DepC uses Kafka to manage the graph in Neo4j. Each team has its own topic and can push messages in it using its own credentials.

Nested message

You can create new nodes and relationships using the following format :

  "source": {
    "label": "A",
    "name": "foo",
    "props": {
      "from": 1515241242,
      "to": 1515244850
  "target": {
    "label": "B",
    "name": "bar",
    "props": {
      "from": 1533636245,
      "to": 1533643445
  "rel": {
    "from": 1527847440,
    "to": 1527854640

This message will create 2 linked nodes :

DepC Kafka 1

Only the source key is mandatory, it means the target, rel and props keys are optionals. So the smallest message can be the following one :

 "source": {
    "label": "A",
    "name": "foo"
DepC Kafka 2

Flat message

If you Kafka client does not support the nested structure for your message, or if your prefer this form, you can also send us a flat message :

  "source_label": "A",
  "source_name": "foo",
  "source_from": 1515241242,
  "source_to": 1515244850,
  "target_label": "B",
  "target_name": "bar",
  "target_from": 1533636245,
  "target_to": 1533643445,
  "rel_from": 1527847440,
  "rel_to": 1527854640

The only mandatory keys are source_label and source_name.

Messages validation

DepC validates messages before converting them into Neo4j format. Here are the rules :

Field Rule Examples
Label {“type”: “string”, “pattern”: “^[A-Z]+[a-zA-Z0-9]*$”} MyLabel, Mylabel, My123Label
Name {“type”: “string”, “pattern”: “^[!#-&(-[\]-_a-~]+$”} Foo, foo, foo123bar, #F$o%ob&/a-r.
From {“type”: “integer”, “minimum”: 0} 0, 100, 10000
To {“type”: “integer”, “minimum”: 1} 1, 100, 10000

Example script

Here is a simple example in Python :


First, you may need to install this dependency : pip install kafka-python==1.4.3

import json
import os
import ssl

from kafka import KafkaProducer

conf = {
    'bootstrap_servers': os.environ['DEPC_KAFKA_HOST'],
    'security_protocol': 'SASL_SSL',
    'sasl_mechanism': 'PLAIN',
    'sasl_plain_username': os.environ['DEPC_KAFKA_USERNAME'],
    'sasl_plain_password': os.environ['DEPC_KAFKA_PASSWORD'],
    'ssl_context': ssl.SSLContext(ssl.PROTOCOL_SSLv23),
    'ssl_check_hostname': False,
    'client_id': os.environ['DEPC_KAFKA_TOPIC'],
    'value_serializer': lambda v: json.dumps(v).encode('utf-8')
p = KafkaProducer(**conf)

message = {
    "source": {
        "label": "Cluster",
        "name": "cluster020.ovh.net"
    "target": {
        "label": "Server",
        "name": None

for name in ['ns375001.ip-xx-xxx-xx.eu', 'ns375002.ip-xx-xxx-xx.eu', 'ns375003.ip-xx-xxx-xx.eu']:
    message['target']['name'] = name
    p.send(os.environ['DEPC_KAFKA_TOPIC'], message)

The following graph will be created :

DepC Kafka 3