Refresh Azure Redis Cache every 15 minutes - mysql

Question

I need to sync data from MySQL Database to Redis Cache every 15 minutes so that cache as latest data.
I am using ubuntu for hosting (Node.js) webservcies. So everytime there is call for rest api it needs to fetch data from cache and serve it.
So now do I need write a background job to sync MySQL data to Cache memory.
If I need to write a background job can I write In node.js and sync it and run as a background job in Ubuntu using crontab command.

Answer 1

Yes. You can write a nodejs script and run it thru crontab command to sync data from MySQL to Redis.
Per my experience, you need some nodejs packages below to help implement the needs.
NodeJS ORM for MySQL:
Sequelize: http://docs.sequelizejs.com/en/latest/ (npm install
sequelize mysql)
Redis Client for NodeJS:
ioredis: https://github.com/luin/ioredis (npm install ioredis)
node_redis: https://github.com/NodeRedis/node_redis (npm install
redis)
The sample code ~/sync-mysql-redis.js:
// Create a mysql client connection
var Sequelize = require('sequelize');
var sequelize = new Sequelize('mysql://user:pass#azure_mysql_host:3306/dbname');
// Create a redis client using node_redis
var redis = require("redis");
var client = redis.createClient(6379, '<redis_host>');
// Query entities data from MySQL table
sequelize.query("SELECT * FROM `t_entity`", { type: sequelize.QueryTypes.SELECT})
.then(function(entities) {
for(var entity in entites) { // for-each entity from entites list
var hash_key = entity.Id // for example, get the entity id as redis hash
for(var prop in entity) { // for-each property from entity
client.hset([hash_key, prop, entity[prop]], redis.print); // mapping a mysql table record to a redis hash
}
}
});
For crontab configuration, you need to vim /etc/crontab as root or sudo user:
$ sudo vim /etc/crontab
# Add a crontab record to run nodejs script interval 15 mins
*/15 * * * * node \home\user\sync-mysql-redis.js