I have observed this behavior with several versions of solr (4.10, 6.1, and now 7.2)
I look in the admin console and look at a core and see that it is not "current" I also notice that there are lots of segments etc... I look at the latest timestamp on a record in the collection and see that it is over 24 hours old. I send a commit to the collection, and then see that the core is now current, and the segments are fewer. The commit worked This is the setting in solrconfig.xml <autoCommit> <maxTime>${solr.autoCommit.maxTime:60000}</maxTime> < openSearcher>false</openSearcher> </autoCommit> Our Solr startup sets solr.autoCommit -Dsolr.autoCommit.maxTime=60000 Yet it looks like we don't get commits regularity. This morning I saw several collections that hadn't had a hard commit in more than 24 hours. How can this be? I don't feel that we can rely on Solr's autocommit capability and this is disturbing -- This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you must not copy this message or attachment or disclose the contents to any other person. If you have received this transmission in error, please notify the sender immediately and delete the message and any attachment from your system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not accept liability for any omissions or errors in this message which may arise as a result of E-Mail-transmission or for damages resulting from any unauthorized changes of the content of this message and any attachment thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not guarantee that this message is free of viruses and does not accept liability for any damages caused by any virus transmitted therewith. Click http://www.emdgroup.com/disclaimer to access the German, French, Spanish and Portuguese versions of this disclaimer.