A feature branch seems reasonable to me too. Note that the WASB connector will continue to exist, and live side-by-side with the new Azure Blob Filesystem (ABFS) connector. We will encourage users to move to the new ABFS connector, and all of our new feature and performance improvements will target the ABFS connector. ABFS will perform better at no additional cost, so I expect current users to migrate in time. The two connectors are compatible for mainline scenarios, but there are some uncommon features in WASB that we chose not to carry over in the initial implementation.
So we hope ABFS will replace the usage of WASB, but the WASB connector itself will continue to exist. Maybe we can remove WASB in the future some day, if nobody is using it.
I can confirm that nobody ever gets seek() right. :)
From: larry mccay <[hidden email]>
Sent: Tuesday, May 15, 2018 8:44 AM
To: Steve Loughran
Cc: Hadoop Common
Subject: Re: [DISCUSS] Branch Proposal: HADOOP 15407: ABFS
This seems like a reasonable and effective use of a feature branch and
branch committers to me.
On Tue, May 15, 2018 at 11:34 AM, Steve Loughran <[hidden email]>
> > Internal constraints prevented this feature from being developed in
> Apache, so we want to ensure that all the code is discussed, maintainable,
> and documented by the community before it merges.
> Has this code gone through ASF IP Clearance already?
> On Tue, May 15, 2018 at 10:34 AM, Steve Loughran <[hidden email]>
>> Chris Douglas I and I've have a proposal for a short-lived feature branch
>> for the Azure ABFS connector to go into the hadoop-azure package. This will
>> connect to the new azure storage service, which will ultimately replace the
>> one used by wasb. It's a big patch and, like all storage connectors, will
>> inevitably take time to stabilize (i.e: nobody ever get seek() right, even
>> when we think we have).
>> Thomas & Esfandiar will do the coding: they've already done the
>> paperwork. Chris, myself & anyone else interested can be involved in the
>> review and testing.
>> The initial HADOOP-15407 patch contains a new filesystem client for the
>> forthcoming Azure ABFS, which is intended to replace Azure WASB as the
>> Azure storage layer. The patch is large, as it contains the replacement
>> client, tests, and generated code.
>> We propose a feature branch, so the module can be broken into salient,
>> reviewable chunks. Internal constraints prevented this feature from being
>> developed in Apache, so we want to ensure that all the code is discussed,
>> maintainable, and documented by the community before it merges.
>> To effect this, we also propose adding two developers as branch
>> committers: Thomas Marquardt [hidden email]<mailto:tma
>> [hidden email]> Esfandiar Manii [hidden email]<mailto:e
>> [hidden email]>
>> Beyond normal feature branch activity and merge criteria for FS modules,
>> we want to add another merge criterion for ABFS. Some of the client APIs
>> are not GA. It seems reasonable to require that this client works with
>> public endpoints before it merges to trunk.
>> To test the Blob FS driver, Blob FS team (including Esfandiar Manii and
>> Thomas Marquardt) in Azure Storage will need the MSDN subscription ID(s)
>> for all reviewers who want to run the tests. The ABFS team will then
>> whitelist the subscription ID(s) for the Blob FS Preview. At that time,
>> future storage accounts created will have the Blob FS endpoint,
>> <accountName>.dfs.core.windows.net<http://dfs.core.windows.net>, which
>> the Blob FS driver relies on.
>> This is a temporary state during the (current) Private Preview and the
>> early phases of Public Preview. In a few months, the whitelisting will not
>> be required and anyone will be able to create a storage account with access
>> to the Blob FS endpoint.
>> Thomas and Esfandiar have been active in the Hadoop project working on
>> the WASB connector (see https://issues.apache.org/jira >> /browse/HADOOP-14552). They understand the processes and requirements of
>> the software. Working on the branch directly will let them bring this
>> significant feature into the hadoop-azure module without disrupting
>> existing users.
apologies, copying back in common-dev@ with my question about the code.
On Tue, May 15, 2018 at 2:36 PM, Sean Busbey <[hidden email]<mailto:[hidden email]>> wrote:
> Internal constraints prevented this feature from being developed in Apache, so we want to ensure that all the code is discussed, maintainable, and documented by the community before it merges.
Has this code gone through ASF IP Clearance already?
It's been submitted as a large .patch on the JIRA, which is an effective code donation, and Thomas and Esfandiar have done the paperwork to be able to commit straight to a branch. Part of that merge will include the usual verification that redistributed dependency artifacts aren't cat-X licensed.