SanjuroE's blog

Debian 10 and higher (e.g. Buster or Bullseye) no longer provide Java 8. However certain software, including Sonatype Nexus, still is not compatible with versions higher than 8. In this past it was easy to install AdoptOpenJDK. However now that AdoptOpenJDK has moved to the Eclipse Foundation and is called... [Read More]

Tags: java ops group9

Custom hostname resolution in Java

Endless possibilities incur increased complexity

Posted on October 31, 2021

Custom hostname resolution has been proposed for Java 18 and would allow secure DNS implementations without operating system support as well as faster lookups in cloud environments. However it also makes diagnosing network problems harder. [Read More]

Tags: java ops group9

UEFI Boot Walkthrough

From power-up to systemd

Posted on June 20, 2021

Booting a modern PC is a rather complex affair with many moving parts. While all individual parts are described in create detail, the overall process is less well documented. In this blog post I will attempt to provide a high-level overview, describing the components involved, their interfaces, and providing links... [Read More]

Tags: ops uefi

A future without JavaScript

Web programming without HTML, JS, or CSS

Posted on May 29, 2021

A while ago I came across an article indicating that Google was planning to switch to using the Canvas API for Google Docs. This let to some contemplation as to why Google is doing this and what this could mean for the future of the web. [Read More]

Tags: javascript opinion group9

nftables basics

Introduction to nftables

Posted on May 24, 2021

nftables is a very powerful packet filtering framework, otherwise known as a firewall. In this tutorial I will introduce the most important mechanism which will allow you to build your own firewall. [Read More]

Tags: ops sec

iptables vs nftables

Upgrade, or not yet

Posted on May 23, 2021

nftables will eventuelly replace iptables as the Linux kernel packet classification framework, more comply referred to as ‘the firewall’. Both are still maintained, and will be for a while. So which one should you choose? [Read More]

Tags: ops sec

Creating an unmarshaller using bytecode

An example of code generation at deploy-time

Posted on May 15, 2021

In this blog we will create a simple unmarshaller at deploy-time using bytecode and measure its performance. [Read More]

Tags: java group9

Generating an unmarshaller using annotations

An example of code generation at compile-time

Posted on May 5, 2021

In this blog we will construct a simple unmarshaller at compile-time using an annotation processor and measure its performance. [Read More]

Tags: java group9

Debugging an annotation processor

Using JUnit5 and Java Tool API

Posted on May 2, 2021

An annotation processor is a plug-in to the Java compiler itself. So in order to debug a processor it either needs to run inside the compiler itself or be provided with a mock Compiler API. [Read More]

Tags: java

Safe reload with nftables

Reducing the risk of getting locked out

Posted on May 1, 2021

As of Debian Buster the default package filtering mechanism is nftables replacing iptables1. When using iptables I have always used the excellent Shorewall to help manage the firewall. Unfortunately Shorewall does not, and probably never will, support nftables2. Nftables has a number of improvements over iptables including features which provide... [Read More]

Tags: ops sec

Constructing an unmarshaller using reflection

An example of code generation at run-time

Posted on April 25, 2021

In this blog we will construct a simple unmarshaller at runtime using reflection and measure its performance. [Read More]

Tags: java group9

Writing an unmarshaller by hand

An example of code generation at code-time

Posted on April 11, 2021

In this blog we will write a small unmarshaller by hand at code-time and measure its performance. [Read More]

Tags: java group9

Multiple Redis databases on Debian

Running multiple Redis instances on a Debian host

Posted on April 3, 2021

Occasionally you may want to run multiple Redis database on the same host. [Read More]

Tags: ops

Phases for generating code

Code-time, compile-time, deployment-time, and run-time

Posted on March 27, 2021

Code is generated at many phases during the development & deployment cycle. Everyone is familiar with compile-time at which the compiler generates (byte)code. However code is generated at other times/phases as well. In this post I divide code generation into four phases. I will also discusses some of the benefits... [Read More]

Tags: java

Time sync KVM guest on Debian

Using PTP to synchronize the time of a KVM guest VM

Posted on March 14, 2021

Synchronizing the time inside KVM guests is essential for a large number of reasons, including correlating logs from multiple guests and Maildir locking. [Read More]

Tags: ops

SanjuroE's blog

Java 8 on Debian 10+

Alternative for AdoptOpenJDK

Custom hostname resolution in Java

Endless possibilities incur increased complexity

UEFI Boot Walkthrough

From power-up to systemd

A future without JavaScript

Web programming without HTML, JS, or CSS

nftables basics

Introduction to nftables

iptables vs nftables

Upgrade, or not yet

Creating an unmarshaller using bytecode

An example of code generation at deploy-time

Generating an unmarshaller using annotations

An example of code generation at compile-time

Debugging an annotation processor

Using JUnit5 and Java Tool API

Safe reload with nftables

Reducing the risk of getting locked out

Constructing an unmarshaller using reflection

An example of code generation at run-time

Writing an unmarshaller by hand

An example of code generation at code-time

Multiple Redis databases on Debian

Running multiple Redis instances on a Debian host

Phases for generating code

Code-time, compile-time, deployment-time, and run-time

Time sync KVM guest on Debian

Using PTP to synchronize the time of a KVM guest VM