Friday, May 29, 2009

What's up? It's almost June 2009...

Yikes, it's been around 2 months since I made a target post for March 2009. But well, it's just a target ;)

But really, I'm having a hard time coping up with blog post duties and doing useful stuffs. I would want to document what I do but I don't want to spend too much time documenting it....so yes, I'm still documenting techie stuffs and what I think is useful for tech person but in a much simplified and easier form.

I'm most active in delicious.com(bookmarking and tagging sites) and twitter.com(as I can just fire up my terminal and tweet in less than a minute).

If you are on friendfeed, you can subscribe to all my posts on twitter and delicious.

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Sunday, March 1, 2009

Liar vs Truthful Mail Server

Once upon a time, when spam was not yet an "in thing", mail servers where all truthful. A mail server that sends an email to another for a non-existing address always receives a notice from its peer that says "Sorry buddy, I can't find it in my address list." Years later, the demons(spammers) found out about sending junk mails or spam. So, the IT gods(email admin) brainstormed on how to contain the inbox chaos.

Many ideas where submitted but only two suggestions emerged with the most number of supporters:
A. Accept all mails but throw away those destined for a non-existing inbox
B. Still send the "mail not found error" and wait for the spammers to change heart.

Both proposals have valid points. Proposal A supporters contends that they should never make the demon's job easier by telling them which address exist on a mail server and which one does not. Proposal B supporters though points out that it's against the mail server standard not to reply appropriately.

The two groups where not able to come to terms and so, we have today mail servers that don't tell the truth.

So, how do you know which type of mail server it is that you're dealing with? It's fairly easy. Using some of the tools online that checks for mail server responses, like what's in my email checker bookmarks:

  • Check how the mail server responds to a random email address such as "asdfa3q2xcy53c323das4yux@buggedtech.com" or asdf3s6ydq34xy7wec23572@buggedtech.com (please replace buggedtech.com with the domain name of the email you are checking, the one after the @)

  • If the mail server responds with something like "email address ok" to random email addresses you used in #1, then, that's a liar mail server. Otherwise, it's truthful.

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Target posts for March 2009

Since starting this blog, I only managed to have a handful of post but with several drafts. Rarely do I have readers but who will be interested in tracking my posts if I don't have new post to offer them? But well, I haven't committed to posting every now and then.

I created this blog as a personal space plus and an extension of my professional stuffs. Hopefully by end of March, I will be able add relevant posts like:

* Liar vs Truthful Mail Server - Explain the 2 types of mail servers, a useful info in checking if an email address exist.
* Checking Existence of Email Address - I consistently received questions from my colleagues if this and that email address exist or why they received a bounce message and what it means.

I'm targetting 2 posts each month. I know, it's a very low expectation but I don't write as fast as I could think. But even with 2 per month, I will have added 20 by end of 2009. Not bad, specially if it's quality post and not just a summary of other's post.

Friday, February 13, 2009

Redirect a bunch of URL to a single URL in Apache

I recently faced a situation wherein I have to permanently redirect a list of URLs to a single URL. I'm used to doing it for 1 to 1 redirects(1 url to another) but this is the first time I did it for a lot of URL.

Example:
http://www.example.com/oldschool/index.php?i=1
http://www.example.com/oldschool/index.cfm?i=55
http://www.example.com/oldschool/SchoolOfRock.html
http://www.example.com/oldschool/School-of-Knocks.htm

will need to be redirected to:
http://www.example.com/university

The solution? Use the RedirectMatch directive in Apache
It's so easy to use. Use the syntax:

RedirectMatch [status] regex URL


where status is 301(permanent redirect) or if not used will 302(temporary redirect) which can be used in you Apache's server config, virtual host, directory or .htaccess context.

In the above example, the exact RedirectMatch is:

RedirectMatch 301 ^/oldschool/(.*) http://www.example.com/university

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Friday, January 30, 2009

EuroDNS Domain Promo till March 1, 2009

I'm a subscriber of EuroDNS newsletter and I'm glad to inform all of you that they are having a monthly promo that will be valid till March 1st this year.

Promo Code:
8COM09 ==> 8 Euros for .com domains
9NET09 ==> 9.99 Euros for .net domains


Hurry, search for your dream .com and .net domains in EuroDNS' website at http://www.eurodns.com.

Enjoy folks :)

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Tuesday, October 28, 2008

Microsoft embraces AMQP open middleware standard

Excerpt from InternOpNews.com

"What is AMQP, and why should anybody care whether Microsoft adopts it? Well, I’ve already blogged at considerable length about where AMQP comes from and how it works, so I won’t rehash all that here. Suffice it is to say that AMQP is to high-value, reliable business messaging what SMTP is to e-mail. The proprietary message oriented middleware (MOM) products on the market today like IBM’s MQ or Tibco’s Rendezvous fulfill the same function as AMQP. But they operate exclusively in single-vendor fashion and utterly fail to interoperate with each other. They are also – perhaps not by coincidence – burdensomely expensive. As a result their use is mostly limited to wealthy organizations such as Wall Street banks (at least the ones who are still in business) that need to exchange huge volumes of business messages very reliably and very quickly. But AMQP’s supporters feel the market for such reliable messaging could be much larger if a less expensive and truly open solution became available"


Read more on InternOpNews.com

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Friday, October 24, 2008

Twitter from Command Line

You know about twitter right? If you love using it, you may be pleased that you can do it in several ways including the command line. Yes, from the CLI.

Just follow this simple steps from Dave Taylor's post in LinuxJournal.com

Happy Twittering!

Saturday, September 20, 2008

Your work shift is up so DON'T touch the code!

I'm not advocating going home seconds after your work shift ends. Rather, I just want to rehash the proven rule that you should never touch the code if you can help it because the probability that it will break is so high when you're in the "go to bed" mood. Just do the changes the following work day when you're sure to have a fresh mind.

Various examples can be cited but the experience I had several days ago is a concrete one. To give you a background, I work in an internet-based company -- an experiencial travel directory with the official designation as an SEO. Our current websites are edited "real time" in our development server and then transferred to production server via ftp. Now, seconds before my work shift ended, I suddenly realized that I can still insert a major keyword in our main search pages. I got so excited coz months ago I was resigned into the idea that there's no more room for additional key phrases in the main search page.

Not wanting to loose the excitement, I fired up the terminal application and connected to production server via ssh. I was so confident that nothing will go wrong coz I will simply add the major keyword to the search page and I know very well that the part I'm about to edit is a static text and hence a no brainer. The first few directories' search pages I edited went well as expected. It was 2:30 AM and I was already planning to defer doing the changes for the following day. However, I decided to edit one more before I can call it a day. I made the edit, flushed the web caching system, then refreshed the browser for one last look....BANG! The search page has an error. I panicked a bit knowing that this directory has the greatest traffic in all our websites. I tried finding the error stated but I can't seem to find it.

For about 20 minutes, the search page was broken. I tried recalling and validating what I did but still what I can remember is that I simply added the keyword phrase so my brain was insisting that it's not the source of the error. Programmers were no longer around and besides, it was already 3:00 AM so I don't want to disrupt their rest. Left with no choice, I had to fix it myself...a punishment for breaking the "rule". Good thing the other pages where not affected, including the "searchtext"1.

With the searchtext still up, I had to redirect the main search page to it so that I could fix the page without discouraging tens of thousands of visitors that's currently using the directory. Also, the redirect has to be "temporary" so as not to affect the crawling of the page by Google and other search engines. I preferred doing the redirect through it's apache virtual host configuration(refer to Figure 1) but I could have done it via the coldfusion language(refer to Figure 2):


Figure 1. The apache vhost configuration



Figure 2. Equivalent configuration


With the main search page redirected to the searchtext, I now had the time to fix the code. Not all visitors may like the way the current search page is formatted but it's better than having a search page and be greeted with error.


notes:
1 a page that is somewhat like our search page but lists all the options a user can choose with the dropdown menus in the searh page. This is mainly for search engine crawlers but is still usable by humans.

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Sunday, September 14, 2008

Quick Hack: ssh connection over a slow internet

Ever experienced being connected to a remote server via ssh and your terminal freezed due to inactivity? That happened to me several times and I will be a liar if I say I liked it.

Fortunately, I found out about "top", a *nix command that it intended to show the top processes in the machine you're logged on to. This same command is what I use as a quick fix/hack to the terminal freeze problem I have.

Freezes happen because connection to the remote server has been idle for some time and the remote server thinks you are not anymore interested in the current session that's why it decided to disconnect you...hence the freeze. To let the remote machine know that "I will be back please hold on", just use "top".

I still experienced some instances that my session was disconnected even with "top"(I think 1/100) but mostly, this short hack worked.

Try it...

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Smartbro experience...including making it work for Ubuntu Linux!

In my hometown(Alangalang, Leyte), internet is not yet that widespread. We do have some internet cafes but it's situated in the poblaction. I live in a barangay far from the poblacion and telcos says that as of the moment, they can't yet service our barangay although a phone line is already possible. Then I heard of SmartBro. But then again, they would tell me it's not yet offered for Alangalang residents. Fortunately, the SmartBro Prepaid version came shortly so I didn't think twice in getting one.

The downside of getting the prepaid was that it has a very slow internet connection...even slower than a dial-up line(imagine a connection speed of mostly 25% of 64kbps!). But I guess that was the very reason of Smart for not selling to me yet as they know I will only be frustrated with the connection speed.

Smart signal is not a problem here as we could get full bars. With the Smartbro prepaid kit, I could get 3 bars at most but internet speed is not that good yet(as I just mentioned). I admit that I got frustrated but I still understand Smart as it's not yet economical for them to allocate a larger bandwidth to an area that seldom has SmartBro. The only thing that I think Smart should need to improve on is the consistency of internet connectivity. I experience once a week that I can't browse websites, not even Google using its ip address(to bypass DNS) and image loading in my browser turned-off(which is not a factor as the only image in its homepage is its logo). You can't say that I don't have load as I'm sure it's not empty as I just reloaded it. Anyway, I hope Smart will improve in this aspect.

Enough of the introduction we'll go back to the main topic: Smarbro working in Ubuntu Linux(Hardy Heron 8.04). This is nothing new actually. Another IT Geek(Arpee Ong) has posted this in his own blog but there are comments that say's they can't make it work. His distro was Fedora but I tell you, I never made any changes to his instructions:
1. Created a udev definition for the zte mf622 hsdpa modem
2. Made a smarbro.conf configuration file
3. Run the config with wvdial (used "sudo" of course as wvdial is owned by root)

Another thing that I always liked doing is add some DNS in my /etc/resolv.conf, even if Smarbro provides their own, and I use OpenDNS for this purpose (208.67.222.222 and 208.67.220.220) since it sometimes resolves domain name to ip faster aside from the fact that porn/phising and other violent side of the internet is mostly filtered.

Lastly, I used Squid as my proxy. Install it via apt-get or Synaptic Package Manager. Give it a "visible_hostname" and put localhost:3128 in your browser and you're ready to go. Browsing speed may not be immediately felt but as squid gathers more data, it will significantly help specially in your commonly browsed websites.

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