Hot and cold data storage

HOT COLD

Unified Virtual File SystemFor Hot & Cold Data Storage

Aditya Ambre Madhura S. Raghavan Rohit Arora

ENTERPRISE STORAGE ARCHITECTURE

GROUP 2

HOT COLD

CSC 568 Enterprise Storage Architecture (NC State University)

AGENDA

➔ Problem Statement

➔ Project Goals and Features

➔ Architecture and Workflow

➔ Verification Cases

➔ Summary

Least Frequently Accessed

Data

HOT COLD


PROBLEM STATEMENT

➔ Lifecycle of Data.

◆ Access frequency.

◆ Storage capacity and hardware characteristics.

➔ User intervention - Running jobs/scripts.

➔ Acknowledging Data temperature

➔ Tight coupling needed between storage components

FrequentlyAccessed

Data

HOT COLD


WHAT IS A HOT FILE?

Data File that

➔ Very frequently accessed.

➔ Mostly contains business critical information.

➔ Needs to be accessed quickly.

HOT COLD


WHAT IS A COLD FILE?

Data File that

➔ Is infrequently accessed.

➔ Contains less important information.

➔ Need not be quickly accessed.

HOT COLD


GOAL: WHAT OUR PROJECT IS?

➔ From decoupled storage components - To - tightly coupled two-

tiered storage system

➔ Manage hot & cold data between primary and secondary storage.

➔ Manage primary storage space utilization.

➔ File transfer do not interrupt FS operations.

➔ User agnostic about file transfer and storage.

➔ Optimal storage of cold data.

HOT COLD


WHAT OUR PROJECT IS?

HOT COLD


FEATURES

➔ Infinite Storage illusion

➔ Automatic cold data identification and transfer

➔ Consistent CRUD operations for both hot and cold files

➔ Block level storage

➔ On the fly deduplication

➔ Uninterrupted file access

➔ File level Consistency

➔ Optimal storage space utilization

HOT COLD


OUR ARCHITECTURE

Cold File Tracking

Hot File Tracking

File TrackingLayer

Data Block Processing Layer

Write block to cold

Get block from cold

De-duplication

COLD STORAGE

APPLICATION

Write Read

FUSE OPERATIONSRead, Write, Delete, Rename, etc.

2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

Hot File

Cold File

HOT COLD


HOT-TO-COLD WORKFLOW

COLD STORAGE

APPLICATION

Write

FUSE {WRITE} OPERATIONS

File TrackingLayer


HOT COLD



COLD STORAGE

APPLICATION

Write

FUSE {WRITE} OPERATIONSCheck: Storage > 70%

File TrackingLayer


HOT COLD



COLD STORAGE

APPLICATION

Write


Cold File Tracking

File TrackingLayer


HOT COLD



File Tracking Layer

1. List all the files

2. Sort files by access time - oldest to newest

3. Select files to be transferred - (till <=50%)

4. Sort above files by size - large to small

5. Send the largest & least accessed files to

Data Processing layer

Cold File tracking

HOT COLD



File TrackingLayer

File 11:30 PM100 KB

File 24:30 PM500 KB

File 33:30 PM250 KB

File 42:30 PM350 KB

File 11:30 PM100 KB

File 24:30 PM500 KB

File 33:30 PM250 KB

File 42:30 PM350 KB

File 11:30 PM100 KB

File 42:30 PM350 KB

File 33:30 PM250 KB

HOT COLD



COLD STORAGE

APPLICATION

Write


File TrackingLayer

Cold File Tracking


Write block to cold

Cold File

2f0f3ff2…7439635…e7faa85…3f35ec5f…e4ae0b9...

HOT COLD



Data BlockProcessing Layer

1. Request Hashtable2. Get Hashtable

Write Blockto Cold

COLD STORAGE

1. Request Hashtable

2. Gets Hashtable

HOT COLD




1. Request Hashtable2. Get Hashtable3. Calculate block level hash4. Check for de-duplication

Write Blockto Cold

COLD STORAGE

4. Duplicate? 2f0f3ff2…7439635…e7faa85…3f35ec5f…e4ae0b9...

Block 1

Block 2

Block 3

HOT COLD




1. Request Hashtable2. Get Hashtable3. Calculate block level hash4. Check for de-duplication5. Transfer if not duplicate6. Free block’s memory

Write Blockto Cold

COLD STORAGE

5. Transfer Block


5. UpdateHashtable

Block 1 Block 2 Block 3

HOT COLD




1. Request Hashtable2. Get Hashtable3. Calculate block level hash4. Check for de-duplication5. Transfer if not duplicate6. Free block’s memory7. Send updated hashtable to

cold storage

Write Blockto Cold

COLD STORAGE

7. Send Updated

Hashtable


6.

HOT COLD



COLD STORAGE

APPLICATION

Write

FUSE {WRITE} OPERATIONSCheck: Storage <= 50%

File TrackingLayer

Cold File Tracking


Write block to cold

Cold File De-duplication


HOT COLD


COLD-TO-HOT WORKFLOW

COLD STORAGE

APPLICATION

FUSE {READ} OPERATIONS

File TrackingLayer


ReadRequest


HOT COLD



COLD STORAGE

APPLICATION


File TrackingLayer


ReadRequest

Check: Is File on Hot Storage?2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

HOT COLD



COLD STORAGE

APPLICATION


File TrackingLayer


ReadRequest

Check: Is File on Hot Storage?

Get block from cold

No 2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

HOT COLD




1. Request copy of Hashtable2. Get Hashtable

Get Blockfrom Cold

COLD STORAGE

1. Request Hashtable

2. Gets Hashtable


HOT COLD




1. Request copy of Hashtable2. Get Hashtable3. Read block presence on cold

Get Blockfrom Cold

COLD STORAGE

3. Is block present?

HOT COLD




1. Request copy of Hashtable2. Get Hashtable3. Read block presence on cold4. Request/Get block from cold

Get Blockfrom Cold

COLD STORAGE

4 Request Block

4. Gets Block



Block 1 Block 2 Block 3


HOT COLD




1. Request copy of Hashtable2. Get Hashtable3. Read block presence on cold4. Request/Get block from cold5. Write transferred’ block

content to memory block6. Construct complete file

Get Blockfrom Cold

COLD STORAGE

Block 1

Block 2

Block 3

6.


HOT COLD




1. Request copy of Hashtable2. Get Hashtable3. Read block presence on cold4. Request/Get block from cold5. Write transferred’ block

content to memory block6. Construct complete file7. Delete copy of Hashtable

Get Blockfrom Cold

COLD STORAGE

Block 1

Block 2

Block 3

7. DeleteHashtable

HOT COLD



COLD STORAGE

APPLICATION


File TrackingLayer


ReadReadRequest

Get block from cold

Block Read

Request

No 2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

HOT COLD


MINIMAL THRESHOLD WORKFLOW

COLD STORAGE

APPLICATION


File TrackingLayer


Some Operation

Get block from cold

Block Read

Request

Yes 2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

Check: Storage <= 30%

Get Cold FileHot File Tracking

HOT COLD


READ OPERATION WORKFLOW

COLD STORAGE

APPLICATION


File TrackingLayer


Some Operation

Get block from cold

Block Read

Request

Yes 2f0f3ff2c7439635e7faa85…3f35ec5fe4ae0b963779c8…4a8f9ec938243beac4b2d…

Check: Storage >30% & < 70%

Get Cold FileHot File Tracking

HOT COLD


QUICK DEMO

http://www.youtube.com/watch?v=KmHnOw8BS-c

HOT COLD


SCENARIOS / VERIFICATION CASES

I. GENERAL

➔ File System 70% full -> Transfer to cold storage.

➔ File System drops less than 30% -> Transfer from cold storage.

➔ File transfers -> Do not interrupt general FS operations.

➔ Redundant/Duplicate blocks ->Not transferred.

HOT COLD


SCENARIOS / VERIFICATION CASES

II. SPECIFIC

➔ Files transferred –> Based on access and size.

➔ File removed on hot storage –> After last block is transferred.

➔ File in transition accessed –> Abort transfer, access granted!

➔ File space reclamation and File access –> Synchronized.

➔ Only one background process running at specific time.

➔ Delayed delete (rm) -> Transparent to user.

HOT COLD


ASSUMPTIONS

➔ Network is always available.

➔ Hot-Cold classification at file level

➔ Cold Storage is infinite.

➔ Files are not very small or very large.

➔ Delay is accepted for rarely accessed files.

➔ File access granularity – in seconds.

HOT COLD


SUMMARY

➔ Acknowledged data temperatures - hot and cold

➔ Project Features

◆ Auto file identification.

◆ File transfer

◆ Deduplication

➔ Architecture and workflows in action.

➔ Design and implementation of file tracking layer

➔ Design and implementation of Block Data Process Layer

➔ Design decisions for specific verification scenarios.

HOT COLD


FUTURE SCOPE

➔ Variable block size and Block size specifications.

➔ Garbage collection on secondary/cold storage.

➔ Cold file identification parameters and profiles.

➔ Distributed cold storage.

HOT COLD


REFERENCES

1. S. Quinlan and S. Dorward, “Venti: A new approach to archival storage,” in Proceedings of the First USENIX Conference on File and Storage Technologies (FAST), 2002. http://plan9.bell-labs.com/sys/doc/venti/venti.pdf

2. Chuanyi Liu, Dapeng Ju, et al, “Semantic data de-duplication for archival storage systems,” in Proceedings of the 13th IEEE Asia-Pacific Computer Systems Architecture Conference (ACSAC 2008), Hsinchu, Taiwan, August, 2008.

3. Sean Quinlan, Jim McKie Russ Cox, “Fossil, an Archival File Server”, Lucent Technologies Bell Labs, Unpublished memorandum (September 2003).

4. http://www.storiant.com/resources/Cold-Storage-Is-Hot-Again.pdf

5. “What is Unified Storage system ” http://searchstorage.techtarget.com/definition/unified-storage

6. File System in User Space - http://fuse.sourceforge.net/

http://plan9.bell-labs.com/sys/doc/venti/venti.pdf



http://www.storiant.com/resources/Cold-Storage-Is-Hot-Again.pdf

http://www.storiant.com/resources/Cold-Storage-Is-Hot-Again.pdf

http://searchstorage.techtarget.com/definition/unified-storage



HOT COLD


QUESTIONS ?

Engineering

Hot and cold data storage