#Nodejs cache install#
#Nodejs cache update#
#Nodejs cache password#

Next up we will add a very slim Redis wrapper to talk to redis where the credentials will be placed in the config.js file under the redis attribute as follows: redis : ) In my case it installed the redis npm package version 3.1.2.

#Nodejs cache install#

To add Redis to the Node.js Express Quotes API, we will first add the redis npm library with: npm install -save redis

Add Redis to the Node.js Express Quotes API # For reference, I created a database with the following configuration.

#Nodejs cache password#

From there get the Redis host, port, and password you can use later in this tutorial. We will be using a free Redis database on RedisLabs, please get your $0 Redis up and running following this guide. It is highly recommended you clone the Quotes API Github repository and start from the master branch to follow along. We will add a new endpoing and caching layer where we will cache the JSON on Redis hosted on Redis Labs. It has a simple endpoint /quotes that gets a list of quotes from the database and renders it as JSON. We will use an existing quotes API application built with Node.js and Postgres database. Given the prerequisites are done, let’s go to what we will be building. You should read the Node.js Postgres tutorial that explains how the quotes API is built.An account on Redis Lab will be required, you can get your free account with a 30 MB Redis.Having an understanding of Javascript callback, promise and Async await will be really helpful.A basic understanding of how Redis works and its general commands are expected.You have an understanding of how HTTP generally functions.You are aware of how Node.js and Express js works.Add Redis to the Node.js Express Quotes APIīefore we dive into the demo application and its code, below are some of the things better to know:.In this post, we will see how we can do this by adding a Redis cache to an existing Node.js API that uses the Postgres database. The caching store needs to provide the ttl method.HTTP responses can be sped up with Node.js and Redis caching.The background refresh mechanism currently does not support providing multiple keys to wrap function.If the threshold is low and the worker function is slow, the key may expire and you may encounter a racing condition with updating values.

In case of multicaching, the store that will be checked for refresh is the one where the key will be found first (highest priority).

The value will then be set in all the stores. In case of multicaching, the store that will be used for refresh is the one where the key will be found first (highest priority).

In the meantime, the system will return the old value until expiration.

#Nodejs cache update#

If the remaining TTL is less than refreshThreshold, the system will spawn a background worker to update the value, following same rules as standard fetching. If refreshThreshold is set and if the ttl method is available for the used store, after retrieving a value from cache TTL will be checked. This is done by adding a refreshThreshold attribute while creating the caching store. Set(key, val, ) Refresh cache keys in backgroundīoth the caching and multicaching modules support a mechanism to refresh expiring cache keys in background when using wrap function.