Network virtualization issues

Just several simple things what I got in a seminar.

One of category in virtualization is 'network virtualization' which has not been completely achieved yet.

There are two issues in network virtualization, which are performance isolation and reachability isolation. The latter is supported now in several CPUs, but the former is not addressed yet especially in the area of cloud computing.

The performance virtualization is very critical issue since it can be a bottleneck of QoS in a cloud.

Service, Product, Commodity, and System

According to Mathur, if buyers are offered absolutely no differentiation on the product or the service, it really is a 'commodity'.

'Products' are goods that can be differentiated in some way, perhaps through innovation, quality or durability. But if they can't, differentiating the support or the customer service can effectively turn them into 'services'. And the best strategy is to communicate differentiation on the product and its support, and selling a 'system'.

-from 'Commodity Products: is there an alternative to selling on price?', stakeholder, 2009

A representative example of this is water business. Originally water was commodity: there was no differentiation in water business, but with some differentiated supports, it became non-commodity. If a bottle of water contains more nutrients than others, it can be called as a product since it's differentiated through innovation.

Garbage collecting when using Bitmap in Android

This article is related to the previous one, which also deals with memory leak in Android.

Today, I found a simple stupid way but useful method.

In order to release Bitmap, many articles suggest recycle(), but can be used only some activities are destroyed. If an activity is not terminated and just some of large Bitmap images are loaded, you can use

'System.gc()'

to execute garbage collector.

This is somewhat not intuitive but works well.

Preventing memory leak when using Bitmap in Android

Memory leak is very annoying when using Bitmap class while developing Android application.

There were some of solutions from websites, but they worked with some sacrifices.

(BitmapFactory.Option.inSamplesize... etc...)

I found a new article by a coincidence. This is not a brand new idea but it gives a clear way to solve the problem. I have not tried yet but it seems good. See the link below.

http://blog.pseudoblue.com/2010/08/15/android-bitmaps-and-memory-leaks/comment-page-1/#comment-190

About '\r' and '\n' in C language

'\r ' means 'carriage return' and '\n' means 'new line'.

When type writing machines were used, people were used to pull the lever of a type writer to the left after finishing one line. In this situation, the action to pull the lever to the left side was called 'carriage return'. And then we move paper to the upper side, which was called 'Line feed'.

After computer developed, it was not needed to put two commands for line processing. In this regards, people make the action as a '\n', and '\r' is just used to control command.

Bicycle

Rode for about 15 km around Silim-area last week.

Good enough for refreshing.