I’m quite a fan of Sonos audio equipment but recently had some trouble with some of the devices glitching and even cutting out whilst playing. Under the covers Sonos stuff is running Linux (of course) and exposes some diagnostics through a rudimentary frontend that you can access at http://<sonos player IP>:1400/support/review: Whilst this gives you the current state, you can’t get historical data on it. It felt like the problems were happening "all the time", but were they actually?

Logs are magical things. They tell us what an application is doing—or not doing. They help us debug problems. As it happens, they also underpin the entire philosophy of Apache Kafka, but that’s a story for another day. Today we’re talking about logs written by Kafka Connect, and how we can change the amount of detail written. By default, Kafka Connect will write logs at INFO and above. So when it starts up, the settings that it’s using, and any WARN or ERROR messages along the way - a missing configuration, a broken connector, and so on.

Just over a year ago, I put together the crudely-titled "Quick Thoughts on Not Writing a Crap Abstract" after reviewing a few dozen conference abstracts. This time around I’ve had the honour of being on a conference programme committee and with it the pleasure of reading 250+ abstracts—from which I have some more snarky words of wisdom to impart on the matter. Remind me…how does this conference game work? Before we really get into it, let’s recap how this whole game works, because plenty of people are new to conference speaking.

Prompted by a question on StackOverflow I had a bit of a dig into how windows behave in ksqlDB, specifically with regards to their start time. This article shows also how to create test data in ksqlDB and create data to be handled with a timestamp in the past. For a general background to windowing in ksqlDB see the excellent docs. The nice thing about recent releases of ksqlDB/KSQL is that you can create and populate streams directly with CREATE STREAM and INSERT INTO respectively.

This was prompted by a question on StackOverflow to which I thought the answer would be straightforward, but turned out not to be so. And then I got a bit carried away and ended up with a nice example of how you can handle schema-less data coming from a system such as RabbitMQ and apply a schema to it. Note This same pattern for ingesting bytes and applying a schema will work with other connectors such as MQTT What?

In this post I want to build on my previous one and show another use of the Syslog data that I’m capturing. Instead of looking for SSH attacks, I’m going to analyse the behaviour of my networking components. Note You can find all the code to run this on GitHub. Getting Syslog data into Kafka As before, let’s create ourselves a syslog connector in ksqlDB: CREATE SOURCE CONNECTOR SOURCE_SYSLOG_UDP_01 WITH ( 'tasks.

I’ve written previously about ingesting Syslog into Kafka and using KSQL to analyse it. I want to revisit the subject since it’s nearly two years since I wrote about it and some things have changed since then. ksqlDB now includes the ability to define connectors from within it, which makes setting things up loads easier. You can find the full rig to run this on GitHub. Create and configure the Syslog connector To start with, create a source connector: