Tag Archives: github

Building a Twitter Clone with Neo4j – Part Three

In part two we defined our API and got registering a user, checking a user and getting a user profile. A social network of unconnected people doesn’t live up to its name, so let’s go ahead and build the ability to follow people.

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Neo4j is faster than MySQL in performing recursive query

5mysql

A user on StackOverflow was wondering about the performance between Neo4j and MySQL for performing a recursive query. They started with Neo4j performing the query in 240 seconds. Then an optimized cypher query got them down to 40 seconds. Then I got them down to…
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Writing a Cypher Stored Procedure

luke-cage-jidenna

I’ve been so busy these last 6 months I just finally got around to watching Luke Cage on Netflix. The season 1 episode 5 intro is Jidenna performing “Long live the Chief” and it made me pause the series while I figured out who that was. I’m mostly a hard rock and heavy metal guy, but I do appreciate great pieces of lyrical work and this song made me take notice. Coincidently on the Neo4j Users Slack (get an invite) @sleo asked…
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Our own Multi-Model Database – Part 3

shitty3

If you haven’t read part 1 and part 2 then do that first or you’ll have no clue what I’m doing, and I’d like to be the only one not knowing what I’m doing.

We’ve built the beginnings of this database but so far it’s just a library and for it to be a proper database we need to be able to talk to it. Following the Neo4j footsteps, we will wrap a web server around our database and see how it performs.

There are a ton of Java based frameworks and micro-frameworks out there. Not as bad as the Javascript folks, but that still leaves us with a lot of choices. So as any developer would do I turn to benchmarks done by other people of stuff that doesn’t apply to me, and you won’t believe what I found –scratch that, yes you will, I got benchmarks.
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OUR OWN MULTI-MODEL DATABASE – PART 2

shitty2

If you haven’t read part 1 then do that first or this won’t make sense, well nothing makes sense but this specially won’t.

So before going much further I decided to benchmark our new database and found that our addNode speed is phenomenal, but it was taking forever to create relationships. See some JMH benchmarks below:

Benchmark                                                           Mode  Cnt     Score     Error  Units
ChronicleGraphBenchmark.measureCreateEmptyNodes                    thrpt   10  1548.235 ± 556.615  ops/s
ChronicleGraphBenchmark.measureCreateEmptyNodesAndRelationships    thrpt   10     0.165 ±   0.007  ops/s

Each time I was creating 1000 users, so this test shows us we can create over a million empty nodes in one second. Yeah ChronicleMap is damn fast. But then when I tried to create 100 relationships for each user (100,000 total) it was taking forever (about 6 seconds). So I opened up YourKit and you won’t believe what I found out next (come on that’s some good clickbait).
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Bidirectional Traversals in Space

firefly

If you have never watched Firefly, then stop whatever you are doing and get to it, you can come back and read this post later. Ok good, now where were we. Firefly. The series is set a few hundred years from now, after people begin to terraform a new star system and it follows the adventures of the renegade crew of Serenity, a “Firefly-class” spaceship whose work consists of cargo runs or smuggling while failing to stay out of trouble. There is no faster than light travel in this series, so ships can’t just “warp” where ever they want. Instead they travel about from planets and moons, exchanging cargo, refueling and trying to make a living. We are going to model “The Verse” of Firefly in Neo4j, and see how we can find routes to move our illicit cargo from one place to another.
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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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Scaling Concurrent Writes in Neo4j

concurrent writes

A while ago, I showed you a way to scale Neo4j writes using RabbitMQ. Which was kinda cool, but some of you asked me for a different solution that didn’t involve adding yet another software component to the stack.

Turns out we can do this in just Neo4j using a little help from the Guava library. The solution involved a background service running that holds the writes in a queue, and every once in a while (like say every second) commits those writes in one transaction.
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It’s over 9000! Neo4j on WebSockets

it__s_over_9000_

In the last blog post we managed to run Neo4j at Ludicrous Speed over http using Undertow and get to about 8000 requests per second. If we needed more speed we can scale up the server or we can scale out to multiple servers by switching out the GraphDatabaseFactory and using the HighlyAvailableGraphDatabaseFactory class instead in Neo4j Enterprise Edition.

But can we go faster on a single server without new hardware? Well… yes, if we’re willing to drop http and switch to Web Sockets.

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