WITH MONGODB

FAST REST APIS DEVELOPMENT

Pablo Enfedaque Vidal @pablitoev56

WHO? •  Pablo Enfedaque

•  Computers Engineer

•  Tech Lead and R&D software engineer at Telefonica Digital

•  Working with MongoDB for some years.

TELEFONICA DIGITAL. WHAT? •  Telefonica

•  Fifth largest telecommunications company in the world

•  Operations in Europe (7 countries), the United States and Latin America (15 countries)

•  Movistar, O2, Vivo, Terra, Tuenti, Jahjah, Tokbox, everything.me, Open Web Device…

TELEFONICA DIGITAL. WHAT? •  Telefonica Digital

•  Web and mobile digital contents and services division

•  Product Development and Innovation unit

•  Products & services development, research, technology strategy, user experience, deployment & operations…

•  Around 70 different on going projects

OUR PROJECTS •  Full product development, with life cycle and several deployments

•  20 people team, 1 year or more

•  Pilot or small product to be deployed in a certain environment •  6 people team, 6 months

•  Seedbed or proof of concept to be run with reduced set of users •  3 people team, 3 months

•  Ten Fridays open exploratory project to work on your ideas •  2 people team, 10 days (consecutive Fridays)

SO…

FAST DEVELOPMENT IS REALLY CRUCIAL FOR US

HOW TO SPEED UP OUR DEVELOPMENTS? •  Agile methodologies

•  Lean startup

•  eXtreme Programming

•  Continuous Integration

•  …

HOW TO SPEED UP OUR DEVELOPMENTS?

CHOOSE THE

RIGHT TECHNOLOGY (AT FIRST)

¿ RIGHT TECHNOLOGY ?

THE RIGHT TECHNOLOGY •  Faster development with Dynamic Languages

•  3x

•  4x

•  10x

THE RIGHT TECHNOLOGY

THE SAME CAN BE STATED FOR MONGODB •  3x

•  4x

•  10x

THE RIGHT TECHNOLOGY •  Several times faster development with Dynamic Languages

•  Several times faster development with MongoDB

AND BOTH TOGETHER IS A WIN WIN

WHY? HOW?

LET’S SEE SOME EXAMPLES

ONLY DYNAMIC LANGUAGES?

JAVA VERSION public int[] getDims() {

if (this.dims != null) { return this.dims;}BasicDBObject query = new BasicDBObject();query.put("_id", "ctxt_dimensions");DBObject setup = setup_coll.findOne(query);BasicDBList dbl = (BasicDBList)setup.get("dims");this.dims = new int[dbl.size() + 2];BasicDBObject users_counter_ref = new BasicDBObject("_id", users_coll_name);BasicDBObject apps_counter_ref = new BasicDBObject("_id", apps_coll_name);dims[0] = (Integer)counters_coll.findOne(users_counter_ref).get("value") + 1;dims[1] = (Integer)counters_coll.findOne(apps_counter_ref).get("value") + 1;for (int i=0; i<dbl.size(); i++) { dims[i + 2] = (Integer)dbl.get(i); }return dims;

}

PYTHON VERSION def get_dims(self): ud = self.counters_coll.find_one({'_id': 'users'})['value'] ad = self.counters_coll.find_one({'_id': 'applications'})['value'] res = [ud, ad] res.extend(self.setup_coll.find_one({}, {'dims': 1})['dims']) return res

IT’S UP TO YOU…

THE RIGHT TECHNOLOGY

LET’S PLAY TO SPOT THE

DIFFERENCES

EXAMPLE: SPEAKER JSON {

"name": "Pablo Enfedaque",

"company": "Telefonica Digital",

"accepted": true,

"registration_date": "2012-03-15T14:35:05",

"num_talks": 1,

”votes": 4,

"email": "pev@td.com"

}

EXAMPLE: DECODED JSON (PYTHON) {

"name": "Pablo Enfedaque",

"company": "Telefonica Digital",

"accepted": True,

"registration_date": datetime(2012, 3, 15, 14, 35, 5),

"num_talks": 1,

”votes": 4,

"email": "pev@td.com"

}

EXAMPLE: MONGODB BSON {

"name": "Pablo Enfedaque",

"company": "Telefonica Digital",

"accepted": true,

"registration_date": ISODate("2012-03-15T14:35:05Z"),

"num_talks": 1,

”votes": 4,

"email": "pev@td.com",

”_id": ObjectId("5142d08c5db1362abc2d208b”)

}

LOOKS PRETTY

STRAIGHT FORWARD, RIGHT?

SPEAKER CREATION decoded_input = json.loads(input_json)decoded_input['registration_date'] = datetime.strptime(decoded_input['registration_date'], "%Y-%m-%dT%H:%M:%S”)return dbconn['speakers'].insert(decoded_input)> ObjectId('5142d2845db1362bb3155322')

SPEAKER RETRIEVAL retrieved = dbconn['speakers'].find_one({'name': 'Pablo'}, {'_id': 0})retrieved['registration_date'] = retrieved['registration_date'].strftime("%Y-%m-%dT%H:%M:%S")return retrieved

IT IS REALLY

STRAIGHT FORWARD!

WHAT IF WE WANT TO

CHANGE SPEAKERS DATA?

EXAMPLE: SPEAKER JSON {

"name": "Pablo Enfedaque",

"company": "Telefonica Digital",

"position": "R&D SW Engineer",

"accepted": true,

"registration_date": "2012-03-15T14:35:05",

"num_talks": 1,

”votes": 4.3, WAS AN INTEGER

"email": "pev@td.com"

}

SPEAKER CREATION decoded_input = json.loads(input_json)decoded_input['registration_date'] = datetime.strptime(decoded_input['registration_date'], "%Y-%m-%dT%H:%M:%S”)return dbconn['speakers'].insert(decoded_input)

SPEAKER RETRIEVAL retrieved = dbconn['speakers'].find_one({'name': 'Pablo'}, {'_id': 0})retrieved['registration_date'] = retrieved['registration_date'].strftime("%Y-%m-%dT%H:%M:%S")return retrieved

0 LINES CHANGED

INPUT VALIDATION NEEDED?

SPEAKER VALIDATION from rest_framework import serializersclass SpeakerSerializer(serializers.Serializer): name = serializers.CharField(max_length=150) company = serializers.CharField(max_length=150) position = serializers.CharField(required=False) accepted = serializers.BooleanField() registration_date = serializers.DateTimeField() num_talks = serializers.IntegerField() votes = serializers.FloatField() email = serializers.EmailField(max_length=150) def restore_object(self, attrs, instance=None): return attrs

SPEAKER CREATION decoded_input = json.loads(input_json)serializer = SpeakerSerializer(decoded_input)print dbconn['speakers'].insert(serializer.object)

SPEAKER RETRIEVAL retrieved = dbconn['speakers'].find_one({'name': 'Pablo'})serializer = SpeakerSerializer(retrieved)return serializer.object

DON’T LIKE TO WORK WITH DICTIONARIES / HASHES?

CUSTOMISE ATTRIBUTES ACCESS class AttrDict(dict): def __getattr__(self, name): try: return super(AttrDict, self).__getitem__(name) except KeyError, e: raise AttributeError(e) def __setattr__(self, name, value): if name in self: super(AttrDict, self).__setitem__(name, value) else: super(AttrDict, self).__setattr__(name, value)

USE DICTIONARIES AS OBJECTS decoded_input = json.loads(input_json)serializer = SpeakerSerializer(decoded_input)speaker_obj = AttrDict(serializer.object)print speaker_obj.companyprint speaker_obj['position']> Telefonica DigitalR&D SW Engineer

USE AN ORM?

NO

OBJECT-RELATIONAL MAPPER

NO RELATIONAL NO ORM

NEEDED

CONCLUSIONS

CONCLUSIONS •  MongoDB + dynamic languages = fastest development speed

•  14 months project with Oracle à 3 months project with MongoDB

•  REST API best practices

•  Use JSON

•  Use dictionaries / hashes

•  Access dictionaries as objects

•  No relational model à no ORM

•  No other mappers

•  Use decorators to handle AutoReconnect