Nenad Božić

Functional testing series This post continues the story about functional testing which I referred to in Blackbox Testing Microservices. In that post we had a clear case of testing a system as blackbox as it had input and expected output but all parts of the system were under our control. There were no external dependencies. […]

In first part of this blog post series we covered basic settings which can give you few fast wins when tuning performance. We explained how you can tune pooling options to send more parallel request over the wire and we explained how you can decrease socket timeout to get fail fast scenario, where you can handle this […]

When people think of tuning Apache Cassandra to perform better, their first instinct usually is to look into hardware, JVM or Cassandra configuration. But this is only one side of things, the client application which connects to Cassandra database can be tuned as well. Applications which store and read from Cassandra use a driver to […]

In our previous post we referred to the subject of having logs in a central place and viewing aggregated data from all the nodes, in order to figure out what has happened at a certain point in time throughout the system. In addition to log information, it is important to have all the metrics at your disposal, […]

Working on high nines where the latency of every query matters is a whole different beast in comparison with normal Cassandra use cases where measurements on 99.9% or even 99% are enough. We recently worked on a project which had really tight latencies (threshold in milliseconds on 99.999% of requests) and we needed latency measurement […]

Browsing through logs is always hard, even when you are on a single node system. You are scrolling up and down, trying to figure out what events happened before a certain error. Often you want to see what followed after the error which happened, then you go back again to see the actual cause etc. […]

Microservice architecture on the one hand, and distributed systems on the other, brought new challenges to the IT world. Here are two of them that are becoming increasingly noticeable: management of distributed systems with many nodes which involves deployment and orchestration and monitoring of those systems. Back in the days, you had a single machine […]

Apache Cassandra is great for handling huge volumes of data. Everything works really great when you know your data patterns up front and you can make certain decisions based on that experience. We have recently worked for a marketing company which serves ads based on user behavior. The assumption of the use case and data […]

Within several previous projects, we have held consultations for development teams coming from the relational world and adopting Cassandra database. The experience gained from those projects has triggered me to publish my learning guidelines for it. We see a pattern when adopting Cassandra and it involves taking a shortcut rather than an in-depth understanding of how Cassandra works. I will try to address those shortcuts and red flags and give you advice on how to start.