Mollitia

Appearance

Redis ​

The Mollitia Redis addon adds redis for some modules of every circuit. The list of modules coming with redis support are Ratelimit, SlidingCountBreaker and SlidingTimeBreaker.

Quick Start ​

bash
# Install mollitia
npm install mollitia --save
# Install Redis and the Redis addon
npm install @mollitia/redis redis --save
# Install mollitia
npm install mollitia --save
# Install Redis and the Redis addon
npm install @mollitia/redis redis --save
typescript
// Then add the addon
import * as Mollitia from 'mollitia';
import { RedisAddon } from '@mollitia/redis';
// Adds the Redis addon to Mollitia
Mollitia.use(
  new RedisAddon({ 
    host: <Redis hostName>, 
    port: <Redis Port>,
    password: <Redis Password> 
  })
);
// Then add the addon
import * as Mollitia from 'mollitia';
import { RedisAddon } from '@mollitia/redis';
// Adds the Redis addon to Mollitia
Mollitia.use(
  new RedisAddon({ 
    host: <Redis hostName>, 
    port: <Redis Port>,
    password: <Redis Password> 
  })
);

Then, add redis options when creating modules. Redis is only available for Ratelimit, SlidingCountBreaker or SlidingTimeBreaker module.

typescript
const rateLimitModule = new Mollitia.Ratelimit({
  name: 'myRateLimitModule',
  limitForPeriod: 2,
  limitPeriod: 20000,
  redis: {
    // Setting redis.use to true indicates Redis should be used
    use: true
  }
};
// Creates a circuit
const myCircuit = new Mollitia.Circuit({
  // Initializes a circuit with a handler
  func: yourFunction,
  options: {
    modules: [
      rateLimit: rateLimitModule
    ]
  }
});
// This will execute yourFunction('dummy')
await myCircuit.execute('dummy');
const rateLimitModule = new Mollitia.Ratelimit({
  name: 'myRateLimitModule',
  limitForPeriod: 2,
  limitPeriod: 20000,
  redis: {
    // Setting redis.use to true indicates Redis should be used
    use: true
  }
};
// Creates a circuit
const myCircuit = new Mollitia.Circuit({
  // Initializes a circuit with a handler
  func: yourFunction,
  options: {
    modules: [
      rateLimit: rateLimitModule
    ]
  }
});
// This will execute yourFunction('dummy')
await myCircuit.execute('dummy');

API Reference ​

Options ​

When Addon is created ​

NameDescriptionDefault
getMaxDelaySpecifies the maximum time, in milliseconds,to get data from Redis500
setMaxDelaySpecifies the maximum time, in milliseconds,to set data to Redis500
ttlSpecifies the maximum duration, in milliseconds, the data stays in Redis0

At module level ​

NameDescriptionDefault
useSpecifies if the redis is used for the modulefalse
getMaxDelaySpecifies the maximum time, in milliseconds,to get data from Redis500
setMaxDelaySpecifies the maximum time, in milliseconds,to set data to Redis500
ttlSpecifies the maximum duration, in milliseconds, the data stays in Redis0

Option priority ​

When an option is defined both at Addon level and at module level, the option value is taken from module

Example:

typescript
Mollitia.use(new RedisAddon({ host: <Redis hostName>, port: <Redis Port>, password: <Redis Password>, getMaxDelay: 1000, setMaxDelay: 1000 }));
const rateLimitModule = new Mollitia.Ratelimit({
  name: 'myRateLimitModule',
  limitForPeriod: 2,
  limitPeriod: 20000,
  redis: {
    use: true,
    getMaxDelay: 500
  }
};
Mollitia.use(new RedisAddon({ host: <Redis hostName>, port: <Redis Port>, password: <Redis Password>, getMaxDelay: 1000, setMaxDelay: 1000 }));
const rateLimitModule = new Mollitia.Ratelimit({
  name: 'myRateLimitModule',
  limitForPeriod: 2,
  limitPeriod: 20000,
  redis: {
    use: true,
    getMaxDelay: 500
  }
};

With such configuration, getMaxDelay is 500, setMaxDelay is 1000 and ttl is 0 (not set, so using default value)

  • getMaxDelay and setMaxDelay

These options are available to avoid blocking the operations for a long time when Redis is slow or unavailable.

  • ttl

This option could be used to avoid keeping some keys in Redis for a long duration. Setting ttl to 0 deactivate the ttl.

Please note that this option is only applicable when Redis is used with SlidingCountBreaker module, as SlidingTimeBreaker module and Ratelimit module come with existing ttl (slidingWindowSize for SlidingCountBreaker, limitPeriod for Ratelimit).

This option is converted to a number of seconds, and rounded to the next integer.