Minimizing Changes to the BlackPearl API

Spectra Logic’s BlackPearl is a gateway to our deep storage that uses an Application Programming Interface (API) for archive and restore operations. This API is used by our partners to integrate their software with BlackPearl. With the success of BlackPearl, the list of partner software clients is growing quickly. With the larger list comes a very important question: what should Spectra do to keep changes in BlackPearl code from affecting partner integrations? Retesting every release of BlackPearl code with every client version is obviously not feasible. Instead, Spectra Logic has chosen to tightly control and minimize API changes to prevent problems with partner integrations. To achieve this, we have established an API change review process that involves all stakeholders within the Spectra organization, as well as external partners and customers.

The release process:

-- Requires that every type of proposed change to an existing API call has a sponsor and is logged in the engineering feature tracking system.

-- The proposed change has to be reviewed and approved by both Spectra’s Engineering and Product Management departments before it becomes scheduled for development.

-- Even when approved, any changes to API with potential to affect partners and customers have to be scheduled with sufficient lead time to allow proper communications to and changes by all stakeholders, including customers, partners, and Spectra Logic.

-- Finally, the process restricts API changes in BlackPearl to major releases (e.g. version 3.x to version 4.x). Changes in minor or “point” releases (e.g. 3.7 to 3.8) are not allowed unless the change is deemed critical by the directors of both our Engineering and Product Management department.

Please note that that new XML response elements and attributes are permitted, as they should be ignored by clients not taking advantage of a new response element. This behavior allows existing older clients to keep functioning with newer versions of API.

With all the controls built into the process, Spectra Logic aims to assure a stable and consistent API for interfacing with BlackPearl. At the same time, the process provides a means to expand the API to meet the needs of end users and support new applications and markets as they develop in the future.


Importing Foreign LTFS Tapes into BlackPearl

When BlackPearl writes data to tape, it uses the open Linear Tape File System (LTFS) file format. Because of this LTFS support, Spectra Logic was able to add the ability to import non-BlackPearl or “foreign” LTFS tapes to BlackPearl. This is useful for any customer that receives LTFS-formatted tapes from another source and wishes to read those same tapes in the BlackPearl environment. This workflow is particularly common in the Media and Entertainment industry as a way to transfer video files from one group to another. Since every application may utilize the open LTFS format in a different manner when writing data to tapes, it is important that the user verify the various LTFS tape formats will be properly imported for read only use in the BlackPearl environment.

BlackPearl will support the import of foreign LTFS tapes in version 3.5, which is due out in Q1 of 2017. Importing can be done manually via the BlackPearl web management interface or via an external application that calls the BlackPearl API. The “import” process we discuss herein assumes that the foreign LTFS tapes have already been physically imported into the tape library partition to which BlackPearl is connected. Additionally, when a foreign LTFS tape is added to a BlackPearl tape partition, the write-protect switch on the tape cartridge must be set to “read only” before BlackPearl will allow the tape to be imported.  BlackPearl will not ever modify the tape in any way. Also note that the API import commands must be initiated by the administrator or “spectra” user.

To manually import foreign LTFS tapes via the web management interface of BlackPearl, users will go to the Tape Management page (Status > Tape Management), click on the tape(s) to be imported, and then go to the Action menu and select Import Foreign Tape.

The tapes can also be imported via an external application that calls the BlackPearl API. While there are several possible workflows that can be taken to import the tapes into BlackPearl by an application, this is one we are currently recommending to our partners:

  1. Application calls API command Get Tapes to get a list of all tapes and their state. Tapes with a state of LTFS_WITH_FOREIGN_DATA should be recorded along with their barcodes.
  2. Application calls API command Raw Import All Tapes to start the process of importing the foreign LTFS tapes. Make sure to make this call using the admin user “spectra”. The application must provide a bucket name in which to import the files on the foreign LTFS tapes. Alternatively the application can call Raw Import Tape to import individual foreign LTFS tapes based on the barcodes recorded from Step 1 above. Again, each time this is called, a bucket name will need to be provided and using this method can allow the application to import different tapes into different buckets if desired.
  3. Application should periodically call API command Get Tapes again to check the state of all tapes. Once there are no more tapes with a state of LTFS Foreign, it means all foreign LTFS tapes have been successfully imported.
  4. Application calls API command Get Physical Placement for Object Parts on Tape to get a list of all files that are on each LTFS tape, using the barcodes recorded in Step 1 above as the input parameter for this call. The application can then read each of these files if needed, such as to create video proxies or to copy them to another location in BlackPearl. If the application doesn’t need to read the files, it can simply record the list of file names.
  5. If the application no longer needs the files on the foreign LTFS tapes, for example because it has read the files and copied them to another bucket in BlackPearl, it can then issue an Eject Tape command for each tape.

As you can see, it is quite easy for applications to work with foreign LTFS tapes in BlackPearl. It is important to remember that the user and/or developer need to confirm that the user’s LTFS tapes can be read by BlackPearl by testing them out. Also, note that BlackPearl will not generate a checksum for the files on foreign LTFS tapes as it does for other files that are imported into BlackPearl. We also don’t currently support importing foreign LTFS tapes that use “tape spanning”, or spanning one file across multiple tapes.

Foreign LTFS tape import is supported in released Java SDK 3.4.0-RC1, and it will be supported by any BlackPearl hardware with code 3.5 and higher. We will soon (in the next two months) also have the foreign LTFS tape import operations available in our other SDKs (C#/.NET, Python, C). We will also soon update our BlackPearl API documentation to include the new foreign LTFS tape import operations.

If you want help working with foreign LTFS tapes in your BlackPearl integration, please contact the Developer Program.


Developer Summit 2016 Recording and Slides

On November 10, 2016, we had a successful, second annual BlackPearl Developer Summit. We have provided a recording, slides, and agenda from the Summit below.

Summit Recording

Slides

Agenda

  • Corporate updates from Spectra CEO Nathan Thompson
  • BlackPearl product overview and enhancements
  • Learn what tools are available to help develop a BlackPearl client
  • Partner presentation detailing client development
  • Learn how easy it is to integrate an existing BlackPearl client into your workflow
  • Demonstration of Avid PAM and BlackPearl integration
  • Demonstration of CatDV BlackPearl integration
  • Question and answer with our BlackPearl Developer Program Team

 

 


Second Annual BlackPearl Developer Summit – Nov 10 2016

Thursday, November 10, 2016 — 9:00 a.m. MDT (UTC -7), WebEx

Join us for Spectra Logic’s second annual BlackPearl Developer Summit, a virtual conference for current and potential developers of Spectra® BlackPearl® Deep Storage Gateway.

Event Agenda:

  • Corporate updates from Spectra CEO Nathan Thompson
  • BlackPearl product overview and enhancements
  • Learn what tools are available to help develop a BlackPearl client
  • Partner presentation detailing client development
  • Learn how easy it is to integrate an existing BlackPearl client into your workflow
  • Demonstration of Avid PAM and BlackPearl integration
  • Question and answer with our BlackPearl Developer Program Team

November 10, 2016 — 9:00 a.m. MDT (UTC -7)
Check Time by Country

REGISTER NOW


Python SDK 3.0 Released

We have released new version 3.0.0 of our BlackPearl Software Development Kit (SDK) for the Python programming language. It is now available for download on GitHub. You can also view code documentation, code examples, and installation instructions on our Documentation page.

This new SDK is compatible with our current BlackPearl 3.0.1 release and allows access to all BlackPearl 3.0 API commands. Note that the previous version of the Python SDK (1.2.0) is also compatible with the current BlackPearl 3.0.1 release but does not give access to all API commands.

Significant code structure changes were made between the 1.2.0 and 3.0.0 release of the Python SDKs. If you will be upgrading an existing client from 1.2.0 to 3.0.0, you should read our Migration Guide, which describes the changes in more detail. We do not anticipate major code structure changes in the future.

The previous 1.x versions of the Python SDK required that that C SDK also be installed. This new 3.0.0 Python SDK is no longer dependent on the C SDK and therefore no longer requires that the C SDK be installed.

We call this 3.0.0 release a “Pre-Release” because, while it has been tested internally, it is not yet in use by any of our partners or customers.

With this SDK release, all four of our SDKs -- Python, C, Java, and .NET/C# -- are now up to date with BlackPearl 3.x code and support all BlackPearl API commands.

If you have any questions or run into any problems, please post your questions to our Forum.


BlackPearl 3.0 C SDK Now Available

We have released new version 3.0.0 of our BlackPearl Software Development Kit (SDK) for the C programming language. It is now available for download on GitHub. You can also view code documentation, code examples, and installation instructions on our Documentation page.

This new SDK is compatible with our current BlackPearl 3.0.1 release and allows access to all BlackPearl 3.0 API commands. Note that the previous version of the C SDK (1.2.0) is also compatible with the current BlackPearl 3.0.1 release but does not give access to all API commands.

Some code structure changes were made between the 1.2.0 and 3.0.0 release of the C SDKs. If you will be upgrading an existing client from 1.2.0 to 3.0.0, you should read our previous blog post Preparing for the BlackPearl 3.0 Release, which describes the changes in more detail.

We call this 3.0.0 release a “Pre-Release” because, while it has been tested internally, it is not yet in use by any of our partners or customers.

If you have any questions or run into any problems, please post your questions to our Forum.


Managing Ejected Tapes in BlackPearl

BlackPearl is an object storage gateway to Spectra’s archive disk and tape library products. Tape libraries have a unique feature not typically available in disk systems – the tapes can be ejected and removed from the tape library. This removal can allow for additional data protection by taking the tapes offsite, and it can also facilitate sharing of the data via physical transport. But once ejected and removed, the data on the tape can no longer be accessed by the tape library.

When a BlackPearl client requests data to be restored from BlackPearl, it is possible that the only copy of the data resides on tape(s) that have been ejected from the library. BlackPearl clients should be designed to handle this ejected tape scenario. Handling the ejected tape scenario is a requirement to pass Spectra certification.

BlackPearl Response to Data on Ejected Tape

When a client attempts to restore data from BlackPearl, it first issues a Create Bulk Get API command to BlackPearl. This command is used by the client to let BlackPearl know which files it wants to retrieve. If any of these files are only available on ejected tape(s), then BlackPearl’s raw API response will be as follows:

If the BlackPearl client is using one of our Software Development Kits (SDKs), which themselves call the Create Bulk Get API command, the SDK will throw an exception in this scenario. Here is the exception thrown by the Java SDK when requested files are only on ejected tapes:

Properly Handling Requests for Data on Ejected Tapes

You can see that in both responses above, BlackPearl indicates that one or more needed tapes are outside of the tape library and provides the barcode label(s) of the tape(s) that have been ejected in brackets. In the example above, the barcode label of the ejected tape is TEST079L7 . In most cases, simply displaying this message to the user should be adequate for the user to use the barcode label to go find the tapes and place them back in the tape library. The user can then try their restore request again and BlackPearl should be able to service it.

In some cases, the user may need more information about the tapes than just the barcode label. Tapes also have other ejection information associated with them, such as Eject Label and Eject Location, that users may need to find the tape. In that case, clients can register to receive a job failure notification. A job is what BlackPearl attempts to create when the Create Bulk Get command above is called. A notification is a message that BlackPearl sends to the client application. If the Create Bulk Get command can’t be serviced because a needed tape is outside of the library, then the job creation fails. BlackPearl clients can register to receive Job Creation Failed Notifications. These notifications includes detailed information about the ejected tapes that are needed to service the file restore request, including the Eject Label and Eject Location.

If a BlackPearl client wants to take a more proactive approach, the client can provide users with a means of checking to see if tapes are ejected before attempting a file restore. The Get Physical Placement API call, and its associated SDK calls, can be used to check the placement of a file or list of files. The Get Physical Placement response will include a list of specific locations where the files are located, whether that location is on disk, tape, or another BlackPearl. If the files are located on tape, the response will include the tape barcode labels and whether or not the tapes are ejected from the library. If the tapes are ejected, additional ejection information will be provided, including the Eject Label and Eject Location.

Message from BlackPearl Web Interface About Ejected Tapes

The BlackPearl web management interface includes a Messages page (Status > Messages) for viewing system event messages. Users can also set up their BlackPearl user account to receive these messages via email.

If a BlackPearl client attempts to restore files that are only available on ejected tapes, a warning message will be added to the Messages page. The message will indicate that a GET request was attempted but couldn’t be serviced because it requires tapes that are ejected from the library. The message will also include the barcode label, Eject Label, and Eject Location of all required ejected tapes. While these messages can be useful to the user, BlackPearl clients shouldn’t depend on the user having to access this Messages page to learn about the ejected tapes.

Conclusion

Developers should ensure that their BlackPearl client applications properly handle requests for data on ejected tapes. There are several methods available to address this scenario. Please Contact the Developer Team if you have any questions about managing ejected tapes.

 


New BlackPearl 3.0 C#/.NET SDK Now Available

We have released new version 3.0.0 of our BlackPearl Software Development Kit (SDK) for C#/.NET. It is now available for download on GitHub. You can also view code documentation, code examples, and installation instructions on our Documentation page.

This new SDK is compatible with our current BlackPearl 3.0.1 release and allows access to all BlackPearl 3.0 API commands. Note that the previous version of the C#/.NET SDK (1.2.5) is also compatible with the current BlackPearl 3.0.1 release but does not give access to all API commands.

We call this 3.0.0 release a “Release Candidate” (RC) because, while it has been tested internally, it is not yet in use by any of our partners or customers.

If you have any questions or run into any problems, please post your questions to our Forum.


Global Bucket Access Control Lists

We discussed BlackPearl bucket-level Access Control Lists (ACLs) in a past blog post. Bucket-level ACLs define the permissions on individual buckets. Global Bucket ACLs are also part of BlackPearl’s ACL framework and define what actions a user or group can take on all buckets stored on the BlackPearl. The Global Bucket ACL is independent of the bucket-level ACLs and bucket owner.

The following Global Bucket ACL permissions can be granted to users and groups:

  • List -- The user can see all buckets and can list the objects in all buckets.
  • Read -- The user can get objects and create GET jobs in all buckets.
  • Write -- The user can put objects and create PUT jobs in all buckets.
  • Delete -- The user can delete objects in all buckets, but cannot delete buckets.
  • Job -- The user can modify or cancel jobs in all buckets created by other users. The user can also see the details of jobs created by other users. Note that all users can view all jobs, but by default, only the initiator of the job can see the full details of a job.
  • Owner -- The user receives full access to all buckets, including all permissions listed above.

How to Use Global Bucket ACLs

Allowing certain users to access all the buckets on a BlackPearl system might be a key administration requirement at some BlackPearl sites.

In the below example the user has been granted global “List” rights. This means when this user logs in not only can they list every bucket on the system they can also list the contents of every bucket.

2016GlobalACLBlogPost-1

The Java Command Line Interface (CLI) is a simple BlackPearl client can be used to view these settings in action. The Java CLI get_service command will provide a list of all buckets on the BlackPearl to which a user has access. Because the user account being used by the Java CLI has global “List” rights, all buckets on the BlackPearl are displayed as shown below.

2016GlobalACLBlogPost-2

The “List” rights also allow the user to get a list of objects in a bucket, in this case the “Jom” bucket. The results are shown below.

2016GlobalACLBlogPost-3

The user does not have rights to retrieve/GET objects from any buckets. As shown in the image below, if the user attempts to get a file, they receive an error.

2016GlobalACLBlogPost-4

We could give the user the ability to retrieve/GET objects from BlackPearl by checking the “Read” permission box as shown in the image below.

2016GlobalACLBlogPost-5

When to Use Global Bucket ACLs

The main reason to use Global Bucket ACLs is for ease of administration. Use of Global Bucket ACLs could allow a user or set of users to administer all the buckets without having to log in with the primary administrator “Spectra” user account. One way to do that would be to set up a group of users and to apply the Global Bucket ACLs to that group. That way there is no need to edit individual user accounts to change access levels. You just simply add or remove users from the group. You can see an example below in the group settings dialog.

2016GlobalACLBlogPost-6

By using the Global Bucket ACLs, users are being granted access not only to existing buckets, but also buckets that will be created in the future. This may save the administrator the time of having to grant access to individual buckets as the buckets are created.


BlackPearl Certification Program

Spectra Logic has created the BlackPearl Certification Program to ensure that the BlackPearl clients created by our partners are robust and reliable. We have provided detailed information on how to get certified. All partners should strive to have their BlackPearl clients certified. We are now certifying our first clients and will be announcing them soon. If you are interested in having your client certified, please Contact Us.

BlackPearl Certification Program