Solr 7.4.0 - bug in JMX cache stats?

[Bojan Šmid]

Hi,

  it seems the format of cache mbeans changed with 7.4.0.  And from what I
see similar change wasn't made for other mbeans, which may mean it was
accidental and may be a bug.

  In Solr 7.3.* format was (each attribute on its own, numeric type):

mbean:
solr:dom1=core,dom2=gettingstarted,dom3=shard1,dom4=replica_n1,category=CACHE,scope=searcher,name=filterCache

attributes:
      lookups java.lang.Long = 0
      hits java.lang.Long = 0
      cumulative_evictions java.lang.Long = 0
      size java.lang.Long = 0
      hitratio java.lang.Float = 0.0
      evictions java.lang.Long = 0
      cumulative_lookups java.lang.Long = 0
      cumulative_hitratio java.lang.Float = 0.0
      warmupTime java.lang.Long = 0
      inserts java.lang.Long = 0
      cumulative_inserts java.lang.Long = 0
      cumulative_hits java.lang.Long = 0


  With 7.4.0 there is a single attribute "Value" (java.lang.Object):

mbean:
solr:dom1=core,dom2=gettingstarted,dom3=shard1,dom4=replica_n1,category=CACHE,scope=searcher,name=filterCache

attributes:
      Value java.lang.Object = {lookups=0, evictions=0,
cumulative_inserts=0, cumulative_hits=0, hits=0, cumulative_evictions=0,
size=0, hitratio=0.0, cumulative_lookups=0, cumulative_hitratio=0.0,
warmupTime=0, inserts=0}


  So the question is - was this intentional change or a bug?

  Thanks,

    Bojan