Hi,

There seems to be continuous changes to the 'branch-0.20-security' and also
there are references to it once in a while in the mailing list. What is the
significance of the 'branch-0.20-security'? Do all the security related
features go into this branch and then ported to others?

Thanks,
Praveen

It is kind of a long history and I will try to leave out all of the politics involved to make it shorter.  For a long time 0.20 has been the stable release of Hadoop.  It is supposedly in sustaining releases now, but many new features keep going in because that is what most people use in production and they do not want to wait several years for a new interesting feature.  One of the very big features that went in is security.  There was a separate branch created for it which is branch-0.20-security.  Branch-0.20-security has essentially replaced branch-0.20 as the 0.20 release branch.  All features that go into branch-0.20-security or any other release branch are also supposed to go into trunk first, if they are not specific to branch-0.20-security.  So in theory everything in any release has also been applied to trunk.

--Bobby Evans

On 9/28/11 9:01 AM, "Praveen Sripati" <[EMAIL PROTECTED]> wrote:

Hi,

There seems to be continuous changes to the 'branch-0.20-security' and also
there are references to it once in a while in the mailing list. What is the
significance of the 'branch-0.20-security'? Do all the security related
features go into this branch and then ported to others?

Thanks,
Praveen

On 28/09/11 15:25, Robert Evans wrote:
> It is kind of a long history and I will try to leave out all of the politics involved to make it shorter.  For a long time 0.20 has been the stable release of Hadoop.  It is supposedly in sustaining releases now, but many new features keep going in because that is what most people use in production and they do not want to wait several years for a new interesting feature.  One of the very big features that went in is security.  There was a separate branch created for it which is branch-0.20-security.  Branch-0.20-security has essentially replaced branch-0.20 as the 0.20 release branch.  All features that go into branch-0.20-security or any other release branch are also supposed to go into trunk first, if they are not specific to branch-0.20-security.  So in theory everything in any release has also been applied to trunk.
>

That said. the new MR engine in 0.23 means that changes to the mapreduce
classes can't be backported from trunk to 0.20.x. Changes there should
go into 0.22 and then into 0.20-security

Steve,

> That said. the new MR engine in 0.23 means that changes to the mapreduce
classes can't be backported from trunk to 0.20.x. Changes there should go
into 0.22 and then into 0.20-security.

As far as I know, 0.22/0.20-security are on the old MR engine and 0.23/trunk
are on the new MR Engine. So, why backport 0.23/trunk -> 0.22 ->
0.20-security and not backport 0.23/trunk -> 0.20-security directly? Hope
it's not a dumb question :)

Thanks,
Praveen

On Wed, Sep 28, 2011 at 9:06 PM, Steve Loughran <[EMAIL PROTECTED]> wrote:

> On 28/09/11 15:25, Robert Evans wrote:
>
>> It is kind of a long history and I will try to leave out all of the
>> politics involved to make it shorter.  For a long time 0.20 has been the
>> stable release of Hadoop.  It is supposedly in sustaining releases now, but
>> many new features keep going in because that is what most people use in
>> production and they do not want to wait several years for a new interesting
>> feature.  One of the very big features that went in is security.  There was
>> a separate branch created for it which is branch-0.20-security.
>>  Branch-0.20-security has essentially replaced branch-0.20 as the 0.20
>> release branch.  All features that go into branch-0.20-security or any other
>> release branch are also supposed to go into trunk first, if they are not
>> specific to branch-0.20-security.  So in theory everything in any release
>> has also been applied to trunk.
>>
>>
> That said. the new MR engine in 0.23 means that changes to the mapreduce
> classes can't be backported from trunk to 0.20.x. Changes there should go
> into 0.22 and then into 0.20-security
>