Sunday, October 2, 2016

Bootable Windows with Ubuntu

Create bootable windows with ubuntu is an alternative if you do not have an cd-rom to install laptop. I apply this experience when getting a new asus laptop and want to install Windows using a usb flash because it does not have an cd-rom. It is just like using unetbootin in linux distro. The following sequence of creating a bootable flash windows using ubuntu: 1. Open a terminal and type the command : a. sudo add-apt-repository ppa:colingille/freshlight
b. sudo apt-get update
c. sudo apt-get install winusb
2. open winusb
3. Prepare iso windows and flash that will be used for bootable. after opening WinUSB, click from a disk image (.iso) and navigate to the storage directory iso windows. Make sure the flash has been detected on your computer.
4. WinUSB process will use some time
5. If completed then we will have a bootable flash drive that is ready for install windows in laptops that do not have a cd-rom.
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Tuesday, September 13, 2016

Virtual Statistics Laboratory

Starting from a less popular software-based non-commercial one R among practitioners of statistics, Statistics Virtual Laboratory designed with toolkits based R-shiny, to create a web-GUI interfaces. With the aim of using visualization R without having to master the language R, because communication with the user can be done through a web friendly. Professor of Statistics Prof. I Made Tirta create web content form of a tutorial / handouts / lecture notes electronically simulated illustrations presented directly by R. document that is therein, also includes mathematical notation correctly through the ability LaTeX on MathJax. By using server-based Ubuntu Server and apply the r-shiny therein made interactive web makes it not only learn but also to give it a try. As I wrote earlier about building R-Shiny local computer, Virtual Laboratory Statistics is a continuation and development of the HTML for ease of application. Added also the application of Latex and MathJax through the Java language. Visitors can learn about a wide range of simulation are: Probability Freq, Mean Distributions and Normal Distribution. Demo also many show started Basic Statistics, Simple Regression, Cluster Analysis to RGraphics.
Statistics Virtual Laboratory glance similar to R-cloud that has been there, but the advantage is visitors no longer need to learn to use the language R. All the facilities have been provided and have been programmed in it are also still using the R language is always complete with the package - a package terupdatenya , As we used to know and use R-Commander, this is more interactive and web-based major has. Where and whenever can be used easily and learning becomes simple.
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Monday, December 29, 2014

Joomla jos_session problem

The use of CMS in the web world are now widely used. Ease of managing the content of the web and many features provided, greatly helps web designer to create beautiful view of the web. Likewise with me were very keen to use the CMS. In case this is Joomla is arguably the most popular of several existing CMS. Some time ago there was a bit of a problem arising from the web that I manage. Error message is like this:
This is because jos_session is used to manage user sessions, so it is written to frequently. The most common cause of a corrupted table is a failed write. When the server runs out of resources, it is usually in the middle of a write, This the corrupt jos_session table.
After looking at several forums references and do some experiments there is a solution that might help to resolve the problem of the session. The first solution is to delete and re-create jos_session table using SQL commands:
DROP TABLE IF EXISTS `jos_session`;
CREATE TABLE IF NOT EXISTS `jos_session` ( `username` varchar (150) default '', `time` varchar (14) default '', `session_id` varchar (200) NOT NULL default '0', `guest` tinyint (4) default '1', userid` `int (11) default '0', `usertype` varchar (50) default '', `gid` tinyint (3) unsigned NOT NULL default '0', `client_id` tinyint (3) unsigned NOT NULL default '0', `data` LONGTEXT, PRIMARY KEY (`session_id` (64)), KEY `whosonline` (guest``, `usertype`), KEY `userid` (` userid`), KEY `time` (` time`) ) ENGINE = MyISAM DEFAULT charset = utf8;
The second solution to fix jos_session table using phpmyadmin: Find Joomla database in phpmyadmin then find table jos_session, repair that table
The third solution by modifying existing files in the directory joomla itself. For this section there are some files that are modified to overcome the problem session:
1. Edit the file libraries / joomla / database / table / session.php
function insert ($ sessionId, $ ClientID)
{ $ url = 'http: //'.$_SERVER [' SERVER_NAME ']. $ _ SERVER [' REQUEST_URI '];
$ this-> session_id = $ sessionId; $ this-> client_id = $ ClientID; $ this-> time = time ();
if ($ this-> guest! = 1 || stristr ($ url, '/ administrator')) $ ret = $ this -> _ db-> insertObject ($ this -> _ tbl, $ this, 'session_id');
if (! $ ret && $ this-> guest! = 1) { $ this-> setError (strtolower (get_class ($ this)). "::". JText :: _ ('store failed'). "
". $ this -> _ db-> stderr ()); return false; } else { return true; } }
 2. Edit the file /index.php
/ ** * CREATE THE APPLICATION * * NOTE: * / $ mainframe = & JFactory :: getApplication ('site');
 Change to:
$ mainframe = & JFactory :: getApplication ('site', array ('session' => false));
The next solution is to change the configuration in Joomla. Joomla by default tracks jos_session session data in the table, as I see you've figured out. However, you can disable this by going Easily to your admin panel - Global Configuration - System - Session Settings and change the session handler from "database" to "None".

And the last is the patience and prayer to overcome the problem.
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Wednesday, September 3, 2014

MySQL: Too Many Connection Error

It has been very much used MySQL since introduced around the year 2005, and this leads to a real DBMS Engine which allows the direction of the Enterprise. More economical than the use of another engine such as MS SQL or Oracle. But there are to watch out for with the economic value, is the issue of too many connection, many servers that have a very high visitor is having trouble. And I feel it when going on a website that I have ever manage at FMIPA Universitas Jember
Too Many Connection occurs because of some problems like this: too many connections that occur simultaneously, often experienced by these sites that weve crowded. packet flooding defect occurs to the port that MySQL is used, this can be tested by doing a telnet to 3306 too many connections are already obsolete, but not in the release or in-free
For the first cause, which occurs because the force is due to conditions that occur simultaneous connections. To solve this problem is to tweak the mysql configuration file (my.ini or my.cnf) and increase the value of the max_connections variable. Default variable values ​​100 For websites that crowded, maybe less default settings. Or it could be another way to dispose of or give a # at the max_connections variable. 

For the second cause, there are many defects in the pool MySQL package, how to fix this is to do mysqladmin flush using the tools. make a batch-script that contents mysqladmin flush-hosts then attach a handler in the web server or on a desktop program (adjust with the environment) if you find an error in MySQL engines with error code SQLSTATE = 08S01 (for server-related error bad packet) or 46000 (to a server error relating to that connection) 

For the third cause, too many connections that are already obsolete, but not in the release or in the free, this is a coding issue. Code that is not good, it will leave a lot of junk in the cache server. For the coder, may know how to connect to the DBMS, whether by way of persistent-connection or non-persistent. What is gained if you have too many connection, he replied restart the server. But if we understand the 3 terms above may be a bit inevitable. I HOPE
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