November 2010 | Linux Blog

A Powerful HTTP / HTTPS / FTP / FTPS Load and Performance testing open-source tool - curl-loader

curl-loader is an open-source tool written in C-language, simulating application load and application behavior of thousands and tens of thousand HTTP / HTTPS and FTP / FTPS clients, each with its own source IP-address. In contrast to other tools curl-loader is using real C-written client protocol stacks, namely, HTTP and FTP stacks of libcurl and TLS/SSL of openssl, and simulates user behavior with support for login and authentication flavors.

The goal of curl-loader is to deliver a powerful and flexible open-source testing solution

curl-loader is useful for performance loading of various application services, for testing web and ftp servers and traffic generation. Activities of each curl-loader virtual client are logged and collected statistics includes information about resolving, connection establishment, sending of requests, receiving responses, headers and data received/sent, errors from network, TLS/SSL and application (HTTP, FTP) level events and errors.

System-wide Performance Profiler for Linux - Sysprof

Sysprof is a sampling CPU profiler that uses a Linux kernel module to profile the entire system, not just a single application. Sysprof handles shared libraries and applications do not need to be recompiled. In fact they don't even have to be restarted.

Sysprof has the following features:
  * profiles all running processes, not just a single application
  * Has a simple graphical interface
  * Shows the time spent in each branch of the call tree
  * Profiles can be loaded and saved

Improve Flash performance under Linux

Did you know that the Adobe Flash Player honors a few configuration files on the user’s local file system? There are 2 such files:

mm.cfg : user-local configuration file; lives in user’s home directory on Unix/Linux systems and is largely only useful when using content debugger versions of the Player

mms.cfg : system-wide configuration file, designed to allow administrators to set policy for all users on a system; lives in /etc/adobe on Unix/Linux systems.

There is a lengthy guide available that describes all of the various administration features and what the mms.cfg can do for you.

Configure Apache HTTP server with mod-pagespeed for high performance

mod_pagespeed is an open-source Apache module that automatically optimises web pages and resources on them. It does this by rewriting the resources using filters that implement web performance best practices. Web masters and web developers can use mod_pagespeed to improve the performance of their web pages when serving content with the Apache HTTP Server.

mod_pagespeed includes several filter that optimise JavaScript, HTML and CSS stylesheets. It also includes filters for optimizing JPEG and PNG images. The filters are based on a set of best practices known to enhance web page performance. Webmasters who set up mod_pagespeed in addition to configuring proper caching and compression on their Apache distribution should expect to see an improvement in the loading time of the pages on their websites.

Real time File Monitoring (File Watcher) UI Application - DaemonFS

To properly manage a PC it is recommended to know what changes occur during the use of the operating system or when you install / remove applications. With DaemonFS you can monitor the changes to file in real time.

DaemonFS lets you track modifications to your (or system configuration) files. Every time a file gets modified, a notification launched from the tray icon appears. a simple and effective file watcher.

DaemonFS may be used for reverse engineering, hard disk usage tracking, software analysis and more...

How to Compile and Run C# .NET application on Ubuntu - mono

Mono is a software platform designed to allow developers to easily create cross platform applications. It is an open source implementation of Microsoft's .Net Framework based on the ECMA standards for C# and the Common Language Runtime.

There are several components that make up Mono:

C# Compiler - The C# compiler is feature complete for compiling C# 1.0 and 2.0 (ECMA), and also contains many of the C# 3.0 features.

Mono Runtime - The runtime implements the ECMA Common Language Infrastructure (CLI). The runtime provides a Just-in-Time (JIT) compiler, an Ahead-of-Time compiler (AOT), a library loader, the garbage collector, a threading system and interoperability functionality.

Linux kernel patch makes desktop faster

These are great news, and are spreading all over the Linux world.

The patch, created by Linux kernel developer Mike Galbraith, is 233 lines long and tweaks the kernel scheduler and cutting down latency by a whopping factor of ten.

Phoronix has some demo videos showing the improvements the patch offers. Here is the video:

Below is the video of the Linux desktop when running the Linux Git kernel and the patch in question was applied but the auto-group scheduler was disabled via its sysfs interface.

Create Movies out of your pictures on Ubuntu Linux - PhotoFilmStrip

PhotoFilmStrip creates movies out of your pictures in just 3 steps. First select your photos, customize the motion path and render the video. There are several output possibilities for VCD, SVCD, DVD up to FULL-HD.

The effect of the slideshow is known as "Ken Burns". Comments of the pictures are generated into a subtitle file. Furthermore an audio file can be specified to setup the background musice for the slide show.

Resize, Rename and Convert Images on Linux - EasyImageSizer

EasyImageSizer is a simple application to compress, resize and rename Images. EasyImageSizer can reduce file size of most Photos because it uses a better compression than most Photo Cameras. Additional you can also reduce file size by reducing quality. Image transformation is also possible

To install EasyImageSizer on Ubuntu / Debian / openSUSE / Mandriva / Fedora / Windows, go to this page and download the proper installer for your distribution.

UI Application for Viewing and Analysing the contents of music audio file - Sonic Visualiser

The essential requisite for analysing recordings is a system that allows you to listen to them closely and flexibly, and for this purpose there is a application call - Sonic Visualiser, this free program (Sonic Visualiser is Free Software, distributed under the GNU General Public License (v2 or later) and available for Linux, OS/X, and Windows) is a highly customisable playback and visualisation environment.

A particularly attractive feature is the ability to synchronise a number of recordings so that you can jump from one to the corresponding point in another. There is a range of built-in visualisations such as spectrograms, again highly customisable, but an essential strength of Sonic Visualiser is its ability to support third-party plug-ins.

Offline Package Management for Ubuntu / Debian Systems - Keryx

Keryx provides a way to download software and updates for Ubuntu systems that have little or no connectivity to the Internet. Simply put Keryx on your pen drive, use it to create a new project file (which retains a copy of your software sources and other system details), then take the pen drive to a computer with a better connection. Via its Synaptic-like interface, users can then select all updates for download, plus select any other software they may want to install, complete with dependency resolution.

The most interesting part of Keryx is that you can install or upgrade the package for your Ubuntu or Debian system from another Linux or Windows system which got better Internet connection.

UI Application for create and verify md5, crc32 and other checksum - PySum

PySum is an application for calculate and verify checksums.

PySum Support:
* MD5
* CRC32
* SHA1
* SHA224
* SHA256
* SHA384
* SHA512

How to debug Shell Scripts

When things in your script don't go according to plan, you need to determine what exactly causes the script to fail. Bash provides extensive debugging features. The most common is to start up the subshell with the -x option, which will run the entire script in debug mode. Traces of each command plus its arguments are printed to standard output after the commands have been expanded but before they are executed.

Security Scanner for Debian and Ubuntu Linux Servers - Buck-security

Buck-Security is a security scanner for Debian and Ubuntu Linux. It runs a couple of important checks and helps you to harden your Linux system. This enables you to quickly overview the security status of your Linux system.

As a system administrator you often get into situations where you have to take care of a server, that has been maintained by other people before. In this situation it is useful to get an idea of the security status of the system immediately. Buck Security was designed exactly for this. It runs a few important checks and returns the results. It was desigend to be extremly easy to install, use and configure.

How to change the GRUB 2 Default Timeout and Boot Order - Ubuntu

GRUB 2 is the next generation of GNU GRUB, using version numbers 1.90 and above. GRUB 2 is a complete rewrite. The most important goal is to make GNU GRUB cleaner, safer, more robust, more portable and more powerful.

If you're already familiar with GRUB Legacy, you'll find that the GRUB 2 configuration file is similar in broad strokes, but it varies in many details. You should be aware of alternative means of configuring GRUB 2, as well.

How to speed up the booting process for Grub2 boot loader using profiling

When you boot up your machine Grub does a search for all the necessary drivers to load. This takes time. Instead of making Grub search for these drivers, the profiling actually makes Grub remember every driver necessary to work, thereby cutting down all of the driver load times.

Profiling is a way of indexing IDes required for Grub during its part of the boot process. This allows it to locate required files quicker in the subsequent boots and thus accelerate the boot process.

GNOME Gconf Registry Cleaner - Gconf Cleaner

GConf is a system of storing preferences of most of the installed applications, as well as the environment and desktop for GNOME for Linux, It is intended for user preferences; not configuration of something like Apache, or arbitrary data storage.

GConf involves a few new concepts, but no rocket science. Essentially GConf provides a preferences database, which is like a simple filesystem. The filesystem contains keys organized into a hierarchy. Each key is either a directory containing more keys, or has a value. For example, the key /apps/metacity/general/titlebar_font contains an integer value giving the size of the titlebar font for the Metacity window manager.

Speed up Internet access by using Persistent DNS caching with Pdns - Ubuntu Linux

pdnsd is a proxy DNS server with permanent caching (the cache contents are written to hard disk on exit) that is designed to cope with unreachable or down DNS servers (for example in dial-in networking).

pdns installation:
Open up the terminal Application > Accessories > Terminal and type following command:

sudo apt-get install pdnsd

Once installed the software is configured via the file /etc/pdnsd.conf.

The next thing to do is to edit the pdnsd configuration file /etc/pdnsd.conf to specify which DNS servers the cache should use for its own lookups.

How to Limit network access by user / group using iptables - Owner Match

Iptables and netfilter is a Linux kernel 2.4+ iptables administration tool. netfilter and iptables provide a Linux kernel framework for stateful and stateless packet filtering, network and port addresss translation, and other IP packet manipulation. The framework is the successor to ipchains.iptables is built on top of netfilter, the packet alteration framework for Linux 2.4.x and 2.6.x. It is a major rewrite of its predecessor ipchains, and is used to control packet filtering, Network Address Translation (masquerading, portforwarding, transparent proxying), and special effects such as packet mangling.

Owner match:
The owner match extension is used to match packets based on the identity of the process that created them. The owner can be specified as the process ID either of the user who issued the command in question, that of the group, the process, the session, or that of the command itself. The owner match only works within the OUTPUT chain, for obvious reasons: This module attempts to match various characteristics of the packet creator, for locally-generated packets. It is only valid in the OUTPUT chain, and even this some packets (such as ICMP ping responses) may have no owner, and hence never match.

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