Clip ID

[doctortt]

Hi,

Can an expert tell me what a clip ID is? Is it just an ID assigned to an archived item?  How do you find out the clip ID of an archived item?

Thanks

[Michael_Bilsbor]

Hi,

The clip id is something we get back from Centera when storing an item.  It is something that the EMC API returns back to us when we pass it data and then we use that id in future to retrieve the item back.

Where it gets stored depends upon whether you are using the centera collections feature or not and whether the item is large or not.

So it can be in the collections table or it can end up in the savesetstore table.

[Liam_Finn1]

A little more info on Clip ID and Centera Storage

C Clip = Package containing user's data and associated metadata

Clip ID = Content Address that the system returns to the client. Points to the CDF file which, in turn, contains the CA to retrieve the C-Clip file.

CDF = C-Clip Descriptor File. XML file that the API creates when it separates metadata from actual data. This file includes the Content Addresses for all referenceds BLOBs and their associated metadata (C-Clips)

CA or Content Address = 128-bit. Identifier that uniquely addresses the content of a file and not its location. Unlike location-based addresses, Content Addresses are inherently stable and, once calculated, they never change and always refer to the same content. Calculated from object's binary representation

The process for storing in centera is as follows (this is just an outline)

Stored to Centera

1) Client presents data to Centera API to be archived
2) Unique content Address is calculated
3) Object is sent to Centera via Centera API over IP
4) Centera validates the CA and stores the object. Ensures content of object has not changed. If data has been modified, new CA will be generated, and object will be stored separately as its own blob.

5) Acknowledgement returned to application. Returned to API once a mirrored copy of C-Clip Descriptor File (CDF) and protected copy of BLOB have been safely stored in Centera repository. Once data object is stored in Centera repository, API is given a C-Clip ID.

Retrieved from Centera

1) Object is required by EV
2) EV queries local SQL table of C-Clip IDs and locates C-Clip ID for needed objects

3) Using Centera API, request is sent along with C-Clip ID to the Centera
4) Centera delivers requested info to application which, in turn, delivers to the client.

If you want more detailed info let me know. We can go so deep into how the CAS devices work it gets spooky