Get fast random access to binary files, but also sequential when needed. How to layout?

I have about 1 billion datasets that have a DatasetKey and each has between 1 and 50 000 000 child entries (some objects), average is about 100, but there are many fat tails. Once the data is...

What are GC holes?

I wrote a long TCP connection socket server in C#. Spike in memory in my server happens. I used dotNet Memory Profiler(a tool) to detect where the memory leaks. Memory Profiler indicates the...

strict aliasing and memory alignment

I have performance critical code and there is a huge function that allocates like 40 arrays of different size on the stack at the beginning of the function. Most of these arrays have to have...

ld error: skipping incompatible.../gst/lib/libgstreamer-0.10.so when searching for -lgstreamer-0.10 .Hot to fix?

I'm trying to cross-compile qt4 for an embedded system. My embedded system is based on armv5 and my host PC has got a i686-32bit architecture. This is the command that I use to configure...

VNC only displaying the mouse cursor but nothing else

I have a RaspberryPi with Raspbian and x11vnc installed. I can: startx & x11vnc -usepw -background And then connect to the VNC Server using my Mac. However, after some event (it used to work at...

Installing MySQL 5.6 in Ubuntu 14.04 triggers removal of needed packages

So I was trying to make a fresh installation of MySQL 5.6 on Ubuntu 14.04.2 and for some reason it tried to remove needed packages, not without first complaining about some unmet dependencies....

Vagrant plugin load order

I am behind corporate proxy which is using self-sign certificate to intercept ssl trafic. So I have installed vagrant-ca-certificates to have certificate in vm. I am also using vagrant-omnibus to...

"A Stop Job is running for session 1 of user SeAL80s " in fedora 23 shutdown prosess

My System is Fedora 23 x86_64 running Xfce4 When system installed , i did: su # root to open sudo sudo vi to disable selinux sudo mkdir /usr/share/fonts/ to add extra fonts sudo chmod 755 fonts...

aerospike server can't start with unrecognized service information

I'm trying the community edition aerospike, I followed the tutorial to install the server on my ubuntu, whose version is ubuntu 14.04 LTS. When I wanted to start it with the command 'sudo service...

Building simple OpenGL program with Eclipse mingw-w64 on win7 64bit make error

I am trying to build a simple sample OPENGL program opengl-tutorial.org, followed their instruction in tutorial 1, but using Eclipse. Downloaded their source code, compiled with cmake, option...

Net::HTTPServerException causing Chef to fail

I'm attempting to set up a Rails environment with Vagrant and Chef by following this guide. I've used it in the past with success. When I run vagrant up it fails, and (I think) this is the...

Gray screen with cross cursor in TightVNC

I am trying to VNC to a Ununtu 16.04 from windows 10. I am getting a textured gray screen with cross cursor. Below is my log file: Xvnc Free Edition 4.1.1 - built Feb 25 2015 23:02:21 Copyright...

How to Build Qt to Cross Compile for Raspberry Pi3 on Windows

I have been trying to build qt for raspberry pi3 on windows for 6 months. I have tried lots of tutorials, read lots of forums but there is no successful result. I can build qt on ubuntu 14.04 in...

This application failed to start because it could not find or load the Qt platform plugin "xcb" in ""

I have an application which runs using Qt5 (via PyQt). I am using miniconda and the python code has been cythonised. The code was setup on my local machine, the cython code produced from the...

VNC on Ubuntu 14.04 LTS

I have a Mac running OS X 10.11.6 and Ubuntu EC2 instance running 14.04LTS. I'm trying to get VNC running KDE from my Mac. XQuartz launches but I have not keyboard, or mouse control over...

How to translate X11 keycode back to scancode or hid usage id reliably

Almost self resolved. Background info linux keycode The below is from: linux_xmodmap_tutorial Scancode → a number your keyboard sends to a computer. For USB keyboards, it's defined by the USB...

C3.js chart doesn't read variable in load function

I'm using C3.js library and when I want add in the line chart one value dynamically, I call the function updateChartC3(action, values) with receives from PHP by AJAX and inside the function...

How to dockerize an app together with VNC (arduino IDE)

I'm trying to dockerize an arduino IDE on raspberry pi using this answer: https://stackoverflow.com/a/16311264/6791424 ps: I know how to pass the X server to the docker container but in this case...

The command '/bin/sh -c apt-get install erlang' returned a non-zero code: 1

I am a beginner in Docker and am using Ubuntu 18.04 as a Host machine. While searching for the solution the only thing I got was to increase the VM disk size as it is happening due to low...

How to minimize an ubuntu docker image which needs only git, cron and openjdk-8-jre

Testing some docker project so after playing with alpine, I would like to use ubuntu:bionic for production. I decided to roll out my own image but the problem is that it's 600MB+ . REPOSITORY ...

Rails & Docker: configure bundler to run bundle install in a docker build for Rails.4.2.6?

I am having so much trouble with docker. It seems to be a pattern. I have a dockerfile which installs Node.js and Yarn from source repositories fine. I install ruby from the get-apt repositories...

Qt linking error when running OpenCV python application in Ubuntu

I am running 4.1.0 with python 3.7.3. I installed opencv using conda: conda install -c conda-forge opencv I don't have any experience using Qt. I am simply trying to show an image or a video...

xkbcommon: ERROR: failed to add default include path

Whenever I start a python script that tries to access the keyboard, for example, with OpenCV's waitKey() method, I get the following error: Qt: Failed to create XKB context! Use QT_XKB_CONFIG_ROOT...

cmake error with codeblocks mingw and glfw in windows 10

Hello I am just starting out in programming and I am trying to setup CodeBlocks with mingw compiler and glfw under Windows 10. When trying to cmake the CMakeList.txt in the glfw folder, I get a...

Issues with xdotool

So I have been trying to sort out xdotool. I can get things like :~$ xdotool getmouselocation x:347 y:310 screen:0 window:90 and :~$ xdotool getdisplaygeometry 1366 768 but am receiving to...

Running apt-get install within Docker container: "Unable to connect to deb.debian.org" part-way through installing dependencies

I'm trying to build a docker container on a Raspberry Pi 3B. I need to install gpac for MP4Box. Dockerfile FROM python:3.8-buster RUN apt update && apt install curl gpac -y ENV...

Heroku requirements.txt dependencies not installing, returning ImportError: No module named selenium

I'm trying to deploy a Python script on Heroku that utilizes Selenium. I have my Python script file, Procfile, requirements.txt(created via pipfreeze), and runtime.txt files all created in my root...

Qt for Raspberry pi: "Could not find DRM device!"

I've built Qt (with cross-compiler) from Ubuntu VM to Raspbian (Raspberry pi model 3 B+), so it can deploy apps via ssh. Qt config: Building on: linux-g++ (x86_64, CPU features: mmx sse...

/usr/bin/env: ‘python’: No such file or directory

I am trying install Docker with Minetest thought Make. I download Dockerfile Makefile and supervisord.conf from here: https://github.com/zaoqi/minetest-novnc-docker Use fromdos to convert them to...