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SEARCH KEYWORD -- Distributed system



  Mount DD image on Linux

Yesterday, my Raspberry Pi running Arch Linux was not able to boot with error: Kernel Panic, not syncing: no init found. I spent a night on it, but could not find a working solution. The last option is easy: reinstall the system. That is really the last resort, for I do not want to re-setup everything I have done: samba server, Time Machine server, Xunlei Offline Downloader… Unable to mount the SD card The system does not boot, so I need to find a way to get into the file system to identi...

   LINUX,DD IMAGE     2014-06-24 07:49:14

  Android 4.0+ occupies quarter of Android market

Google updates its developer page about Android platform version market share. From the latest data, we can find Android 4.0 and above system occupy around 25% of all Android market. But Android 2.3 Gingerbread still occupies over 50% of Android market. From the above chart, Android 4.0 has 23.7% market share, the latest Android 4.1 JellyBean takes 1.8%, these two have 25.5% market share in total. But Android 2.3 Gingerbread alone still dominates the Android market, it takes 55.8% market share....

   Google,Android,Share     2012-10-02 19:22:19

  Check file readability in Java

File operation is quite platform dependent. Although Java is a cross platform programming language, the file operation in Java is also platform dependent. The obvious evidence is the file permission check. In Java, we can call canRead(), canWrite() and canExecutable() to check whether the program can read, write or execute the file specified. However, on Windows, when we call canRead() on a File object, we may get unexpected result. Actually, on Windows, when we call canRead() on a File object, ...

   Java,Files,Readable,Check     2013-12-05 06:10:15

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

  Google's new pirate penalty doesn't affect YouTube

Google has just announced a new policy: sites with high numbers of removal notices may appear lower in our results. However, this new policy may not affect the company's video site YouTube. In fact, they themselves clearly know that there are copyright protected contents on YouTube.According to a report published by Search Engine Land, through the "Removing Content From Google" page, users can remove content from the Google services with valid reasons, the services including Google Play, Google+...

   Google,Privacy,YouTube,Rank     2012-08-12 12:35:29

  How to enable developer mode on Huawei

As a developer, there might be some need to fake locations when developing and testing mobile apps for different countries. Lots of the times some fake GPS apps will be used and they will ask to enable mock location access on the device before allowing you to fake GPS. To achieve this, we first need to have developer mode enabled. In this post, we will show how the developer mode can be enabled and disabled on Huawei devices. Go to Settings, find About phone and open it. You should be able to se...

   ANDROID,HUAWEI,DEVELOPER MODE,DEVELOPER OPTIONS     2020-08-15 21:22:29

  Java Concurrency Basics: CountDownLatch and CyclicBarrier

CountDownLatch CountDownLatch can be used in synchronizing behavior among threads, it makes one or more threads wait for some actions in other threads to be completed. It has a property count which defines how many countDown() need to be called before other threads which called await() to be waked up.  When a thread calls CountDownLatch.await(), the thread will be blocked until the value of count becomes 0. The initial value of count can be specified when creating the CountDownLatch instanc...

   JAVA,JAVA CONCURRENCY,COUNTDOWNLATCH,CYCLICBARRIER     2018-03-25 07:02:40

  C++ for the Real-Time Web

C++? Why on Earth? C++ seems like one of the least likely languages to write a web application in. C++ is associated with complexity, both with language design and the need to manually manage memory. Programming in C++ unleashes a whole class of bugs associated with memory corruption and memory allocation. This is a trade off for giving more power to the developer along generally being much faster than equivalent programs in languages such as Python or Ruby. Real-time Web as a Use Case Making...

   C++,Web development,Real time     2012-01-30 06:00:20

  PaaS vs. SaaS: The Differences And How To Pick The Right Option

Platform as a service (PaaS) and software as a service (SaaS) are two kinds of cloud computing products that enable businesses and their clients to deliver and use various services, respectively. Before diving into the differences between the two concepts, it’s important to take a step back and understand what a cloud service really is. Cloud computing primarily refers to large storage of data, programs, and operations that are accessible via the Internet and are not stored on a user&rsquo...

   CLOUD,PAAS,SAAS     2020-04-06 06:30:32

  Why using + to concatenate string in Java loop is not a good option

String concatenation is a common operation in Java programming. It is to concatenate multiple strings into a single string. Java provides a String class which is an immutable class which means the object cannot be mutated once instantiated. Once a String object is instantiated, its properties cannot be changed anymore, so when concatenating strings, it's actually create a new String instance to store the concatenated string values. For example, below is a simple string concatenation example. Str...

   JAVA,STRING,JAVA 8     2019-01-18 22:07:12