Hi Edwin, I'd like to rule something out. Does your schema define a field "_root_"? If you don't have nested documents then remove it. It's presence adds indexing weight in 8.0 that was not there previously. I'm not sure how much though; I've hoped small but who knows.
~ David Smiley Apache Lucene/Solr Search Developer http://www.linkedin.com/in/davidwsmiley On Tue, Apr 2, 2019 at 10:17 PM Zheng Lin Edwin Yeo <edwinye...@gmail.com> wrote: > Hi, > > I am setting up the latest Solr 8.0.0, and I am re-indexing the data from > scratch in Solr 8.0.0 > > However, I found that the indexing speed is slower in Solr 8.0.0, as > compared to the earlier version like Solr 7.7.1. I have not changed the > schema.xml and solrconfig.xml yet, just did a change of the > luceneMatchVersion in solrconfig.xml to 8.0.0 > uceneMatchVersion>8.0.0</luceneMatchVersion> > > On average, the speed is about 40% to 50% slower. For example, the indexing > speed was about 17 mins in Solr 7.7.1, but now it takes about 25 mins to > index the same set of data. > > What could be the reason that causes the indexing to be slower in Solr > 8.0.0? > > Regards, > Edwin >