Blob Storage

Using Cerulean you can list blobs in a blob container. Both hierarchical (virtual folders/blobs) and flat listing is supported.

When listing blobs by default the blobs in a blob container are presented in hierarchical format i.e. they are presented in form of virtual folders and blobs. However you can easily toggle the view to flat listing and blobs are presented with their full name.

Pagination to view blobs is supported by default and you can easily navigate from one page of results to another page using Cerulean.

Apart from uploading files and folders from your local computer to your blob container, Cerulean includes some convenience utilities to create blobs.

Using Cerulean you can create an empty append blob or choose a local file and save it as an append blob. Similarly you can create an empty page blob or a page blob from a local file.

Cerulean prevents you from creating blobs of a certain type if that blob type is not supported by the storage account. For example, Cerulean will prevent you from creating an append blob in a "BlobStorage" kind of storage account.

Using Cerulean you can easily create a virtual folder inside a blob container.

Considering virtual folders cannot persist without blobs in them, Cerulean gives you an option of persisting that virtual folder by automatically creating a zero byte blob so that you can upload blobs in that virtual folder later on.

Consider a scenario where you have too many blobs in your blob container and you would like to find out certain blobs. Cerulean includes a convenient utility using which you can search for blobs in a blob container.

You can search for blobs using either a "prefix" (i.e. find all blobs, names of which begin with certain characters) or "contains" search (i.e. find all blobs, names of which contain certain characters).

Using Cerulean you can easily delete one or more blobs and virtual folders. While deleting, you can instruct Cerulean to delete a blob only if does not have any snapshots or delete base blob and its snapshots. Blob deletion happens via a background task.

In case of blobs, Cerulean enumerates over blobs and delete them one by one. In case of virtual folders, Cerulean lists the blobs in that virtual folder and then deletes those blobs one by one.

Deleting blobs in Cerulean is extremely fast. This is because Cerulean uses blob batch operation to delete the blobs which can delete up to 250 blobs in a single request (instead of 1 blob in a single request).

Using Cerulean you can manage properties of a blob. You can view system defined properties like created date, last modified date, etag, size etc. of a blob.

You can also manage properties like "cache control", "content encoding", "content language", "content type", "content md5", "access tier" etc. of a blob. Using Cerulean you can easily update these properties of a blob.

Another useful feature in Cerulean is that you can change these properties of more than one blob in bulk without changing the properties of each blob individually. For example, if you want to change "cache control" property of many blobs together, you can easily do so with Cerulean by simply selecting the blobs (and virtual folders) and then specifying the new property value. Cerulean takes care of the rest for you.

Using Cerulean you can manage (view and/or update) metadata (user-defined key/value pair) of a blob.

Using Cerulean you can manage snapshots of a blob. A snapshot is read-only copy of the blob.

Using Cerulean you list all snapshots of a blob, create a new snapshot, delete snapshot of a blob. You can also promote a snapshot. Promoting a snapshot will overwrite the base blob with the blob snapshot. You can download snapshot of a blob as well on your local computer. Lastly, you can set access tier of a blob version. Thus you can have a blob in one access tier (Hot, for example) while its snapshots can be in a different access tier (Archive, for example).

Using Cerulean you can create a Shared Access Signature (SAS) for a blob. You can create an ad-hoc SAS token/URL (i.e. without using any blob container access policy) or a SAS token/URL with a blob container shared access policy.

Using Cerulean you can manage lease on a blob. Lease protects a blob from accidental deletes and updates.

You can acquire a lease on the blob. You can acquire both a short term lease (valid for 15 - 60 seconds) or infinite lease on a blob. If you know the lease id of the lease on blob, then you can either renew the lease, change the lease (to get a new lease id) or release a lease all together. You can also break a lease. When breaking lease, Cerulean gives you an option to break the lease immediately or wait for some time (between 1 and 60 seconds) before breaking the lease.

Using Cerulean you can easily upload files and folders from your local computer to a blob container. You can select one or more files and upload them. You can also select one or more folders and upload them. You can also drag files and folders from your local computer and drop them on a blob container node in the UI to upload them. Upload functionality in Cerulean is quite flexible and feature rich. To learn more about upload functionality, see the upload section below.

Using Cerulean you can download one more blobs and virtual folders from a blob container to your local computer. Download blobs functionality in Cerulean is quite flexible and feature rich. To learn more about download functionality, see the download section below.

This is another unique feature of Cerulean where you can simply double click a blob to open and view it. Under the covers, Cerulean downloads the blob in temp folder and tries to open it with registered application for that blob type.

This is a neat feature in Cerulean where you can copy one or more blobs and virtual folders to application clipboard and then paste those items to another blob container or a file share in same or different storage account.

What paste does is that it initiates a background task and there it copies the blobs from source to target asynchronously. In case of virtual folders, Cerulean will continuously list the blobs in the source virtual folder (what was copied) and copies those blobs asynchronously in the target blob container or a file share. Target blob container or file share can be in the same or different storage account.

Considering copy blob operation is an asynchronous server-side operation, you can instruct Cerulean to wait for the server-side copy operation to complete before marking a blob as completely copied.

When pasting blobs in a storage account that supports access tiers, you can set the access tier of the copied blob. This enables you to copy blobs directly in archive, cool or hot access tier.

Using Cerulean you can rename a blob or a virtual folder. Please note that Azure Storage does not natively support rename operation. The way Cerulean accomplishes this is by copying the existing blob to a new blob with the new name and then deleting the original blob.

In case of virtual folder renaming, Cerulean will list the blobs in the virtual folder. Once the blobs are listed, it copies the existing blob to a new blob by replacing the existing virtual folder name with new virtual folder name. Once the copy is complete, Cerulean simply deletes the old blob.

Using Cerulean you can easily change access tier (hot, cool, and archive) of one or more blobs and or virtual folders.

When changing access tier of multiple items (blobs and/or virtual folders), a background task is initiated and that task takes care of performing the operations on selected blobs and virtual folders. For multiple items, access tier of blobs are changed using bulk/batch operation which allows you to change access tier of up to 250 blobs in a single operation thus making it extremely fast.

In case of blobs, Cerulean simply goes through the list of blobs and then changes their access tier. In case of virtual folder, Cerulean first lists the blobs in the virtual folder and then changes the access tier of blobs fetched.

When rehydrating blobs (i.e. changing the access tier of an archived blob to hot or cool), Cerulean enables you to provide a reydrate priority (standard or high). When you choose "high" rehydrate priority, blobs are rehydrated faster (usually in a few hours).

Changing blob access tier for multiple blobs in Cerulean is extremely fast. This is because Cerulean uses blob batch operation to perform this operation which can change acccess tier of up to 250 blobs in a single request (instead of 1 blob in a single request).

Using Cerulean you can easily view the soft deleted blobs that are there in a blob container. Soft deleted blobs are the ones that are marked for deletion but have not been deleted yet. Please see blob service section below to learn more about soft deletes.

Using Cerulean you can easily undelete a soft deleted blob.

You can customize the behavior of viewing soft deleted blobs. You can instruct Cerulean whether or not you wish to see soft deleted blobs when you're listing blobs in a blob container.

Using Cerulean you can easily manage versions of a blob. If you have enabled blob versioning on a storage account, Azure storage automatically creates versions of a blob. This is different than blob snapshots where you have to manually create a snapshot of a blob.

Using Cerulean you can view the list of versions of a blob. For each blob version, you can view it's properties, metadata and tags. You can create a shared access signature for a specific blob version. You can open or download a specific blob version. Cerulean also enables you to promote a blob version which overwrites the base blob with a blob version. Furthermore, you can also delete a specific blob version using Cerulean. Lastly, you can set access tier of a blob version. Thus you can have a blob in one access tier (Hot, for example) while its versions can be in a different access tier (Archive, for example).

Using Cerulean you can easily manage tags for a blob. If you have enabled blob tagging on a storage account, using Cerulean you can add, update or delete tags on a blob.

For blob deletes and change access tier operations, Cerulean performs these operation in a batch where you perform the operation (either delete or change access tier) on up to 250 blobs in a single request. This results in extremely fast execution of these operations (250 blobs are deleted in a single request instead of one blob getting deleted in a single request.)

Using Cerulean you can upload local files and folders from your local computer to a blob container. For uploading all blob types (block, append and page) are supported.

You can select one or more files from your local computer and upload them. You can also select one or more folders from your local computer and upload them. You can drag files and folders from your local computer and drop them either on blob container node or in blob viewer grid to upload them.

In Cerulean local files and folders are uploaded via a background task.

The benefit of uploading happening via a background task is that your UI is not impacted at all and you can continue to work in the UI without any sluggishness. Another major benefit of uploading via background task is that you can close the application and the background task can continue. You don't have to keep the application running while the upload process is running.

You can monitor the progress of the upload tasks by going into the task manager in the application. You can also cancel the upload task. Furthermore if a file fails to upload because of network issue, you can retry uploading that file from the task manager itself.

Cerulean uploads the files and folders in parallel. It smartly detects how many parallel operations should be running and uploads the files in parallel. In case of large file uploads where a file is split into chunks for uploading, even the chunks are uploaded in parallel. This enables much faster uploads.

When uploading a local file as page blob, upload happens sparsely. What that means is that only the pages that have non-zero bytes are uploaded. If Cerulean detects that a page has all zero bytes, then it skips uploading that page. This results in faster blob uploads.

Large files are uploaded by splitting the file in smaller chunks and uploading those chunks. Chunks are uploaded in parallel. This result in faster upload of large files.

Furthermore you're in control of the chunk size. This gives you great benefit when you're on a poor network connection as you can reduce the chunk size.

Assuming you're uploading HTML, CSS, JS, and image files for your website in blob storage and would want them to be stored in compressed format in blob storage using either GZIP or DEFLATE compression algorithm.

Cerulean can do this work for you. All you need to do is tell the extensions of the file names (e.g. .css, .js etc.) that you wish to compress before uploading and the compression algorithm (GZIP or DEFLATE) to use and Cerulean does the job of compressing the files and uploading them. While uploading compressed file, it automatically sets the content encoding property of the blob to either "gzip" or "deflate" based on the compression algorithm. Furthermore, if Cerulean detects that the compressed file size is more than the original file size, it picks up the original file instead of compressed one.

When uploading blobs in storage accounts that support archive/cool/hot access tiers, you can instruct Cerulean to upload blobs in a particular access tier. A good example of that would be to directly upload local backups in archive tier of blob storage. Previously you would have to upload the blobs first and then change the access tier separately.

You can instruct Cerulean to calculate MD5 hash of the file that is being uploaded and save that MD5 hash as "Content-MD5" HTTP property of the uploaded blob.

Uploading process in Cerulean is quite flexible. Other than the settings descibed above like deciding the chunk size, compression settings etc.), you can control the overwrite behavior i.e. what Cerulean should do in case it finds a blob by the same name as that of the local file. You can instruct Cerulean to either overwrite the blob or not overwrite it. Furthermore you can specify the file name extensions that should be uploaded as page blobs (e.g. .vhd, .vhdx etc.).

Using Cerulean you can download one or more blobs and/or virtual folders from a blob container to your local computer. You can also download an entire blob container as well to your local computer.

In Cerulean blobs are downloaded via a background task.

The benefit of downloading happening via a background task is that your UI is not impacted at all and you can continue to work in the UI without any sluggishness. Another major benefit of downloading via background task is that you can close the application and the background task can continue to run. You don't have to keep the application running while the download process is running.

You can monitor the progress of the download tasks by going into the task manager in the application. You can also cancel the download task. Furthermore if a blob fails to download because of network issue, you can retry downloading that blob from the task manager itself.

Cerulean downloads the blobs in parallel. It smartly detects how many parallel operations should be running and downloads the blobs in parallel. In case of a large blob download, a blob is split into chunks for downloading and then these chunks are downloaded in parallel. This enables much faster downloads.

When downloading page blobs, download happens sparsely. What that means is that Cerulean will only download those pages which have some data in it. Any page with no data (i.e. all bytes are zeroes) are not downloaded. This results in fast downloads.

When downloading large blobs, Cerulean automatically splits the blob in smaller chunks and then download those chunks. These chunks are downloaded in parallel. This results in faster downloads.

If a blob is compressed with GZIP or DEFLATE compression algorithm i.e. blob's content encoding is set as either "gzip" or "deflate", you can instruct Cerulean to automatically decompress it after download. You don't have to do anything special to decompress that file.

This is another neat feature in Cerulean where you can instruct Cerulean to set the date/time of the downloaded file to be that of the blob's last modified date/time instead of current date/time of the system.

Using Cerulean you can configure storage analytics settings for the blob service in your storage account.

You can configure (view/update) logging, minute metrics and hourly metrics settings for the blob service in your storage account.

Using Cerulean you can configure CORS settings for the blob service in your storage account.

Using Cerulean you can list the CORS rules defined for the blob service, add new CORS rule, update existing CORS rules or delete CORS rules.

Azure Storage has this neat feature wherein when you delete a blob, it is not actually deleted at that time. Rather it is soft deleted i.e. it is marked for deletion and unless you undelete that blob, it will automatically be deleted after certain time.

Using Cerulean you can configure the soft delete settings for blob service. You can enable/disable this setting and if this setting is enabled you can specify for how many days a blob should remain in "soft deleted" state before being deleted permanently.

You can host static websites (just HTML, JavaScript, CSS) in your blob storage in a storage account. However before you can do that, you will need to enable this feature.

Using Cerulean you can enable this feature. Once this feature is enabled, a special blob container by the name "$web" is created in your storage account and you can host your static website in that blob container.