On Wed, Feb 20, 2013 at 3:08 PM, Tsz Wo Sze <szets...@yahoo.com> wrote: > The reason to keep it around is that the HDFS-347 only support Unix but not > other OS.
Given that this is an optimization, and we have a ton of optimizations which don't yet run on Windows, I don't think that should be considered. Additionally, the Windows support has not yet been merged, nor is it in any release, so this isn't a regression. I would be happy to review an addition to the HDFS-347 branch which addresses this issue. But I don't think we should be maintaining two codepaths for the sake of an optimization on a platform which is not yet officially supported on trunk, especially when the old code path is _insecure_ and thus unusable in most environments. Todd > > ________________________________ > From: Todd Lipcon <t...@cloudera.com> > To: hdfs-dev@hadoop.apache.org; Tsz Wo Sze <szets...@yahoo.com> > Sent: Wednesday, February 20, 2013 3:06 PM > > Subject: Re: VOTE: HDFS-347 merge > > On Wed, Feb 20, 2013 at 3:01 PM, Tsz Wo Sze <szets...@yahoo.com> wrote: >> Also, the patch seems to have removed the existing short-circuit read >> feature (HDFS-2246). It is an incompatible change. I think the patch is >> farther away from being ready and I would keep my -1. > > The existing short circuit feature is insecure and was always > considered a stop-gap solution. If you read the history of that > feature, you can find comments like > https://issues.apache.org/jira/browse/HDFS-4476 where I pointed out > that it's only a stop-gap solution and the only reason I didn't veto > is that folks agreed to later replace it with the proper solution > (HDFS-347). > > Given that the API is the same, and this is an implementation detail, > it is not incompatible. There is no reason to keep the old > implementation around: it is both slower and unusable in the vast > majority of clusters, where the data directories are owned by an HDFS > user, and users of the cluster run under other unix credentials. > > -Todd > -- > Todd Lipcon > Software Engineer, Cloudera > > -- Todd Lipcon Software Engineer, Cloudera
