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4 Layers of AWS Architecture a Quick Answer

I have collected real interview questions on AWS key architecture components. Those are S3, EC2, SQS, and SimpleDB. AWS is one of the most popular skills in the area of Cloud computing. Many companies are recruiting software developers to work on cloud computing.

AWS Key Architecture Components AWS is the top cloud platform. The knowledge of this helpful to learn other cloud platforms. Below are the questions asked in interviews recently.
What are the components involved in AWS?Amazon S3.With this, one can retrieve the key information which is occupied in creating cloud structural design, and the amount of produced information also can be stored in this component that is the consequence of the key specified.Amazon EC2. Helpful to run a large distributed system on the Hadoop cluster. Automatic parallelization and job scheduling can be achieved by this component.Amazon SQS. This component acts as a mediator between different controllers. Also worn for cushioning requirements those are obt…

Hadoop: How to find which file is healthy

Hadoop provides file system health check utility which is called "fsck". Basically, it checks the health of all the files under a path It also checks the health of all the files under the '/'(root).
  • BIN/HADOOP fsck / - It checks the health of all the files
  • BIN/HADOOP fsck /test/ - It checks the health of files under the path
By default fsck utility cannot do anything for under replicated blocks and over replicated blocks. Hadoop itself heal the blocks.
Healthy file checking ides

 How to find which file is healthy

  • It prints out dot for each healthy file
  • It will print a message for each file, if it is not healthy, also for under replicated blocks, over replicated blocks, mis-replicated blocks, and corrupted blocks.
  • By default fsck utility cannot do anything for under replicated blocks and over replicated blocks. Hadoop itself heal the blocks.

How to delete corrupted blocks

  • BIN/HADOOP fsck -delete block-names
  • It will delete all corrupted blocks
  • BIN/HADOOP fsck -move block-names
  • It will move corrupted blocks to /lost directory
  • Other options we can use with fsck:
    • files
    • blocks
    • locations

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