Wednesday, November 25, 2015

Alexa Pro Certified Increase My Website Rank

In my personal view, Alexa is a standout amongst the most famous web ranking system in this decade. In spite of the way that the Alexa positioning does not reflect web traffic precisely, it is still imperative for website admins to enhance the rank. I have web that get more than 20,000 visits a day, and only got rank more than 200,000. That's maybe because Alexa rank the website by gather data from users who access the web and have Alexa Toolbar in their browser. My web visitors mostly use mobile phone.

Last month (October 2015), I tried to use their pro service (Basic Plan) to get my website certified. It need 3 days to my website certified in the Alexa dashboard, and took almost 1 month to show to public that my web is certified. In their certified metric, my web increased it rank significanly from 210,531 to 27,639.


So, my conclusion from my personal experience is: Alexa Pro can increase rank for website with more traffic but have less visitors-with-Alexa-Toolbar.

Saturday, June 27, 2015

Install Ubuntu 14.04 LTS on IBM Server x3530M4 7160 A2A

We problem installing Ubuntu 14.04 LTS on IBM Server x3530M4 7160-A2A. We also tried CentOS 6.6-x86_64 minimal without any good result. They said that the problem was in EFI BIOS, but we already update everything without result.

The installation finished, but when we restarted the server it won’t boot. Both Ubuntu and CentOS installed the UEFI in the right place. It just don’t boot. We tried to install Windows 2008 Server R2, and it works.

Then, after last time installed once again Ubuntu using same way with default steps on installation wizard, installation finisher without error. I reboot the server and put IBM Server Guide in external CD ROM then did steps to install Windows 2008 Server R2. Using wizard on IBM Server Guide, I follow steps to define the hard drive and I select default RAID, and restart. After restart, I watched TV and I forgot to insert Windows Server CD. But, voila! The Ubuntu Server boot normally. So, it seem that the IBM doesn’t detect the HDD and it recovered after I select RAID on Server Guide wizard. Lucky for us, after more than 3 weeks..

Sunday, March 1, 2015

Built Electric Quadricycle (4 Wheel Bicycle) DIY

We built the quadbike or 4 wheel bicycle with electric power. Technically, this vehicle uses a bicycle component, but the pedal been eliminated. We built this quadbike starting in February 2014, by made the framework of the body in 3abike Bandung, and followed by finishing at January 2015 in Yogyakarta by mas Wiwien Vegas who also is the owner of Mobilijo, the shop manufacturing of electric cars in Yogyakarta.

His quadbike or electric quadricycle powered by a 48V 20Ah battery and the engine is Brushless DC 48V 750 Watt and has a maximum cruising speed of 35km/h with a distance of 35km, which is sufficient for going to the office. Currently, this quadbike standby at my office headquarters as an icon for the concept of green energy.

The next following development that will be done on this 4-wheel electric bike is the addition of a capacitor to lighten the load current from the battery and add solar cell panels as roof to recharge the vehicle.

Sunday, February 8, 2015

Bing Bot SSL SNI Support

When I migrated some website to use HTTPS, I noticed that not all browsers have SNI support and my website that migrated to SSL use shared IP address, so only browsers that support SNI can access the website.

The challenge is to make sure that my website is still exists in search result on the major search engines. Google Bot already support SNI, and how about Bing Bot? To make sure that Bing Bot support SNI, I read the log of my server and I got similar with this from the log file. "Mozilla/5.0 (compatible; bingbot/2.0; +"

So, I got conclusion that Bing Bot 2.0 support SNI when crawl HTTPS website, and I checked in their search result that my HTTPS website with SNI is there.

Saturday, February 7, 2015

Full Outer Join in MySQL

In this case, I have 2 tables that need to join and show data in both tables even there is no data in one of the tables. For example, I have first table with data:


and the other table


I want to show the data like this:


By default, currently MySQL don’t support FULL OUTER JOIN. To achieve this, you can combine LEFT JOIN and RIGHT JOIN.

FROM `table1`
LEFT OUTER JOIN `t2` ON `t1`.`id` = `t2`.`id`


FROM `t1`
RIGHT OUTER JOIN `t2` ON `t1`.`id` = `t2`.`id`;

We can think of a UNION as meaning "run both of these queries, then stack the results on top of each other", with some rows will come from the first query and some from the second. UNION in MySQL will eliminate exact duplicates, so the result of the UNION only lists the same data once.

Friday, February 6, 2015

lftp Fatal error: Certificate verification: Not trusted

When I use lftp to transfer file between my Linux machine and my hosting server, I type the command in my Linux shell:

# lftp -u myuser,mypassword
cd: Fatal error: Certificate verification: Not trusted

The problem is the server certificate it not valid on the server. To override this error forever, I just created file in my home folder.

# vim .lftp/rc
set ssl:verify-certificate no

Then, I got next error from lftp console.

Access failed : 521 Data connection cannot be opened with this PROT setting.

In tne file “.lftp/rc” I added more lines with:

set ftp:ssl-force true
set ftp:ssl-protect-data true

The problem then gone, and I can transfer the data from and to server without problem.