1. Using BLOB Storage In this module- What is BLOB storage?
How do I access it?
What is Azure Drive?

2. What is a BLOB
Binary Large OBject

3. Need shared access
When running in a scaled environment, data must be in a shared location. The LB is not sticky.
Web
Role LB
Web
Role
Storage
Web
Role

4. BLOBs in Azure & Size Each BLOB can be up to 1TB in size.
You can have as many containers and BLOBs as you want.
Containers can be created/destroyed on the fly.

5. BLOB Addresses Pages/ Blob Blocks Account Container images videos
Account
Container
Blob
Pages/
Blocks
PIC01.JPG
images
Block/Page
PIC02.JPG
contoso
Block/Page
videos
VID1.AVI

6. Containers Similar to a top level folder Can hold up to 100TB of files
Can only contain BLOBs
Each container has an access level:
Private
Default, will require the account key to access
Full public read
Public read only
Full public read – anonymous access; ability to list contents of container; access to container data
Public read only – anonymous access; only list blob – not contents of container; no access to container data

7. Blob Containers Multiple Containers per Account Blob Container
Special $root container
Blob Container
A container holds a set of blobs
Set access policies at the container level
Associate Metadata with Container
List the blobs in a container
Including Blob Metadata and MD5
NO search/query. i.e. no WHERE MetadataValue = ?
Blobs Throughput
Effectively in Partition of 1
Target of 60MB/s per Blob
Slide Objective
Understand containers
Speaker Notes
Account can contain unlimited number of containers
Root container useful when serving Silverlight and flash out of Blob storage. May need to store Cross domain access policy files in root of the domain
Metadata is up to 8KB of name value pairs per container
Notes
A root container serves as a default container for your storage account. A storage account may have one root container. The root container must be explicitly created and must be named $root.
A blob stored in the root container may be addressed without referencing the root container name, so that a blob can be addressed at the top level of the storage account hierarchy. For example, you can now reference a blob that resides in the root container in the following manner:

8. Working with Containers

9. Working with BLOBs

10. Uploading a BLOB
Other Options
UploadFile
UploadText
UploadFromStream

11. Downloading a BLOB Other Options DownloadText DownloadByteArray
DownloadToFile

12. Container & BLOB Metadata
Simple Dictionary.
Must call SetMetadata() to persist to the store.

13. Snapshotting
Pins a version of your BLOB that is read only.

14. Two Types of Blobs Under the Hood
Block Blob
Targeted at streaming workloads
Each blob consists of a sequence of blocks
Each block is identified by a Block ID
Size limit 200GB per blob
Optimistic Concurrency via ETags
Page Blob
Targeted at random read/write workloads
Each blob consists of an array of pages
Each page is identified by its offset from the start of the blob
Size limit 1TB per blob
Optimistic or Pessimistic (locking) concurrency via Leases
Slide Objective
Understand different blob types
Speaker Notes
Block blobs are comprised of blocks, each of which is identified by a block ID.
You create or modify a block blob by uploading a set of blocks and committing them by their block IDs.
If you are uploading a block blob that is no more than 64 MB in size, you can also upload it in its entirety with a single Put Blob operation.
When you upload a block to Windows Azure using the Put Block operation, it is associated with the specified block blob, but it does not become part of the blob until you call the Put Block List operation and include the block's ID.
The block remains in an uncommitted state until it is specifically committed. Writing to a block blob is thus always a two-step process.
Each block can be a maximum of 4 MB in size. The maximum size for a block blob in version is 200 GB, or up to 50,000 blocks.
Page blobs are a collection of pages.
A page is a range of data that is identified by its offset from the start of the blob.
To create a page blob, you initialize the page blob by calling Put Blob and specifying its maximum size.
To add content to or update a page blob, you call the Put Page operation to modify a page or range of pages by specifying an offset and range. All pages must align 512-byte page boundaries.
Unlike writes to block blobs, writes to page blobs happen in-place and are immediately committed to the blob.
The maximum size for a page blob is 1 TB.
A page written to a page blob may be up to 1 TB in size but will typically be much smaller
Notes

15. Uploading a Block Blob THE BLOB Benefit
blobName = “TheBlob.wmv”;
PutBlock(blobName, blockId1, block1Bits);
PutBlock(blobName, blockId2, block2Bits);
…………
PutBlock(blobName, blockIdN, blockNBits);
PutBlockList(blobName, blockId1,…,blockIdN);
10 GB Movie
Block Id 1
Block Id 2
Block Id 3
Block Id N
Benefit
Efficient continuation and retry
Parallel and out of order upload of blocks
Windows Azure Storage
TheBlob.wmv
TheBlob.wmv

16. Page Blob – Random Read/Write
Create MyBlob
Specify Blob Size = 10 Gbytes
Sparse storage - Only charged for pages with data stored in them
Fixed Page Size = 512 bytes
Random Access Operations
PutPage[512, 2048)
PutPage[0, 1024)
ClearPage[512, 1536)
PutPage[2048,2560)
GetPageRange[0, 4096) returns valid data ranges:
[0,512) , [1536,2560)
GetBlob[1000, 2048) returns
All 0 for first 536 bytes
Next 512 bytes are data stored in [1536,2048)
512
1024
1536
2048
10 GB Address Space
2560
10 GB

17. Shared Access Signatures
Fine grain access rights to blobs and containers
Easiest way to allow an untrusted client to upload files to your blob account
Sign URL with storage key – permit elevated rights
Revocation
Use short time periods and re-issue
Use container level policy that can be deleted
Slide Objective
Introduce Shared Access Signatures
Speaker Notes
Shared Access Signatures provide access rights to containers and blobs at a more granular level than by simply setting a container’s permissions
Grant users access to a specific blob or to any blob within a specified container for a specified period of time.
Specify what operations a user may perform on a blob that's accessible via a Shared Access Signature.
Use HTTPS to protect the signature (it is like a short dated password)
Two approaches
Ad-hoc Use for very short dated single use scenarios
Policy based Use for longer dated revocable permission sets
Always endeavour to use Least Permission set possible
Notes

18. Sample Use Attach to container Create Read Policy for 10 Minutes
Create Write Policy for 10 Minutes
From Steve Marx’s blog:
The first statement creates the policy, which specifies read-only access for the next ten minutes. The second statement lists all the blobs in a container and creates a list of URIs that have the Shared Access Signature query string appended to them. I use this to data bind the View.aspx page. To grant write access to a specific blob, I could use the same code as above, except with Write permissions.
Attach to URI to apply

19. Content Delivery Network (CDN)
Scenario
Frequently accessed blobs
Accessed from around the world
Windows Azure Content Delivery Network (CDN) provides high-bandwidth global blob content delivery
20+ locations globally (US, Europe, Asia, Australia and South America), and growing
Same experience for users no matter how far they are from the geo-location where the storage account is hosted
Cost
US located CDN nodes 15c/GB + 1c/10,000 txn
Rest of World 20c/GB + 1c/10,000 txn
Traffic from Storage node to edge node at standard rates
Slide Objectives
Understand basic concept of a CDN
Understand at a high level how Windows Azure CDN works
Speaker Notes
The Windows Azure CDN provides edge nodes around the world
Data stored in CDN enabled storage accounts is retrieved from the origin storage container and cached at each edge node in a lazy load fashion
Windows Azure Customers have control over how long data is cached for.
Windows Azure CDN has 18 locations globally (United States, Europe, Asia, Australia and South America) and continues to expand
The benefit of using a CDN is better performance and user experience for users who are farther from the source of the content stored in the Windows Azure Blob service.
Windows Azure CDN provides worldwide high-bandwidth access to serve content for popular events.
Notes
delivery-network.aspx

20. Reach, Scale and Capability
OVER 3 TERABITS PER SECOND OF CAPACITY IS AVAILABLE FROM OUR 20+ GLOBAL LOCATIONS WITH 99.95% AVAILABILITY. CDN SERVICE SCALES AUTOMATICALLY WITHOUT USER INTERVENTION. LIVE INSIDE MICROSOFT FOR OVER 3 YEARS – NOW AVAILABLE TO AZURE CUSTOMERS.

21. How does it work?
Public
Blob
Container !
Edge Node 1

22. Windows Azure Drives Durable NTFS volume for Windows Azure Instances
Use existing NTFS APIs to access a network attached durable drive
Use System.IO from .NET
Benefits
Move existing apps using NTFS more easily to the cloud
Durability and survival of data on instance recycle
A Windows Azure Drive is a NTFS VHD Page Blob
Mounts Page Blob over the network as an NTFS drive
Local cache on instance for read operations
All flushed and unbuffered writes to drive are made durable to the Page Blob

23. Windows Azure Drive Capabilities
A Windows Azure Drive is a Page Blob formatted as a NTFS single volume Virtual Hard Drive (VHD)
Drives can be up to 1TB
A Page Blob can be mounted:
On one instance at a time for read/write
Using read-only snapshots to multiple instances at once
An instance can dynamically mount up to 16 drives
Remote Access via standard BlobUI
Can’t remotely mount drive.
Can upload the VHD to a Page Blob using the blob interface, and then mount it as a Drive
Can download the VHD to a local file and mount locally
Slide Objectives
Understand Drives at a high level
Speaker Notes
Backed by Page blobs
Allows Page blob to be accessed as a drive letter on a Compute instance
Read write is limited to a single instance as a time.
Data is cached for reads on local instance
All write flushed operations are immediately committed
Notes
delivery-network.aspx

24. How Windows Azure Drives WorksVM
Drive is a formatted page blob stored in blob service
Mount obtains a blob lease
Mount specifies amount of local storage for cache
NTFS flushed/unbuffered writes commit to blob store before returning to app
NTFS reads can be served from local cache or from blob store (cache miss)
Application
Drive X: OS
Local Cache
Lease
Slide Objectives
Understand Drives Mounting and Caching
Speaker Notes
A Windows Azure drive acts as a local drive mounted on the file system and is accessible to code running in a role.
The data written to a Windows Azure drive is stored in a page blob defined within the Windows Azure Blob service, and cached on the local file system.
Because data written to the drive is stored in a page blob, the data is Durable.
Notes
delivery-network.aspx
Windows Azure Blob Service
DemoBlob

25. Cloud Drive Client Library Sample
CloudStorageAccount account =
CloudStorageAccount.FromConfigurationSetting("CloudStorageAccount");
//Initialize the local cache for drives mounted by this role instance
CloudDrive.InitializeCache(localCacheDir, cacheSizeInMB);
//Create a cloud drive (PageBlob)
CloudDrive drive = account.CreateCloudDrive(pageBlobUri);
drive.Create(1000 /* sizeInMB */);
//Mount the network attached drive on the local file system
string pathOnLocalFS = drive.Mount(cacheSizeInMB, DriveMountOptions.None);
//Use NTFS APIs to Read/Write files to drive …
//Snapshot drive while mounted to create backups
Uri snapshotUri = drive.Snapshot();
//Unmount the drive
drive.Unmount();
Slide Objectives
Understand Drives API
Speaker Notes
In Storage Client API
No equivalent REST calls
A Windows Azure drive may be mounted as a writable drive, or as a read-only drive if it is created from a snapshot of a page blob.
To create a read-only drive, call the Snapshot method to create a new snapshot and return the snapshot's URI, then create a new instance of the CloudDrive object from the snapshot's URI and mount the drive
Before a role instance mounts a drive for the first time, it must initialize the cache by calling the InitializeCache method.
When a role instance mounts a writable drive, it acquires an exclusive-write lease on the associated page blob that it retains as long as the drive is mounted.
If the same role instance attempts to mount a drive with the same URI a second time, the operation is ignored and the Mount method returns the local path to the existing drive.
Notes

26. Failover with Drives Must issue NTFS Flush command to persist data
Use System.IO.Stream.Flush()
Read/Write Drives protected with leases
1 Minute lease expiry
Maintained by Windows Azure OS Driver
Unmount on RoleEntryPoint.OnStop
On failure
Lease will timeout after 1 minute
Re-mount drive on new instance
Slide Objectives
Understand Drives under Failure scenarios
Speaker Notes
All writes must be flushed to be persisted to the underlying Page Blob
Read/Write drives maintain a lease
Unmount drives in OnStop method of Role
In failure will need to wait for lease to expire < 1 minute before remounting
Notes
edf4c95d5e2a

27. Guidance Manage connection strings/keys in cscfg
Do not share keys, wrap with a service
Strategy for accounts and containers
You can assign a custom domain to your storage account

28. Windows Azure Guest Book Using Blobs
C:\WindowsAzurePlatformKit\Demos\WindowsAzureGuestBookUsingBlobs
demo

29. Q & A
ponderances?

30. Exploring Windows Azure Storage
C:\WAPTK\Labs\ExploringWindowsAzureStorageVS2010
Do Exercise 2
hands on lab time