authentication).

Where is Rails cache stored?

2) ActiveSupport::Cache::FileStore: Cached data is stored on the disk. This is the default store and the default path for this store is: /tmp/cache. Works well for all types of environments and allows all processes running from the same application directory to access the cached content.

Does ActiveRecord cache?

ActiveRecord makes accessing your database easy, but it can also help make it faster by its intelligent use of caching.

What is the reason for using concerns in rails?

Using Concerns to make the classes smaller

In those situations, when a file exceeds a particular threshold, the quickest solution is to extract a concern. The logic is moved elsewhere and the number of lines of that class is reduced.

What is Mixins in rails?

A mixin can basically be thought of as a set of code that can be added to one or more classes to add additional capabilities without using inheritance. In Ruby, a mixin is code wrapped up in a module that a class can include or extend (more on those terms later). In fact, a single class can have many mixins.

How do I create a concern in rails?

Using extend ActiveSupport::Concern tells Rails that we are creating a concern.

Do the following:

  1. Generate your Twit model: rails g model Twit tweet:text .
  2. Generate your TwitsController: rails g controller TwitsController .
  3. Navigate to app/controllers/concerns and create the file twitable. rb, pasting in the following:

What are concerns for rails?

According to the Rails docs, we want to encapsulate the code in a different module to reuse that code in different places when that same functionality is needed. We use concerns when we feel that one file is overwhelmed with the functionality, so we extract some part of the code and save it into another file or module.

What are services in Rails?

A service object in Rails is a plain old Ruby object created for a specific business action. It usually contains code that doesn’t fit in the model or view layer, e.g., actions via a third-party API like posting a tweet.

What are ActiveSupport concerns?

ActiveSupport::Concern provides the mechanics to encapsulate a cohesive chunk of functionality into a mixin that can extend the behavior of the target class by annotating the class’ ancestor chain, annotating the class’ singleton class’ ancestor chain, and directly manipulating the target class through the included()

What is delegate in Ruby on Rails?

delegate provides a delegate class method to easily expose contained objects’ public methods as your own. You can set one or more method names (specified as symbols or strings) if you want. And the name of the target object via the :to option(also a symbol or string).

What is delegate method?

A delegate method is a method that the delegate object is expected to implement. Some delegate methods are required, while some are not. In IOS, most delegates are expected to conform to an Objective-C protocol; the protocol declaration will tell you which methods are optional and which are required.

How do I invoke a delegate?

Delegates can be invoke like a normal function or Invoke() method. Multiple methods can be assigned to the delegate using “+” or “+=” operator and removed using “-” or “-=” operator. It is called multicast delegate. If a multicast delegate returns a value then it returns the value from the last assigned target method.