Ingest How-To: Real-time Graph Analytics for Kafka Streams with Quine
Blog #5 in the Ingesting Data series. A step-by-step guide to adding Quine's high-volume graph analytics inline with your Kafka-based event streams.
June 20, 2022
Quine adds Real-time Graph Analytics to Kafka Event Streams
Kafka is the tool of choice for data engineers when building streaming data pipelines. Adding Quine into a Kafka-centric data pipeline is the perfect way to introduce streaming analytics to the mix. Adding business logic directly into an event pipeline allows you to process high-value insights in real time.
Simple Streaming Pipeline
Consider this straightforward, minimum viable streaming pipeline.
In this simple pipeline, Vector will produce events (`dummy_log` lines) once a second and stream them into a Kafka topic (`demo-logs`) where an ingest stream from Quine will transform the log events into a streaming graph.
Setting up Vector
Start by installing Vector in your environment. My examples use macOS and may need slight modifications to work correctly in your environment. I installed Vector with `brew install vector`, which includes a sample ` Vector.toml` config in `/opt/homebrew/etc/vector`. I extended the sample Vector config to build our pipeline.
Run Vector to get a feel for the events that Vector emits.
❯ vector -c /opt/homebrew/etc/vector/vector.toml
Vector generates dummy log lines from a built-in demo_logs source. The log lines are transformed in Vector using the parse_syslog and emit a JSON object.
"message": "Take a breath, let it go, walk away",
Once Vector is emitting log entries, we need to connect that output to Kafka by adding in a Kafka sink element into the Vector.toml file.
Kafka is the next step in the pipeline. I set up a single node Kafka cluster in Docker. There are more than enough examples on the internet of how to set up a Kafka cluster in Docker, and please set up the cluster in a way that fits your environment. My cluster uses a docker-compose file that launches version 7.1.1 of Zookeeper and Kafka containers.
Start the Kafka cluster and create a topic called demo-logs.
I had to run the docker compose up command a couple of times before
both the Zookeeper and Kafka containers launched cleanly. Make sure the containers
fully load at least once before including the -d option to run them in detached mode.
The ingest query creates nodes using `idFrom()`, populated them with the properties that it received from Kafka, and didn't create any relationships. We can make this node more useful by giving it a label and removing parameters that are not interesting to us. Additionally, using `reify.time()`, I can associate the node with a `timeNode` to stitch together events that occur across the network in time.
Analyzing the sample data
Quine has a web-based graph explorer that really comes to life once you have a handle on the shape of the streaming data. But I am starting from the beginning with a bare-bones recipe. For me, when I start pulling apart a stream of data, I find that using the API to ask a few analytical questions serves me well.
I'll use the `/query/cypher` endpoint to get a feel for the shape of the sample data streaming from Kafka. I don't recommend doing a full node scan on a mature streaming graph, but my streaming graph is still young and small.
Using my REST API client of choice, I POST a Cypher query that returns the metrics (counts) for parameters that are interesting.
That's a lot of JSON results to review; let's take this over to a Jupyter Notebook to continue the analysis. My REST API client includes a Python snip-it tool that makes it really easy to move directly into code without having to start from scratch.
In Jupyter, within a few cells, I had the JSON response data loaded into a Pandas DataFrame and an easy to review textual visualization of what the sample data contains.
I let the pipeline run while I developed simple visualizations of the metrics. Right away, I could see that the sample data Vector produces is random and uniformly distributed across all of the parameters in the graph. And after 15000 log lines, the sample generation exhausted all permutations of the data.
Conclusions and Next Steps
I learned a lot about streaming data while setting up this pipeline. Vector is a great tool that allows you to stream log files into Kafka for analysis. Add a Quine instance on the other side of Kafka, and you are able to perform streaming analytics inside a streaming graph using standing queries.
Use the same workflow to develop an understanding of streaming data that you do for data at rest
Perform streaming analysis by connecting Quine to your Kafka cluster
Use Cypher ingest queries to form the graph within a Quine ingest stream.
Quine is open source if you want to run this analysis for yourself. Download a precompiled version or build it yourself from the codebase Quine Github. I published the recipe that I developed at `https://quine.io/recipes`.
Have a question, suggestion, or improvement? I welcome your feedback! Please drop into Quine Slack and let me know. I'm always happy to discuss Quine or answer questions.
And if you're interested in learning more about building a streaming graph from various ingest sources., check out previous installments in this blog series: