Spectra Logic provides Software Development Kits (SDKs) for BlackPearl in several different programming languages to make it easier for our partners and customers to create integrations to BlackPearl. Some of the BlackPearl SDKs are used in Windows environments, particularly the Java and .NET SDKs. An issue was recently discovered in the way that these SDKs write large data blocks (64GB+) restored from BlackPearl on to disk.

In Windows, by default, when a file is created, Windows will initially reserve the space for the file on disk by filling the file with zeros. It then later replaces those zeros with the actual file byte content as it is received. When the files are 64GB or larger, it can take a very long time to write all of the zeros. In that time the file transfer from BlackPearl can time out, causing the SDK to have to resubmit its request to BlackPearl to restore the file. This resubmission causes the overall transfer process to take longer than it would if the resubmission did not occur. And in extreme cases with extremely large files (1TB+), the transfer can permanently fail.

To avoid this time out issue, the zeros should not be initially written in the file. This can be done by specifying that Windows Sparse Files be used. With Windows sparse files, per Microsoft, “the system does not allocate hard disk drive space to a file except in regions where it contains nonzero data”. Sparse files are therefore initially written much more quickly than non-sparse files.

We have updated our Java and .NET SDKs to use sparse files on restores. Partners and customers using these SDKs should update to the latest versions to ensure that they have this sparse file fix. However, the fixes in these SDKs will only be helpful if the “FileHelpers” class is being used, in which case the SDKs will be writing the restored files. For those organizations that are using these SDKs but have written their own code to write the restored files, they must implement sparse files themselves in their own code.

You can see examples of how Spectra Logic implemented sparse files in the SDKs:

• Sparse files example in Java SDK
• .NET SDK – Mark the newly created file as sparse; Implementation for the sparse call

Please Contact the Spectra Developer Program Team  if you need assistance with implementing sparse files with BlackPearl.

Our Engineering Team has released new versions of the .NET/C# and Java Software Development Kits (SDK), as well as the Java Command-Line Interface (CLI). There are a number of new features and bug fixes in these releases. Probably the most important new feature in these releases is improved support for the upcoming BlackPearl 3.0 release. We strongly recommend that developers currently building BlackPearl clients using the .NET or Java SDKs upgrade to these new SDKs so that their clients will be more compatible with BlackPearl 3.0. These new releases should not require any code changes.

BlackPearl 3.0 will be released soon, and shortly thereafter we will be releasing further updates to our SDKs to access the new version 3.0 features. Read about these upcoming additional SDK updates  in our recent blog post Preparing for the BlackPearl 3.0 Release.

Download Latest .NET SDK

Download Latest Java SDK

Download Latest Java CLI

We have posted a new set of video interview from partners and customers using BlackPearl. Hear why they chose to work with Spectra Logic and BlackPearl.

Partner and Customer BlackPearl Interviews (YouTube)

Spectra Logic will be at NAB 2015 in Las Vegas, Nevada, USA from April 11-16 in Booth SL 11816 displaying our products and meeting with customers and partners. The Developer Program team will be there in full force to help out developers and spread our message. We’ll be doing demos at our booth and showing how easy it is to get started with DS3 client development. We’ll also show some of the great client applications we have built using our own software development kits (SDKs) that allow users to easily move data to tape. Please stop by and visit us if you are in town.