Just had an issue on our Solr cloud and wanted to point this out to the list at large.
The real-time "/get" handler is used by Solr Cloud's sync/recovery mechanism, so *DO NOT* remove it from SolrConfig if you are using Solr Cloud! We did (because we weren't using real-time get ourselves and we were trying to remove all the unnecessary stuff from solrconfig). What it means is that whenever a leadership change for a shard happens, ALL the replicas go into full recovery mode, since they can't determine whether they are in sync or not. There seem to get some "getVersions" messages which are implemented in the RealTimeGetComponent, and since these are required for cloud recovery, shouldn't there be more emphasis on this being a required component (or part of the Core Admin Handler so it can't be configured away?) We have the comments in schema that the _version field is mandatory for SolrCloud, I think we at least need something similar for the "/get" handler. I'll log a JIRA for this, but sending here first.