It is always fun to find new usage to UBNT devices. I just discovered that my UniFi AP-AC-Pro is a powerful monitoring tool for the Wi-FI enabled taxis. In a city that considers itself as one of the “Silicon Valleys” of Eastern Europe Internet is a must. Obviously in such an environment having a Hot-Spot… Read More »
Generation of core dumps that result in freezing the Linux system is another common issue in the new Linux kernels discussed on many forum threads. Same as the bug of kswapd0 discussed here Kswapd0 going haywire this can become very annoying. It seems that lately someone tries to add developer features turned on by default… Read More »
The rise of alternative banking is starting to get in the mainstream. Just 10 years ago there was a limited number of banks who offered the possibility to connect to your account online and get electronic statements. Now we see pressure to get the consumer closer and closer to the bank operations and make it… Read More »
We all know the fact that Bitcoin can be used to make anonymous and untraceable (up to a point) electronic payments. The QR code representation of a Bitcoin address makes it easier to send funds to someone (see also the donation QR code of this blog). Printed QR codes that cannot be altered without the… Read More »
In a JVM environment sometimes a thread can end up with an “OutOfMemoryError” exception. If this occurs we have a problem and most of the times this is so bad that we should no longer continue. The last thing you want in this case is to get stuck in a limbo state where your java… Read More »
I like when solutions you are excited about and are first seen as “experimental” start to go mainstream. This happened with containers (Docker, CoreOS, Kubernetes etc.) which are now the hottest topic in DevOps right now. The same is happening now for Apache Kafka which was adopted by no other than “Goldman Sachs” for their… Read More »
This is a common issue in the new Linux kernels discussed on many forum threads. There is a long thread here about this problem. In short the issue is that when you run out of memory “kswapd0” a kernel process than manages virtual memory will start moving “old memory entries” to swap. The “run out… Read More »
The AIY project from Google or Create a voice kit with your Raspberry Pi is a wonderful gift from Google. I got it last year after a long preorder wait from ModMyPi. The kit is nice comes with a do it yourself cardboard case, that is nice but obviously not to be used as a… Read More »
Sometimes very annoying things can be removed with a simple SQL commands which nobody remembers because is used so rarely. For example when we have to update a database schema and remove a not null constraint on a column. There is a short one liner for it: ALTER TABLE my_table ALTER COLUMN name DROP not… Read More »
The world smallest cluster has a new sleek case from ModMyPi the ModMyPi Cluster HAT Case The cluster is made of a Cluster HAT that creates the smallest cluster: 1 Raspberry Pi and 4 Raspberry Pi Zero for a total of 8 cores and 3GB of RAM. The case comes in a plain box: All… Read More »