, 1 min read
I use the Hiawatha web-server on my servers. For example, this blog runs on Hiawatha. Recently I needed a web-server on Red Hat Enterprise. Unfortunately, Red Hat does not provide Hiawatha directly on its Satellite program, but Lighttpd was there. I also wanted to use PHP and the connection should…
, 2 min read
As I have moved my blog from WordPress to eklausmeier.goip.de, I wanted to know if I am really getting better response times across the globe. WordPress always felt slow. Below measurements will confirm this. Pingdom.com is a monitoring and performance measurement website. See Wiki article. The…
, 3 min read
GoAccess is a remarkable analyzer for your log-files written by the web-server. For example, GoAccess can read and analyze the log-files from Apache web-server. In the same vein, after some configuration, it can also read and analyze the log-files from Hiawatha web-server. The Hiawatha web-server…
, 3 min read
The blog eklausmeier.wordpress.com is no longer maintained. I moved to eklausmeier.goip.de, i.e., this one. During migration I corrected a couple of minor typos and dead links. Main reasons for the move: This new WordPress editor put the last nail in the coffin, existing content is garbled once…
, 5 min read
Task at hand: Call Cobol (=GnuCOBOL) from PHP. I used FFI for this: <?php $cbl = FFI::cdef("int phpsqrt(void); void cob_init_nomain(int,char**); int cob_tidy(void);", "/srv/http/phpsqrt.so"); $ffj0 = FFI::cdef("double j0(double);",…
, 1 min read
Problem at hand: There are multiple machines running SSHGuard. Each of these machines accumulates different sets of blacklists. Task: Add disjoint IP addresses from one machine to another machine's blacklist. 1. Copy from "master" machine: scp -p master:/var/db/sshguard/blacklist.db…
, 3 min read
Well known static site generators are Hugo (written in Go), Pelican (written in Python), Grav (written in PHP), or Eleventy (written in JavaScript). For a list of static site generators see Jamstack (322 generators listed) or Static Site Generators (460 generators listed). The following three…
, 3 min read
J-Pilot 1.8 still relies on GTK+ 2, which is heading towards planned deprecation. The entire work to migrate to GTK+ 3 is done by volunteers, Judd Montgomery and David Malia. This post is about testing this new experimental branch feature-gtk3 from GitHub. Installing this branch is…
, 5 min read
To ban annoying ssh access to your Linux box you can use fail2ban. Or, alternatively, you can use SSHGuard. SSHGuard's installed size is 1.3 MB on Arch Linux. Its source code, including all C-files, headers, manuals, configuration, and makefiles is 100 KLines. ~~In contrast,~~For fail2ban the…
, 1 min read
Assume three computers A, B, and C. A can connect to B via ssh, but A cannot connect to C, but B can connect to C. A -> B -> C On A open ssh as SOCKS-server with ssh -N -D 9020 user@B Now on A one can use brave --proxy-server="socks5://localhost:9020" The browser will then show…
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Task at hand: Generate random numbers which follow a lognormal distribution, but this drawing is governed by a Poisson distribution. I.e., the Poisson distribution governs how many lognormal random values are drawn. Input to the program are $\lambda$ of the Poisson distribution, modal value and…
, 2 min read
For comparing different machines I invert the Hilbert matrix $$ H = \left(\begin{array}{ccccc} 1 & {1\over2} & {1\over3} & \cdots & {1\over n} \\ {1\over2} & {1\over3} & {1\over4} & \cdots & {1\over n+1} \\ {1\over3} &…
, 3 min read
I repeatedly forget to remember when my hard-drive or SSD was first formatted. Command for this is dumpe2fs. This command is part of package e2fsprogs. Example: # dumpe2fs -h /dev/sda1 dumpe2fs 1.45.6 (20-Mar-2020) Filesystem volume name: <none> Last mounted on: /boot Filesystem…
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Folgendes schrieb ich an die Firma Unitymedia, jetzt Vodafone: Ich möchte gerne meine Rufnummer XXX über meine YYY Telefonanlage via VoIP betreiben. Ich verwende den von Ihnen bereitgestellten Router "Vodafone Station". Meine Kundennummer lautet ZZZ. Ich benötige nun folgende sieben…
, 2 min read
With GraalVM you can now fully compile a Java file to a native binary. This is also called AOT, ahead-of-time compilation. Compilation is very slow, and resulting binary is huge as it must contain all code which might be referenced. In contrast the class file usually is quite small. Though, it is…
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I repeatedly noticed that my Microsoft Windows 10 laptop is noticeably slow when restarted. This time I rebooted the laptop and just watched what happened in task manager. Below are the results. Waiting for more than 10 minutes doing nothing: one third of the machine is loaded with managing its…
, 44 min read
window.MathJax = { tex: { tags: 'ams' } }; Introduction 1. Preliminaries 2. State of the art 3. Algorithms 3.1 Algorithm: ABORT 3.1.1 ABORT for open online Dial-a-Ride 3.1.2 ABORT for closed online Dial-a-Ride 3.2 Algorithm: ABORT-AND-WAIT (AAW) 3.2.1 AAW for closed online…
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This blog was viewed more than 110.000 times since its inception and had more than 84.500 visitors. The averages per month are: The most popular posts this year are: The most popular posts over all years are: Distribution of countries accessing this blog over last 365 days, USA is number one,…
, 2 min read
Main source for trouble-shooting is Arch-Wiki UEFI. It describes the commands: bcfg within UEFI shell Linux command efibootmgr 1. It is ighly recommended to install the UEFI-shell, which is in package edk2-shell. On Asrock copy cp -p /usr/share/edk2-shell/x64/Shell_Full.efi /boot/shellx64.efi So…
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In continuation of blog-post SSD Speed on Dell XPS 13 9350, here are performance measurements for a Samsung EVO 970 Plus in Dell XPS 13. Caveat from Dell xps 13 9350 and Samsung 970 evo M.2 nvme Compatability?: However, be aware that although the XPS 13 9350 uses a PCIe x4 configuration for its…