I am trying to upgrade our production solr instance from 4.7 to 5.3.1. Unfortunately when I do load testing I find the MatchAllDocsQuery is much slower in solr 5.3.1 compare to 4.7. (solr 5.3.1 is faster in load test with queries other than MatchAllDocsQuery). I asked solr-user and discussed with Yonik Seeley. He confirmed that he can see the problem too comparing solr 5.3.1 and 4.10.
here is the query I use:
for me the query is consistently about 60-70% slower on solr5 than solr4.
Yonik mentioned in his email "For me, 5.3.1
is about 5x slower than 4.10 for this particular query."