protobuf version clarification

[Michael Howard <mh...@podiumdata.com>]

Installation doc should clarify which version of protobuf is required.

Tez installation doc at http://tez.apache.org/install.html says:

> This assumes that you have already installed ... Protocol Buffers (protoc
compiler) 2.5 or later

I initially installed protobuf 2.6.1 ... and mvn failed with:

> [ERROR] Failed to execute goal ... protoc version is 'libprotoc 2.6.1',
expected version is '2.5.0' -> [Help 1]

I observe that pom.xml says:
        <protobuf.version>2.5.0</protobuf.version>

At this point, it wasn't clear to me whether I should roll back to protobuf
2.5.0 or override the protobuf.version to be 2.6.1

For newbies like me, it would be helpful to have more clear instructions
regarding protobuf version on the installation page.


Thanks!
Michael

Re: protobuf version clarification

[Hitesh Shah <hi...@apache.org>]

Hi Michael,

Yes - that is indeed an error regarding the version of protobuf that needs to be used. Pretty much all of the Hadoop ecosystem components have standardized on protobuf-2.5.0. Newer versions would likely have worked assuming protobuf retained compatibility. 

In any case, you do need to switch back to protobuf-2.5.0. Modifying the pom would have likely fixed the build issue with Tez but you would have ended up facing errors when trying on a cluster as hadoop needs 2.5.0. 

Could you file a jira and submit a patch for this issue ( and if you came across any other confusing/unclear items in the documentation )?

thanks
— Hitesh


On Mar 22, 2015, at 8:34 AM, Michael Howard <mh...@podiumdata.com> wrote:

> Installation doc should clarify which version of protobuf is required. 
> 
> Tez installation doc at http://tez.apache.org/install.html says:
> 
> > This assumes that you have already installed ... Protocol Buffers (protoc compiler) 2.5 or later
> 
> I initially installed protobuf 2.6.1 ... and mvn failed with:
> 
> > [ERROR] Failed to execute goal ... protoc version is 'libprotoc 2.6.1', expected version is '2.5.0' -> [Help 1]
> 
> I observe that pom.xml says:
>         <protobuf.version>2.5.0</protobuf.version>
> 
> At this point, it wasn't clear to me whether I should roll back to protobuf 2.5.0 or override the protobuf.version to be 2.6.1
> 
> For newbies like me, it would be helpful to have more clear instructions regarding protobuf version on the installation page. 
> 
> 
> Thanks!
> Michael
>