Jeeng-configs-cache

This is a helper package for Jeeng application LTD. It's main purpose is to support serverless architecture solutions. Mainly a quick way to efficiently store state and/or config values across serverless function invokations. It uses a Redis database and a postgres database for failover.

It searches the requested value in the following manner:

1. Search the Redis database for the value (Search for key: <keyPrefix>-valueName)
2. If found:
   1. Respond with found value
3. else:
   1. Search postgres database (Search table valuesTable).
   2. If not found:
      1. Respond with null
   3. Else:
      1. Store value in redis (in key: <keyPrefix>-valueName) with TTL of ttl seconds.
      2. Response with found value

Install

npm install --save jeeng-configs-cache

Usage

1. Import package: const ConfigsCache = require('jeeng-configs-cache')

2. Instanciate a ConfigCache object: const configCache = new ConfigCache(<POSTGRES_CONNECTION_STRING>, <REDIS_CONNECTION_OBJECT>, options)

Where:

• POSTGRES_CONNECTION_STRING - is a postgres connection string of the format: postgres://<user>:<password>@<host>:<port>/<database>
• REDIS_CONNECTION_OBJECT is an object with connection params as specified in the package promise-redis

3. Start retrieving values efficiently: const someValue = configCache.get('someValue')

Options

| option | default value | description | |-------------|------------------|-------------| | keyPrefix | jeengConfigCache | The prefix for stored keys in Redis database. | | valuesTable | configs | Table name where values are stored in postgres database.Table is of the following structure:|id::serial | name::varchar | value::varchar | optional more columns|| | ttl | 3600 | The TTL of stored values in the Redis database |