Solr Cloud and Range Facets

[Jamie Johnson]

I have a solr cloud setup wtih 2 servers, when executing a query against
them of the form:

http://localhost:8983/solr/select/?distrib=true&q=*:*&facet=true&facet.mincount=1&facet.range=dateTime&f.dateTime.facet.range.gap=%2B1MONTH&f.dateTime.facet.range.start=2011-06-01T00%3A00%3A00Z-1YEAR&f.dateTime.facet.range.end=2011-07-01T00%3A00%3A00Z&f.dateTime.facet.mincount=1&start=0&rows=0

I am seeing that sometimes the date facet has a count, and other times it
does not.  Specifically I am seeing sometimes:

<lst name="facet_ranges">
  <lst name="dateTime">
    <lst name="counts"/>
    <str name="gap">+1MONTH</str>
    <date name="start">2010-06-01T00:00:00Z</date>
    <date name="end">2011-07-01T00:00:00Z</date>
  </lst>
</lst>

and others
<lst name="facet_ranges">
  <lst name="dateTime">
    <lst name="counts">
      <int name="2011-06-01T00:00:00Z">250</int>
    </lst>
    <str name="gap">+1MONTH</str>
    <date name="start">2010-06-01T00:00:00Z</date>
    <date name="end">2011-07-01T00:00:00Z</date>
  </lst>
</lst>

What could be causing this inconsistency?