AWS - Snowball

Snowball is Amazon's data import/export solution in/out Amazon cloud, in case of large amount of data.

Amazon provides Snowball appliances you load/save data and send it to Amazon to load/save data in cloud. Once data transfer completes & verified Amazon performs software erasure of the appliance to clean the data from device.

Benefits: It comes with multiple layers of security with 80 and 50 TB capacity.

• Simple 
• Fast
• Secured 
• Encrypted with AES-256
• Cost saving (one-fifth of high speed internet)
• Tamper resistant 
• Industry standard Trusted Platform Module (TPM): End to end full chain of custody for your data

Types of Snowball

1. Snowball:  80 and 50 TB storage
2. Snowball Edge: Same kind of normal Snowball with 100 TB storage + Computation capability
• Computation capabilities
• Can run Lambda functions
• Its a kind of cloud on premise
• It can create one level of tier between local system and cloud. In case of poor connections/offline on remote locations (offices) system/application can still work   
3. Snowmobile: Its a 45 foot long ruggedized(shock proof) shipping container with 100 PB data transfer capacity.
   

It can be used to move massive volumes of data to Amazon. That can include video libraries, images database or even complete data center migration.

Key Points : 

1. Snow ball can import data from S3 and export data to S3. If your data stored in Glacier then you need to retrieve data from Glacier to S3 then S3 to Snowball.

Weak & Strong Reference

Weak Reference: If we references of some other dlls/assemblies in our program and those assemblies are not signed then the reference to those assembly called Weak Reference.
Why? : A same name assembly with same namespace and class names can be replaced with original one. Our program can't identify the Fake assembly.
If we sign the assembly then our program also check the signed key of the reference assembly.

Strong Reference: Reference a signed assembly in our program is Strong Reference.