haraka-nosql

haraka-nosql

Store stuff in memory-backed objects, smartly.

Usage

var NoSQL = require('haraka-nosql');
var nosql = new NoSQL('myindex', {
    storage: 'redis',  // or 'ram' or 'ssc'
    expire: 10,        // minutes
});

Exports the following functions:

set

nosql.set('foo', 'bar', function (err, result) {
    if (err) {
        // error handling code
        return;
    }
    // do fun stuff with result
});

You're confident it'll work out? Skip the callback, it's optional. For all of these methods.

nosql.set('foo', 'bar');  // going commando

get

nosql.get('foo', function (err, result) {
    if (err) { return; }
    // result == 'bar'  (because that's what we set it to)
});

del

nosql.del('foo', function (err, result) {
    if (err) { return; }
    // result == 1   (# of objects keys deleted)
});

incrby

nosql.incrby('my_counter', 1, function (err, result) {
    if (err) { return; }
    // result == 1  (it was undef, now it's initialized to 1)
});

nosql.incrby('my_counter', 2);  // breezy!
// now my_counter == 3   (increment 1 with 2 and math!)

reset

nosql.reset();

// all your keys are belong to /dev/null

RAM? That ain't workin'

Pros

• simple
• no dependencies

Cons

• Data disappears when Haraka is restarted.
• Not shared across hosts
• With cluster, worker processes share no data. Therefore, each worker process has a partial (incomplete) view of the state data.

Cluster RAM

• When running with cluster, nosql attempts to load strong-store-cluster, which stores data in the master worker.

Pros

• All Haraka processes share a single RAM backed data store.

Cons

• There's no "reset" operation. Instead, keys expire after 10 minutes (edit config/nosql.ini [cluster]expire to alter. This is great for features such as concurrency or brute-force auth tracking.

Redis

Pros

• disk backed RAM storage
• same view across Harka master & worker processes
• persistence across Haraka & server reboots
• network service, can be shared by many hosts

Enable Redis

sed -i.bak -e 's/; backend=redis/backend=redis/' /my/haraka/config/nosql.ini

Redis isn't running on localhost!

$EDITOR config/nosql.ini

Edit the settings in the [redis] section.

I need more Redis features

When Redis is configured, the redis connection is exported as nosql.redis. Use it like so:

var nosql = require('haraka-nosql');
var redis = nosql.redis;

redis.multi()
     .hget('something')
     .get('else')
     .exec(function (err, res) {
     });

Refer to the excellent Redis command docs

Other

What about key collisions?

Collisions are only possible within your namespace. Each caller of nosql automatically gets its own namespace. In RAM, each namespace is a JS object, rather like this:

{
    karma: {
        key: val,
        key2: val2,
    },
    limit: {
        key: val,
        key2: val2,
    }
}

In Strong Store Cluster, each caller gets its own collection.

In Redis, get|del|incrby operations are mapped to their hash equivalents (hget, hdel, hincrby).