Optimize question

[Scott M.]

I recently installed Solr 7.1 and configured it to work with Dovecot for 
full-text searching. It works great but after about 2 days of indexing, I've 
pressed the 'Optimize' button. At that point it had collected about 17 million 
documents and it was taking up about 60-70GB of space. 

It completed once and the space dropped down to 30-45GB but since then it 
appears to be doing Optimize again on its own, regularly swelling up the total 
space used to double, then it shrinks again, stays a bit that way then it 
starts another optimize!

Logs show:
        4/22/2018, 11:04:22 PM
        WARN false
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
        4/23/2018, 3:18:35 AM
        WARN true
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
        4/23/2018, 7:33:46 AM
        WARN false
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
        4/23/2018, 9:48:32 AM
        WARN false
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
        4/23/2018, 11:25:13 AM
        WARN false
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
        4/23/2018, 1:00:42 PM
        WARN false
        DirectUpdateHandler2
        Starting optimize... Reading and rewriting the entire index! Use with 
care.
It's absolutely killing the computer this is running on. Now it just started 
another run...

In the logs all I see is entries like these, and it doesn't say anywhere 
optimize=true

2018-04-23 17:12:31.995 INFO  (qtp947679291-17200) [   x:dovecot] 
o.a.s.u.DirectUpdateHandler2 start 
commit{_version_=1598557836536709120,optimize=false,openSearcher=true,waitSearcher=false,expungeDeletes=false,softCommit=true,prepareCommit=false}