On 11/2/2018 3:12 AM, Vadim Ivanov wrote:
It seems to me that issue related with: - restart solr node - rebalance leader - reload collection - reload core (Core admin is not forbidden but seems obsolete in SolrCloud)
In SolrCloud, CoreAdmin is an expert option. Many of the things that the Collections API does are implemented internally with code that includes calls to the CoreAdmin API ... but using CoreAdmin directly is strongly discouraged, especially for anything related to manipulating replicas or creating indexes. It is possible to use CoreAdmin for many of these things successfully, but it's also very easy to use it incorrectly and cause problems that are difficult to fix. We recommend not using it at all, even if you're intimately familiar the SolrCloud code.
When you reload a collection, all cores (shard replicas) that make up the collection are reloaded, even if they are on separate machines. So you do not need to use CoreAdmin to do a reload. Situations where one core in a collection needs a reload but other cores do not are rare.
None of what I've written above addresses the problem that started the thread, it's about your note in parentheses on this message.
I don't know any more than the other people responding do about why your replica is getting out of sync. If you can come up with simple step by step instructions for reproducing the problem that begin with "download the X.Y.Z binary version of Solr", that will make it much easier to diagnose. Until the issue can be seen first-hand and there's something useful in Solr's log, we're guessing about what could be going wrong. Once we can reproduce it, the odds of getting you a new version that doesn't have the problem go up significantly.
Thanks, Shawn
