What is Software Architecture?

* Architecture Is a Set of Software Structures 3 categories of architectural structures:                                              ...

REST architectural style describes six constraints applied to architecture

  1. Uniform Interface  Individual resources are identified using URLS. The resources (database) are themselves different from the representation (XML, JSON, HTML) sent to the client. The client can manipulate the resource through the representations provided they have the permissions. Each...

Web API Best Practices

  Considering Top 10 Status 200 – OK – Everything is working201 – OK – New resource has been created204 – OK – The resource was successfully deleted 304 – Not Modified – The client can use cached data 400 – Bad Request – The request was invalid or cannot be served. The exact error should be explained in the error payload. E.g. „The JSON is not valid“401 – Unauthorized – The request requires...

Explain Elastic Block Storage? What type of performance can you expect? How do you back it up? How do you improve performance?

 How do you improve performance? EBS is a virtualized SAN or storage area network.  That means it is RAID storage to start with so it’s redundant and fault tolerant.  If disks die in that RAID you don’t lose data.  Great!  It is also virtualized, so you can provision and allocate...

What is S3? What is it used for? Should encryption be used?

S3 stands for Simple Storage Service.  You can think of it like ftp storage, where you can move files to and from there, but not mount it like a filesystem.  AWS automatically puts your snapshots there, as well as AMIs there.  Encryption should be considered for sensitive data, as S3...

What is an AMI? How do I build one?

AMI stands for Amazon Machine Image.  It is effectively a snapshot of the root filesystem.  Commodity hardware servers have a bios that points the the master boot record of the first block on a disk.  A disk image though can sit anywhere physically on a disk, so Linux can boot from an...

How to vertically scale an Amazon instance?

Yes.  This is an incredible feature of AWS and cloud virtualization.  Spinup a new larger instance than the one you are currently running.  Pause that instance and detach the root ebs volume from this server and discard.  Then stop your live instance, detach its root volume.  Note...

What is auto-scaling? How does it work?

Autoscaling is a feature of AWS which allows you to configure and automatically provision and spinup new instances without the need for your intervention.  You do this by setting thresholds and metrics to monitor.  When those thresholds are crossed a new instance of your choosing will be...

What automation tools can I use to spinup servers?

The most obvious way is to roll-your-own scripts, and use the AWS API tools.  Such scripts could be written in bash, perl or other language or your choice.  Next option is to use a configuration management and provisioning tool like puppet or better it’s successor Opscode Chef.  You...

TOP AWS Interview Questions

A must 300+ AWS Questions (objective) 1. Mention what is the relation between an instance and AMI? 2. Explain EC2 Generation Instances in AWS? 3. What are the security best practices for Amazon EC2? 4. Explain how the buffer is used in Amazon web services? 5. Explain Elastic Block Storage?  What type of performance can you expect?  How do you back it up?  How...

What is configuration management? Why would I want to use it with cloud provisioning of resources?

Configuration management has been around for a long time in web operations and systems administration.  Yet the cultural popularity of it has been limited.  Most systems administrators configure machines as software was developed before version control – that is manually making changes on...

Explain how you would simulate perimeter security using Amazon Web Services model?

Traditional perimeter security that we’re already familiar with using firewalls and so forth is not supported in the Amazon EC2 world.  AWS supports security groups.  One can create a security group for a jump box with ssh access – only port 22 open.  From there a webserver group and...

How to use FullCalendar in MVC5

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How to pass JS variable value from View to Controller

One of the easiest approach to handle this problem is 1. Add a new property into your Model. 2. Create a hidden input control in view , which maps to the newly created property of your Model. 3. Update the value of your hidden control in js function. Let do it... 1.  Model         public class Model: GenericEntityPoco     {          ...