volos-quota-redis

Redis provider for Quota enforcement in the Volos system.

volos-quota-redis

This is a Redis-backed implementation of quota support for Volos.

Once initialized, the interface to the module is exactly what is in the "volos-quota-common" module. See that module for detailed docs.

To initialize a quota, you call "create" on the exported module and pass a single "options" object. It can contain the following parameters:

  • timeUnit: How often the quota resets -- may be minute, hour, day, week, or month
  • interval: Works with the timeUnit to determine how often the quota resets. For instance, every 5 days or 2 weeks.
  • startTime: A time at which the quota calculations should begin. For instance, if there is no start time then a quota set to reset in "one day" will reset 24 hours after the first message is receiver, but if the start time is set to the top of the hour on some day, then the quota will always reset at the top of the hour. Start time is not allowed for "month" timeUnit as it always uses Gregorian month boundaries.
  • allow: The maximum number of requests to allow. This may be overridden on each "apply" call if desired.
  • host: Host where your Redis instance is running - defaults to 127.0.0.1
  • port: Port of the Redis instance - defaults to 6379.
  • db: Redis DB to use - defaults to 0.

Once the quota has been initialized, the module that is returned has the programming interface defined by the "volos-quota-common" module.

var quotaModule = require('volos-quota-redis');
var quota = quotaModule.create({
  timeUnit: 'day',
  interval: 1,
  allow: 10
  });
 
quota.apply({ identifier: 'Foo', weight: 1 }, function(errresult) {
  if (err) {
    throw err;
  } else {
    console.log('Quota status: %s', result.isAllowed);
  }
});