Tuesday, October 4, 2011

Too many MySql connections - Magento

There was a weird problem I faced with Magento on Bluehost server. The site keeps throwing error saying there are too many connections with MySql database with a single user. On contacting the hosting provider they said they allow maximum of 15 concurrent connections for a single DB user. while 15 is not a good number by any means, it's not very bad for a newly started website either. It's less probable that 15 users are attempting connection to the DB at a moment. But the error log consistently showed me this error and it was far too often.

I tried to look at the phpinof.php file to see if there is anything abnormal related to the MySql settings. Yes, there was a surprise for me. The persistent connection was set to ON in that file. Apparently this had to be THE problem. When I checked in the php.ini file there was no such setting so I assumed that it comes from the default php.ini settings. So I set it to off in my PHP.ini file. Since then, I have not faced this problem.

Although this problem is solved for now, I'm sure it is going to come back at some point of time as 15 concurrent connection is not an adequate number. But it gives me a breath for the moment!

Wednesday, September 28, 2011

HTML 5 with Sencha and Adobe Edge

I'm venturing with HTML 5 these days. Currently I'm studying Sencha and Adobe Edge. These two are Flash like softwares which allow you to create animation through GUI program. Basically what you do is just creating number of frames that would combine up eventually to form an animation. Pretty much like flash. I'm really excited about this stuff. I'll keep posting my experiences. Thanks.

The reference links

Thursday, September 22, 2011

Flash Vs HTML 5

It really amuses me when people say that HTML 5 is the direct replacement of Flash. Internet chatters have started shouting like "HTML 5 is a miracle", "Who wants flash", "Flash is dead" and what not. So what really is this all about? Are they true? I'm sure anybody who has slightest of experience with Javascript programming will part his way from this bandwagon.

What is HTML 5 animation?

J Well, it’s just Javascript maneuvering. HTML has come up with a new tag element called “canvas” that is meant to be the medium of animation. Javascript is used to animate this canvas.

Can we do in HTML 5 whatever we can in Flash?

If we take it up as a separate project and decide to emulate whatever Flash can do then it could be possible on many cases. But it’s not feasible. Flash with all its powerful tools and utilities is a far superior and rapid option to create animation.

Why it is so hard?

Because you have to code it. Flash and HTML are meant for different purposes and have different philosophy. Flash does everything for you automatically while in HTML you have to actually code it. In most of the sites nowadays we see a banner rotator. Do they code it? No. They use JQuery. JQuery is a separate Javascript project which is built upon reams of coding over the years. But JQuery also has its own limitation. Even after all these years, JQuery has a limited set of pre-coded animations (that too basic ones) available. And here we are talking about replacing the boundless power of Flash. Because of this, barring some “prototype” examples we see for HTML 5 on net, it is not used for REAL animation anywhere.

So what's in the future?

Until someone comes up with a software that writes all the javascript automatically from a graphical interface for HTML 5 (just as Flash does it) it is going to remain an over hyped concept. The iPad/iPhone programmers will continue to use video files as the flash replacement.

In short, if you are not a web programmer, you will find the Flash Vs HTML 5 conversation interesting. Otherwise, you will just laugh at it and continue doing what you have been doing for years.

Monday, April 18, 2011

SEO For Google


For some unknown reasons people do believe that as a website gets older it gets higher rank on Google SE. Because of this belief people start believing that just because more number of users are using the site, it gets upper rank. While this is true but the reasoning behind this is not correct. If it was like that, then all the web admins would do nothing but keep refreshing the page all the time!

I wonder, why the believers of this theory are not confronted by the question "how do Google know that how many people are using my site?". Think about it.

The most essential thing is the content of the site and the number of people who are interested in reading/searching that content on Internet. What happens is, when you search for something on the web and find something of your interest, you will click on that link. Google records your all the clicks against the search term you entered. Now as more and more people search for that term and start clicking on your link, Google ranks your site higher, simply because you have the content which interests the users. Simple!

Now, Google has introduced the +1 function for each search. So when people search for a keyword and find your site interesting, people will do +1. Need I say that this would boost your SEO greatly? ... :)

So here is the rule. it really doesn't matter how old your site is. What matters is your content which would interest people. Smart way, isn't it?

Thursday, January 20, 2011

When to use Stored Procedures?


Before some days, I talked about system calls. While including a file to the script is a system call, connecting to database server is also a system call. So obviously it will make the site slow.

There is a popular belief that SPs are helpful in getting faster database performance. But very few know why. Most people believe that it is because the code is pre-compiled. This is not true. The fact that you can pass variables to a SP, it has to be dynamic and cannot be pre-compiled. So. is SP really faster as they say? The answer is Yes and No. A SP is fast is it is used for appropriate reason. Otherwise there is no difference. So what is the right use of SP?

As I said in the beginning, all the database calls are system calls. So the site becomes slow when you fire more and more queries on the database. In most occasions this is inevitable. But in some cases there is an alternative. Sometimes when you are doing database operations, you fire a query to get some result. Now based on this result you have to fire another query to get some more result. Also, this process may not be possible joins. So in this case, you would be firing two system calls. So instead of firing two queries, just create a stored procedure that would fetch the first value from database, do the necessarily operation, fire the next query and give you the result as the output. Thus you make only one system call. The fact that the stored procedure is the part of the database engine, it would not make extra system call when it is firing a query. So here you go, you get two query worth output with only one system call. so it is now faster!

Hope I made sense here.

Monday, January 10, 2011

What makes your site slow the most? System Calls.


Today I will talk about a highly discussed topic. But I'm not going to talk about the usual reasons given for this. I'm going to talk about a much unknown and and un-talked factor. The system calls.

Believe it or not, the most time taking process in site execution is the "System Calls". Whenever you "require" or "include" a file, it makes a system call on server to include that file in your script. So it depends upon how many files you are including in your script. In today's world of MVCs, there is literally no limit of the files you include. This is not to take away the fact that MVCs are marvelous platforms to build any web application (for many reasons) but they do have impact on the speed. The reason behind Magento being slow is much more this.

If you want a phenomenal speed, write the whole code on a single file! I know it sounds ridiculous but the applications who have a HUGE amount of load everyday, do exactly this! Example SourceForge and GForge. They have millions of lines of code in a single file.

However, MVCs do have the work around for this problem. They do caching. Using caching they evade this short coming greatly. And we all know the power of MVCs.

So guys, keep using MVCs for all the reasons. But it's just that when you create a SourceForge or GForge, avoid them!