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How To Use Apache JMeter To Perform Load Testing on a Web Server

12/11/2017 Aucun commentaire

Introduction

In this tutorial, we will go over how to use Apache JMeter to perform basic load and stress testing on your web application environment. We will show you how to use the graphical user interface to build a test plan and to run tests against a web server.

JMeter is an open source desktop Java application that is designed to load test and measure performance. It can be used to simulate loads of various scenarios and output performance data in several ways, including CSV and XML files, and graphs. Because it is 100% Java, it is available on every OS that supports Java 6 or later.

 

Prerequisites

In order to follow this tutorial, you will need to have a computer that you can run JMeter on, and a web server to load test against. Do not run these tests against your production servers unless you know they can handle the load, or you may negatively impact your server’s performance.

You may adapt the tests in this tutorial to any of your own web applications. The web server that we are testing against as an example is a 1 CPU / 512 MB VPS running WordPress on a LEMP Stack, in the NYC2 DigitalOcean Datacenter. The JMeter computer is running in the DigitalOcean office in NYC (which is related to the latency of our tests).

Please note that the JMeter test results can be skewed by a variety of factors, including the system resources (CPU and RAM) available to JMeter and the network between JMeter and the web server being tested. The size of the load that JMeter can generate without skewing the results can be increased by running the tests in the non-graphical mode or by distributing the load generation to multiple JMeter servers.  Lire la suite…

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ORC – Un réseau de stockage cloud, anonyme et décentralisé reposant sur Tor

02/11/2017 Comments off

Counterpoint Hackerspace, une bande de geeks localisée à Roswell dans l’état de Georgie aux États unis, a eu l’excellente idée de mettre au point un outil permettant de stocker sur Tor des fichiers, un peu à la manière d’un espace « cloud », mais avec tous les avantages que Tor peut apporter : anonymat, décentralisation et gestion par la communauté. Lire la suite…

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Categories: Logiciel, Sécurité, Système Tags: , ,

High Sierra Problems: How To Fix The Most Common Macos Issues

30/10/2017 Comments off

The excitement of installing a new version of macOS, especially if its a High Sierra 10.13, is only tempered by the possibility of it not working properly or not being compatible with the apps you use most.

Before you begin upgrade to MacOS make a bootable backup

If you haven’t started the process of upgrading yet, check if the Mac is compatible with macOS High Sierra and make a bootable backup. 

Do it now, before you do anything else. If things go disastrously wrong at least you’ll be able to boot from macOS’ Recovery partition and migrate all your data back to your Mac. You can use any backup tool you like – Apple obviously favours Time Machine, but you don’t have to use it. You can use, for example, Get Backup Pro, which comes with your Setapp subscription. Don’t have a Setapp subscription? Click here to sign up.

Common MacOS High Sierra Problems

While most new versions of macOS are relatively problem-free, it’s not unknown for users to have issues – particularly with a beta or .0 release. Thankfully most are easy to resolve. Here’s how to fix the most common High Sierra issues.

High Sierra Installer Won’t Download

If you’re trying to download the macOS High Sierra installer, you’ll need to have signed up to App Store. If you’ve done that, and managed to start the downloading process only for it to fail, force quit the App Store app.

  1. Press Cmd-Alt-Esc or go to the Apple menu and choose Force Quit.
  2. Select the App Store app and confirm you want to force quit.
  3. Re-launch the App Store and try downloading again.

Macos High Sierra Won’t Install

If the download completes successfully but the installation doesn’t finish, force quit the installer using the same procedure as above. 

  1. Restart your Mac
  2. Launch the App Store app and go to the Purchases tab. 
  3. Find macOS High Sierra and click Install. 

If that doesn’t work, try deleting the downloaded installer (it’s in your Applications folder) using CleanMyMac and download it again.

If you have a copy of macOS Server in your applications folder, that may be the root of the problem. Delete it and try again.

Lire la suite…

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Categories: Logiciel, Système Tags: , ,

NAS Synology : résoudre l’erreur rsync “permission denied” lors de la connexion au NAS après mise à jour du DSM

30/10/2017 Comments off

Mon NAS Synology vient de mettre à jour son firmware DSM et je constate en lançant ma sauvegarde rsync que la connexion rsync vers le NAS ne se fait plus : après saisie du mot de passe, on obtient une erreur “permission denied”.

Voici comment remédier à ce petit désagrément en deux minutes montre en main.

Problème : connexion SSH refusée

Lors de la connexion initiale, démarrée par :

rsync --ignore-existing --progress -vr --rsh='ssh -p22222' /home/backup/* root@example.com:/volume1/video

on obtient le message d’erreur suivant, après saisie du mot de passe:

Permission denied, please try again.
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(226) [sender=3.1.1]

Après vérification que les identifiants (user/password) sont bien corrects, il s’avère que la solution réside dans l’utilisation de l’argument --rsync-path afin d’expliciter le chemin de l’exécutable rsync présent sur le NAS.

Lire la suite…

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Categories: Logiciel, Système Tags: , , ,

2 awesome open source apps to share your terminal over the web

06/10/2017 Comments off

Want to share your terminal over the web for demo, learning or collaboration purpose? Try these two applications to share your terminal as a web application.

Please note that accepting input from remote clients is dangerous for most commands. When you need interaction with the TTY for some reasons, consider starting following tools with tmux or GNU Screen and run your command on it. Use following tools with trusted parties or inside VM. Let us see how to install and use gotty and ttyd on a Unix-like system.

1. gotty

GoTTY is a simple command line tool that turns your CLI tools into web applications. It is written in go programming language.

Installation

You can install gotty on macOS using the brew command:
$ brew install yudai/gotty/gotty

Sample outputs:

Updating Homebrew...
==> Tapping yudai/gotty Cloning into '/usr/local/Homebrew/Library/Taps/yudai/homebrew-gotty'...
remote: Counting objects: 5, done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 5 (delta 1), reused 2 (delta 0), pack-reused 0
Unpacking objects: 100% (5/5), done.
Tapped 1 formula (30 files, 22.7KB)
==> Installing gotty from yudai/gotty
==> Downloading https://github.com/yudai/gotty/releases/download/v1.0.1/gotty_darwin_amd64.tar.gz
==> Downloading from https://github-production-release-asset-2e65be.s3.amazonaws.com/40808571/c401bd34-7bd9-11e7-8
######################################################################## 100.0%
==> Caveats GoTTY! ==> Summary
🍺 /usr/local/Cellar/gotty/v1.0.1: 3 files, 8.2MB, built in 1 minute

Another option for Linux or Unix like system is to type the following command if you have a go language dev setup installed:

$ go get github.com/yudai/gotty

Usage

The syntax is:

gotty command
$ gotty htop

Sample outputs:

2017/09/23 22:31:19 Server is starting with command: htop
2017/09/23 22:31:19 URL: http://127.0.0.1:8080/
2017/09/23 22:31:19 URL: http://[::1]:8080/
2017/09/23 22:31:19 URL: http://[fe80::1]:8080/
2017/09/23 22:31:19 URL: http://[fe80::1c3a:3312:311b:cca4]:8080/
2017/09/23 22:31:19 URL: http://192.168.225.106:8080/
2017/09/23 22:31:19 URL: http://[fe80::6c1b:58ff:fe8a:4e6e]:8080/
2017/09/23 22:31:19 URL: http://[fe80::526a:bad6:960f:369f]:8080/
2017/09/23 22:31:19 URL: http://10.8.0.2:8080/

Fire a browser and type the url:
http://127.0.0.1:8080/
OR from another computer in your LAN/VLAN:
http://192.168.225.106:8080/

Sample outputs:

Gif 01: gotty in action

Gif 01: gotty in action


For more info and documentation see gotty home page.

2. ttyd

ttyd is a simple command-line tool for sharing terminal over the web, inspired by GoTTY. It is built on top of Libwebsockets with C for speed. Works with macOS, Linux, FreeBSD, OpenWrt/LEDE, and MS-Windows oses.

Installation

If you are using macOS, run the following brew command:
$ brew install ttyd
Sample outputs:

Viveks-MacBook-Pro:~ veryv$ brew install ttyd
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
No changes to formulae.
 
==> Installing dependencies for ttyd: json-c, libwebsockets
==> Installing ttyd dependency: json-c
==> Downloading https://homebrew.bintray.com/bottles/json-c-0.12.1.sierra.bottle.tar.gz
######################################################################## 100.0%
==> Pouring json-c-0.12.1.sierra.bottle.tar.gz
🍺  /usr/local/Cellar/json-c/0.12.1: 27 files, 156.2KB
==> Installing ttyd dependency: libwebsockets
==> Downloading https://homebrew.bintray.com/bottles/libwebsockets-2.2.1.sierra.bottle.tar.gz
######################################################################## 100.0%
==> Pouring libwebsockets-2.2.1.sierra.bottle.tar.gz
🍺  /usr/local/Cellar/libwebsockets/2.2.1: 29 files, 4.2MB
==> Installing ttyd
==> Downloading https://homebrew.bintray.com/bottles/ttyd-1.3.3.sierra.bottle.tar.gz
######################################################################## 100.0%
==> Pouring ttyd-1.3.3.sierra.bottle.tar.gz
🍺  /usr/local/Cellar/ttyd/1.3.3: 6 files, 282.6KB

If you are using a Debian/Ubuntu Linux, run:
$ sudo apt-get install -y software-properties-common
$ sudo add-apt-repository ppa:tsl0922/ttyd-dev
$ sudo apt-get update
$ sudo apt-get install ttyd

Usage

The syntax is:
$ ttyd command
$ ttyd bash

Sample outputs:

[2017/09/23 22:57:32:9322] NOTICE: ttyd 1.3.3 (libwebsockets 2.2.0)
[2017/09/23 22:57:32:9323] NOTICE: tty configuration:
[2017/09/23 22:57:32:9323] NOTICE:   start command: bash
[2017/09/23 22:57:32:9323] NOTICE:   reconnect timeout: 10s
[2017/09/23 22:57:32:9323] NOTICE:   close signal: SIGHUP (1)
[2017/09/23 22:57:32:9323] NOTICE: Initial logging level 7
[2017/09/23 22:57:32:9323] NOTICE: Libwebsockets version: 2.2.0 brew@Sierra.local-
[2017/09/23 22:57:32:9323] NOTICE: IPV6 not compiled in
[2017/09/23 22:57:32:9323] NOTICE: libev support not compiled in
[2017/09/23 22:57:32:9323] NOTICE: libuv support not compiled in
[2017/09/23 22:57:32:9324] NOTICE:  Threads: 1 each 256 fds
[2017/09/23 22:57:32:9325] NOTICE:  mem: platform fd map:  2048 bytes
[2017/09/23 22:57:32:9325] NOTICE:  Compiled with OpenSSL support
[2017/09/23 22:57:32:9325] NOTICE:  SSL disabled: no LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT
[2017/09/23 22:57:32:9326] NOTICE: Creating Vhost 'default' port 7681, 2 protocols, IPv6 off
[2017/09/23 22:57:32:9337] NOTICE:  Listening on port 7681
[2017/09/23 22:57:32:9338] NOTICE:  mem: per-conn:          568 bytes + protocol rx buf
[2017/09/23 22:57:32:9339] NOTICE:  canonical_hostname = Viveks-MacBook-Pro.local

Fire a web browser and type url:
127.0.0.1:7681
Sample session:

Gif. 02: bash-ttyd demo


For more info and docs see project home page.

 
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Categories: Logiciel, Système Tags: ,

macOS High Sierra Supplemental Update Released for Mac Users

06/10/2017 Comments off

Apple has released the first supplemental update to macOS High Sierra 10.13, complete with bug fixes, improvements, and security fixes.

General release notes accompanying the supplemental update suggests the release includes improvements to stability, reliability, and security. Specifically, the update is said to “improve installer robustness” (it is unclear if this addresses the issue where some users are unable to download a complete macOS High Sierra installer without third party utility assistance), includes a fix for cursor graphics bugs when using Adobe InDesign, and resolves and issue with Mail app was unable to delete email from Yahoo accounts. Additionally, the update includes a security fix to address a problem where Disk Utility could be used to reveal the password of an encrypted AFPS volume, and the update also resolves a security bug relating to Keychain passwords. Complete security update release notes are below for those interested. The supplemental update is recommended for all macOS High Sierra users to install.

Mac users running macOS 10.13 High Sierra can find the update available to download and install now in the Mac App Store Updates section. The update is labeled as “macOS High Sierra 10.13 Supplemental Update”.

Note the supplemental update is separate from the beta versions of 10.13.1 currently under the beta testing programs.

Always back up a Mac before installing any system software update, including smaller bug fix updates like this macOS High Sierra Supplemental Update.

The complete security related supplemental update release notes are as follows:

macOS High Sierra 10.13 Supplemental Update
Released October 5, 2017
StorageKit
Available for: macOS High Sierra 10.13
Impact: A local attacker may gain access to an encrypted APFS volume
Description: If a hint was set in Disk Utility when creating an APFS encrypted volume, the password was stored as the hint. This was addressed by clearing hint storage if the hint was the password, and by improving the logic for storing hints.
CVE-2017-7149: Matheus Mariano of Leet Tech
Security
Available for: macOS High Sierra 10.13
Impact: A malicious application can extract keychain passwords
Description: A method existed for applications to bypass the keychain access prompt with a synthetic click. This was addressed by requiring the user password when prompting for keychain access.
CVE-2017-7150: Patrick Wardle of Synack
New downloads of macOS High Sierra 10.13 include the security content of the macOS High Sierra 10.13 Supplemental Update.

Separately, iPhone and iPad users can find iOS 11.0.2 available as an update, which also includes various bug fixes for that system software release, and watchOS 4.0.1 for Apple Watch is out as well.

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Categories: Constructeur, Logiciel Tags: ,

How to Downgrade iOS 11 to iOS 10.3.3 on iPhone and iPad

06/10/2017 Comments off

Don’t like iOS 11 on your iPhone or iPad? You can downgrade to iOS 10.3.3 if you act quickly. Maybe you don’t like the update, maybe you find iOS 11 battery life to be poor, or app compatibility to be a problem, or perhaps you think the performance is subpar. Whatever the reason, you can easily downgrade iOS 11 if you need to, but the ability to downgrade is only available for a limited time while Apple continues to sign the prior operating system release of iOS 10.3.3.

We’ll walk through how you can downgrade iOS 11 back to iOS 10 on an iPhone or iPad.

This guide requires iTunes and a computer, internet access, an iOS 10.3.3 ISPW file, and a USB cable. There is no way to downgrade iOS 11 without iTunes and a computer.

Important note: downgrading iOS 11 to iOS 10.3.3 can cause data loss, including the removal of important data or everything on your iPhone or iPad. Thus it is critical to have a backup that is compatible with iOS 10 available before downgrading (one should have been made prior to updating to iOS 11 in the first place), this is because iOS 11 backups are not compatible with iOS 10 or other prior releases. If you only have a backup for iOS 11, then downgrading to iOS 10 may require you to update again to iOS 11 in order to restore from that iOS 11 backup. If you don’t know what you are doing and do not have adequate backups, do not attempt to downgrade or you may experience permanent data loss on the iPhone or iPad.

We’ll cover two ways to downgrade, a simple way that should work for most users, and an approach that requires Recovery Mode if the first downgrade method fails.

Lire la suite…

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How to Download a Full macOS High Sierra Installer App

04/10/2017 Comments off

Many Mac users who are attempting to download macOS High Sierra from the Mac App Store will find that a small 19 MB version of “Install macOS High Sierra.app” downloads to the /Applications folder of the target Mac, rather than the complete 5.2 GB Installer application for macOS High Sierra. This is annoying because it prevents a single download from being used on multiple computers, plus the small installer requires an internet connection during usage to download the rest of the High Sierra update files. Additionally, the tiny 19 MB incomplete installer prevents users from being able to create a macOS High Sierra USB installer drive or other custom update options available through the command line, like skipping the APFS update.

This tutorial will show you a workaround trick that allows Mac users to download the full macOS High Sierra “Install macOS High Sierra.app” file at 5.2 GB with the complete installer tool set and all dmg files and associated Install macOS High Sierra.app/Contents/Resources/ tools, rather than the tiny incomplete truncated installer at 19 MB.

How to Download the Full “Install macOS High Sierra.app” Application

Warning: this method relies on a third party tool from an unverified third party source, if you are not comfortable with using unvetted and unverified software, and if you do not understand the risks associated with using potentially dubious software, do not follow this process. This is for advanced users only.

    1. Go to dosdude1.com here and download the High Sierra patcher application*
    2. Launch “MacOS High Sierra Patcher” and ignore everything about patching, instead pull down the “Tools” menu and choose “Download MacOS High Sierra”

    1. Confirm that you want to download the complete macOS High Sierra install application, and then point it to a location to save on the local hard drive

    1. The patcher app will notify you when the download is complete, when it is done downloading quit out of the patcher app

    1. Locate the “Install macOS High Sierra.app” file you downloaded, it will be the complete installer application with the full Contents/Resources/ toolkit available

* The “macOS High Sierra Patcher” application is intended for those with unsupported Macs and Hackintosh users, but any Mac user can use the app to be able to download the complete installer file from Apple servers. The source of this patcher application is a MacRumors Forums

You can confirm that you have the complete Install macOS High Sierra.app application by getting info on the file, the complete installer should be around 5.2 GB rather than the tiny 19 MB incomplete installer that requires additional downloads.

The complete macOS High Sierra installer downloaded

Why do some users get a small incomplete version of macOS High Sierra installer from the App Store?

This is not yet known, but it happens with the final version of macOS High Sierra installer as well as with some of the beta versions.

It is unclear why some users will get a 19MB version of “Install macOS High Sierra.app” when downloaded from the App Store, while others users will get the complete 5.2GB version of “Install macOS High Sierra.app” when downloading from the App Store. Interestingly, once a user ends up with the 19 MB version of the incomplete installer, that seems to be the only thing that will download for that user regardless of how many times the incomplete installer app is deleted and re downloaded.

Incomplete macOS High Sierra installer

The installer size and completeness inconsistency appears random, and has no relation to disk space, beta enrollment, software catalog, and other theories seem to be incorrect as well.

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How to Disable or Enable Auto-Brightness in iOS 11 for iPhone and iPad

04/10/2017 Comments off

Auto-Brightness is a screen setting on the iPhone and iPad which causes the device to automatically adjust the display brightness depending on ambient lighting conditions. For example, if you’re outdoors or in bright lighting, the screen would adjust to be brighter so that it is more visible, and if you’re in a dim room or outdoors at night, the screen would adjust to lower the brightness so that the screen isn’t as glaringly bright. Auto-brightness in iOS also can improve battery life by adjusting the brightness of the iPhone or iPad display down as the ambient lighting permits.

Lire la suite…

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Categories: Constructeur, Logiciel Tags: ,

How to Migrate a Web Server Running Apache, MySQL, WordPress and Drupal

24/02/2017 Comments off

Well folks its time that my old home hosted server is retired. Which means I have to migrate all of my 5 websites to a new server. Thanks to the way apache, MySQL WordPress and Drupal work, its easy.

1. Copy Apache Config Files

# ssh username@oldserver
# scp /etc/apache2/sites-available/ user@newserver:/etc/apache2/sites-available/

This will copy all the apache config files over to the new server. Now enable all the sites you copied by creating a symbolic link for each .config file you copied in sites-enabled.

# ln -s /etc/apache2/sites-available/yourwebsite.com.conf /etc/apache2/sites-enabled/yourwebsite.com.conf

or use the command a2ensite which does the same thing for you

# a2ensite yourwebsite.com

Restart apache for the changes to take effect.

# /etc/init.d/apache2 restart

2. Copy Your Websites

# scp -r /var/www/ username@newserver:/var/www

Default WordPress and Drupal installs are just files and we have now copied them across. However all the content, comments etc are stored within MySQL so lets migrate that now.

3. Migrate MySQL

Start by being logged into the old server.

# mysqldump --all-databases -u root -p > backup.sql
# scp backup.sql username@newserver:/home/username/
# ssh username@newserver
# mysql -u root -p < backup.sql

What we did here was use mysqldump to script every database and its contents into several sql commands. Then we copied them to the new server and piped them into the new sql server. All our databases, users and table contents have been imported. Magic.

4. DNS Migration

Now all you need to do is reconfigure your DNS servers to point to the new IP address. Chances are your not hosting your own DNS server so you will have to update them using your provider’s web interface. A word of advice though, create a new entry like test.yourdomain.com and point it to the new server first to make sure everything works.

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