Yes, this is actually confusing and the documentation ( https://lucene.apache.org/solr/guide/7_2/metrics-reporting.html) does not help either:
*Index Merge Metrics* : These metrics are collected in respective registries for each core (e.g., solr.core.collection1….), under the INDEX category. Basic metrics are always collected - collection of additional metrics can be turned on using boolean parameters in the /config/indexConfig/metrics. However, we do not see the merge-metrics being collected if the above config is absent. So what basic metrics are always collected for merge? And why do the merge metrics require an additional config while most of the others are reported directly? Thanks SG On Mon, Jan 8, 2018 at 2:02 PM, suresh pendap <sureshfors...@gmail.com> wrote: > Hi, > I am following the instructions from > https://lucene.apache.org/solr/guide/7_1/metrics-reporting.html > in order to expose the Index merge related metrics. > > The document says that we have to add the below snippet in order to expose > the merge metrics > > <config> > ... > <indexConfig> > <metrics> > <majorMergeDocs>524288</majorMergeDocs> > <bool name="mergeDetails">true</bool> > </metrics> > ... > </indexConfig> > ...</config> > > > > I would like to know why is this metrics not exposed by default just like > all the other metrics? > > Is there any performance overhead that we should be concerned about it? > > If there was no particular reason, then can we expose it by default? > > > > Regards > Suresh >
