0.20.2 HDFS incompatible with 0.20.1

2010-01-05 Thread Todd Lipcon
Hey all, In a recent discussion, we noticed that the 0.20.2 HDFS client will not be wire-compatible with 0.20.0 or 0.20.1 due to the inclusion of HDFS-793 (required for HDFS-101). This begs a few questions: 1) Although we certainly do not guarantee wire compatibility between minor versions (0.20

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-05 Thread Allen Wittenauer
On 1/5/10 11:29 AM, "Todd Lipcon" wrote: > 1) Although we certainly do not guarantee wire compatibility between minor > versions (0.20 -> 0.21) have we previously implied wire compatibility > between bugfix releases? IIRC, it has been implied and was a goal but not officially written anywhere pub

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-05 Thread Owen O'Malley
On Jan 5, 2010, at 11:29 AM, Todd Lipcon wrote: 1) Although we certainly do not guarantee wire compatibility between minor versions (0.20 -> 0.21) have we previously implied wire compatibility between bugfix releases? Correction. Pre-1.0, the 0.N to 0.N+1 is a major upgrade. After 1.0, 1.

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-05 Thread Sanjay Radia
On Jan 5, 2010, at 2:06 PM, Owen O'Malley wrote: On Jan 5, 2010, at 11:29 AM, Todd Lipcon wrote: > 1) Although we certainly do not guarantee wire compatibility between > minor > versions (0.20 -> 0.21) have we previously implied wire compatibility > between bugfix releases? Correction. Pr

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Doug Cutting
Owen O'Malley wrote: Correction. Pre-1.0, the 0.N to 0.N+1 is a major upgrade. After 1.0, 1.N to 1.N+1 is a minor. In both cases, X.Y.z to X.Y.z+1 is a patch release. I thought we had it documented somewhere, but can't find it. http://wiki.apache.org/hadoop/Roadmap Doug

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Jean-Daniel Cryans
>From the HBase point of view, we would want to include hadoop 0.20.2-dev in hbase 0.20.3 specifically for HDFS-101 (127 would also be nice since we could stop patching the jar we distribute). We also share the same rules as hadoop and we don't want to break compatibility between point releases (we

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Owen O'Malley
Hairong was having difficulty getting this message through the spam filters. -- Owen Start of the message: > I would like Hairong to consider if she could fix the issue in 0.20 > without the incompatible change. It is possible that I fix the issue in 0.20 without breaking th

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Dhruba Borthakur
> I would like to propose that we pull out HDFS-793 and HDFS-101 from 0.20. +1 to pulling it out. This code is very tricky and is dangerous to change in a minor release. thanks, dhruba

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Owen O'Malley
On Jan 6, 2010, at 10:31 AM, Dhruba Borthakur wrote: I would like to propose that we pull out HDFS-793 and HDFS-101 from 0.20. +1 to pulling it out. This code is very tricky and is dangerous to change in a minor release. +1 to pulling it out. -- Owen

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Todd Lipcon
On Wed, Jan 6, 2010 at 10:31 AM, Dhruba Borthakur wrote: > > I would like to propose that we pull out HDFS-793 and HDFS-101 from 0.20. > > +1 to pulling it out. This code is very tricky and is dangerous to change > in > a minor release. > > -0 to pulling it out - I agree that it's very tricky, bu

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Allen Wittenauer
On 1/6/10 10:54 AM, "Todd Lipcon" wrote: > -0 to pulling it out - I agree that it's very tricky, but I think HDFS-101 > is a pretty big bug to knowingly leave in. In my experience this has been > the singular cause behind a lot of HDFS write problems when a cluster has a > couple of "bad egg" n

Re: 0.20.2 HDFS incompatible with 0.20.1

2010-01-06 Thread Sanjay Radia
Start of the message: > I would like Hairong to consider if she could fix the issue in 0.20 > without the incompatible change. It is possible that I fix the issue in 0.20 without breaking the compatibility. But I am worried about the code stability if we take this approach.