Thanks for the analysis, Gary. Whether we support 2 (actually more than 2) metrics frameworks in 0.96 can be debated in the next 2 months.
As Todd mentioned in the thread 'HBase 0.94.1', we will try our best to keep JMX interface the same across 0.94 and 0.96. Does this somehow reduce the concern you raised ? As for using MetricsContext, I assume the user also uses hadoop in his / her deployment. Then he / she should be aware of the deprecation of metrics.* classes in both hadoop 1.0 and 2.0 Meaning he / she should be prepared to endorse metrics2 framework. Correct me if I am wrong. On Tue, Jul 10, 2012 at 11:26 AM, Gary Helmling <[email protected]> wrote: > Do we have any usage of metrics2 currently in 0.94? If not, it seems > odd to deprecate existing metrics implementations. Aside from whether > or not we should deprecate in a point release, normally deprecation > happens when the new implementation you're supposed to move to has > already been added, so that you have both old and new versions in > parallel. > > If we deprecate existing metrics in 0.94 and only have metrics2 > implementation in 0.96, that gives no chance for switching back and > forth between the two in the same release. While most of the metrics > classes can be seen as private, I think that MetricsContext is > arguably a public interface. Implementing your own MetricsContext to > plugin to your own monitoring system is not that crazy a thing to do. > So if that is changing in the move from metrics to metrics2, I think > it would be hurting our users to not have both implementations > available at the same time. > > > On Tue, Jul 10, 2012 at 1:45 AM, Ted Yu <[email protected]> wrote: > > In another email thread 'HBase 0.94.1', Lars has kindly accepted the > motion > > that deprecating current metric classes be done for 0.94.1 > > > > Since 0.94.1 contains critical bug fixes, I want to get public opinion on > > closing this poll earlier than Friday. > > > > Thanks for the understanding. > > > > On Mon, Jul 9, 2012 at 9:05 PM, Otis Gospodnetic < > [email protected] > >> wrote: > > > >> +1 for deprecating and moving to metrics2 faster. > >> I'd normally make the same argument about deprecating that Lars H. made, > >> but I think current HBase metrics really need improvement, so if I had > >> voting power I'd vote to drop old stuff and move to metrics2 ASAP. > >> > >> Otis > >> > >> ----- Original Message ----- > >> > From: Ted Yu <[email protected]> > >> > To: [email protected] > >> > Cc: > >> > Sent: Saturday, July 7, 2012 10:23 AM > >> > Subject: deprecating (old) metrics in favor of metrics2 framework > >> > > >> > Hi, > >> > See the following comment for background: > >> > > >> > https://issues.apache.org/jira/browse/HBASE-4050?focusedCommentId=13408679&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13408679 > >> > > >> > metrics2 framework is in both hadoop 1.0 and hadoop 2.0 > >> > We would like to migrate to metrics2 framework. But maintaining two > >> metrics > >> > frameworks in HBase is costly and results in lower readability. > >> > > >> > However, if you have cluster monitoring tool that depends on (old) > >> metrics > >> > framework, we want to give you smooth migration experience. > >> > > >> > Please provide your opinions on whether (old) metrics framework > should be > >> > deprecated in 0.94 or in 0.96. > >> > > >> > Thanks > >> > > >> >
