Graph on Micha Kops' Tech Notes

Quick Apache NiFi Setup with Docker

Tue, 08 Feb 2022 00:00:00 +0100

Steps

Pull image and run with ports exposed:

docker run --name "nifi" -p 8443:8443 -d apache/nifi:latest

Fetch the generated username and password from the logs:

docker logs nifi | grep -A1 "Generated Username"

Generated Username [8f6d91f7-733e-40cf-b900-059ea9dccbf2]
Generated Password [v7KGiiRYLJL2+HzhKOqz1rbgiPOaWz0B]

Now we may enter the https://localhost:8443/nifi/login in our browser, accept the security exemption and login with the credentials from above, voila!

Installing additional connectors

I have found a nice summary on the following GitHub repository:

Managing Architecture Decision Records with ADR-Tools

Sun, 27 May 2018 00:00:00 +0200

Every software project includes a set of architecture decisions defining boundaries and constraints for further design and implementation.

It’s important to document those decisions somehow or else a development team might not know which decisions where made and with which assumptions.

Or they know the decision but are missing the context and the consequences and therefore decisions are blindly accepted or blindly changed.

In the following short tutorial I will show how to structure architecture decisions in so called Architecture Decision Records and how to manage them with a simple tool named ADR-Tools.

Implementing, Testing and Running Procedures for Neo4j

Tue, 27 Feb 2018 00:00:00 +0100

A lot of features are already included in the Neo4j graph database system but sometimes we want to extends its capabilities and implement functions and procedures by ourselves that we may reuse.

In the following tutorial I will demonstrate how to implement a procedure for Neo4j, how to write and run tests using JUnit and an embedded graph database and last but not least how to setup Neo4j with Docker and our stored procedure installed in no time.

Software Architecture Exploration and Validation with jqAssistant, Neo4j and Cypher

Sun, 31 Dec 2017 00:00:00 +0100

I have written about other software system analyzing and validation tools before but today I would like to introduce a new tool named jqAssistant that supports software architects, developers and analysts in a variety of tasks like analyzing given structures, validating architectural or quality constraints and generating reports.

Therefore jqAssistant analyzes given projects or artifacts and stores the gathered information – that is enriched by a variety of existing plugin-ins – in a Neo4j graph database.

Object Graph Mapping by Example with Neo4j OGM and Java

Mon, 18 Jul 2016 00:00:00 +0200

When integrating a Neo4j database into a Java application a developer often needs to map nodes and edges of the graph to corresponding Java classes of the domain model.

Neo4j OGM eases this work and allows us to map our domain objects to the graph database using simple annotations – similar to the Java Persistence API (JPA) for relational database management systems.

In the following tutorial I’d like to demonstrate how to use Neo4j OGM to build a simple train timetable planner and a permission system mapping between graph, nodes, edges and POJOs.

A short Overview of Neo4j Indexing Strategies

Sun, 25 Jan 2015 00:00:00 +0100

When it comes to indexing in a Neo4j graph database, different options exist for a developer to create and maintain the index.

In the following short examples I’d like to demonstrate different possibilities for index management.

Figure 1. Simple Domain Model

Dependencies

Only one dependency is needed to run the following examples and start an embedded neo4j server – I’m using Gradle here to manage my dependencies but Maven, Ivy, SBT should work without a problem, too.

Neo4j Graph Database Tutorial: How to build a Route Planner and other Examples

Fri, 20 Jan 2012 00:00:00 +0100

Often in the life of developer’s life there is a scenario where using a relational database tends to get complicated or sometimes even slow – especially when there are fragments with multiple relationships or multiple connections present. This often leads to complex database queries or desperate software engineers trying to handle those problems with their ORM framework.

A possible solution might be to switch from a relational database to a graph database – and – neo4j is our tool of choice here. In the following tutorial we’re going to implement several examples to demonstrate the strengths of a graph database .. from a route planner to a social graph.