Tag Archives: nosql

Property Level Security with Neo4j Enterprise

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In Neo4j 3.1 Enterprise edition, we introduced the first wave of security features that are coming down the pipeline. Now you can start off with Administrators, Architects, Publishers and Readers as built in default groups. You can read about their capabilities in the docs.

If you’ve been paying attention, you know Neo4j thrives under it’s dynamic customizability. The developers decided to let us build our own custom Roles and limit their capabilities to a set of Stored Procedures. With this, we can build any kind of access control we want, but let’s go for the jugular and let’s see how we can build property level security for Neo4j.
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Our own Multi-Model Database – Part 1

shittydb

I may be remembering this wrong, but I think it was Henry Rollins who once asked, “What came first, the shitty Multi-Model Databases or the Drugs?” His confusion was over whether:

A) there were a bunch of developers dicking around with their Mac laptops and they wrote a shitty database, put it on github, posted on hacker news, and then other developers who were on drugs started using it or…

B) there were a bunch of developers on ketamine and ecstasy and somebody said lets write a shitty database

I think “A” is what probably happens and how we end up with over 300 databases on DB Engines. But what about “B” ? Well I don’t have any good stuff lying around, but I did hurt my foot the other day and the doctors gave me some Tramadol, so lets down some of that and see what happens.
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News Feeds

Ron Burgundy Gets Hungry

Ron Burgundy (in Anchorman) gets Hungry

The “News Feed” is a core feature of social networks like Twitter, Facebook, or Vine (RIP). Let’s take a look at how we could model and implement this in Neo4j. Our social network needs Users (otherwise it would be kinda empty) that FOLLOW each other (otherwise it would not be very social). Those users need to POST some Messages (otherwise it would be boring). Here is our first attempt at a model (using Arrows):
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Catalogs and Hierarchies

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When I was younger, friends and I would play a role playing game called “Shadowrun“. The game draws elements from science fiction, crime dramas, and magic and blends them all together to make a fun mess. You could be a Dwarf Shaman, an Elf Decker, a Human Rigger, an Orc Adept, a Troll Street Samurai or whatever combination your heart desired. Choosing a gender, race and archetype was just the beginning a more important question: “What is your character going to wear and take on missions?”
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Custom Importers

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When it comes to getting data into Neo4j, you have a ton of options. You can use LOAD CSV from Cypher, you can use the Import Tool, you can use the JDBC connector in APOC, and possibly a few more options I’m forgetting. Some of these require the data to be in a specific format, others that you write a little custom cypher. These work very well most of the time, but sometimes you run into data in weird shapes and coming in from vendors who aren’t willing to change just for you. What do you do in that case? Well, you write a custom importer. I’m going to show you how by importing the Cities database from MaxMind.
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Flight Search with the Neo4j Traversal API

Screen Shot 2015-08-30 at 2.21.07 AM

Before Cypher came along, if you wanted to describe a graph traversal in Neo4j you would use the Traversal Framework Java API. The Traversal API is one of the many hidden gems of Neo4j and today we are going to take a closer look at it. Traversing a graph is about going on a journey. All journeys have a starting point (or points) so that’s the first thing we have to do, figure out where in the graph we begin. It can be a single node, or multiple ones, but they will go on the journey following the same rules, so its easier if it’s just one node or nodes of the same “type”.
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Using the Testing Harness for Neo4j Extensions

harness

I’ve been creating both unit tests and integration tests for Neo4j Unmanaged Extensions for far too long. The Neo4j Testing Harness was introduced in version 2.1.6 to simplify our lives and just do integration tests. Let’s try it on and see just how awesome we look. First thing we need to do is add the dependency to our project:
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Importing the Hacker News Interest Graph

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Graphs are everywhere. Think about the computer networks that allow you to read this sentence, the road or train networks that get you to work, the social network that surrounds you and the interest graph that holds your attention. Everywhere you look, graphs. If you manage to look somewhere and you don’t see a graph, then you may be looking at an opportunity to build one. Today we are going to do just that. We are going to make use of the new Neo4j Import tool to build a graph of the things that interest Hacker News.
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Triggers in Neo4j

al-capones-gun

One of the often overlooked features in Neo4j is the “TransactionEventHandler” capabilities… better known in the database world as “Triggers“. When a transaction occurs, we can analyze that event and decide to take some action. To accomplish this, we’ll write a “Kernel Extension” ( a little different from the Unmanaged Extensions we’ve seen on this blog ) to tie in our trigger.

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Connected

connected

Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives is a mind bending look at how no matter how individual we think we are, the people around us have a great amount of influence in our lives. One of the authors James Fowler was at GraphConnect 2012 and gave a presentation on this idea:
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