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: Perfect use case for #Bitcoin and #QR codes found »
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: Do not get stuck in #Java with Out of Memory… »
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: #Apache #Kafka solutions going mainstream »
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: A solution for kswapd0 going haywire on #Linux »
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: #RaspberryPi #AIY Project with #ModMyPi case »
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: Drop a not null constraint with #SQL »
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: #RaspberryPi cluster with #ModMyPi case »
It looks like the Microsoft SQL Database Mirroring a feature I used a lot and for which posted a step by step tutorial that proved to be very popular was deprecated by Microsoft. In a news article on Microsoft site the alternative is presented “Basic Availability Groups (Always On Availability Groups)”. I will summarize in… Read More: #Microsoft SQL Server: Database #Replication (Mirroring) deprecated and replaced by… »
Running NetFlix on a Raspberry Pi is a fantastic way to carry your Netflix account with you in a light mode way without relying on a laptop or entering your credentials on unknown insecure terminals. You need: – a Raspberry PI – preferably with head radiators or better already equipped with a with a fan.… Read More: #RaspberryPI as portable #NetFlix media player »
I upgraded my personal network with another Ubiquiti device, this time a “UniFi AP-AC-Pro”. The sad part is that to get all the features, like extra control and statistics you need to install a Unifi Controller Software. I hate the idea of network software running on a Windows desktop so I tried to find a… Read More: Monitoring @ubnt based home network with @UNMS and @UnifiController with… »