Hi folks, We are today running under SOLR 6.6 on our production environnement. On the end of august, i planned to upgrade SOLR to 7.4 (7.5 since that moment) but I encounter some trouble. Our master SOLR is replicated to a slave SOLR. I tried to upgrade the replica first, this is this one that makes me trouble. This is a shared server half for a mysql replication server and the replication SOLR server. The server is running under debian 7 (wheezy) and java 1.8.0u45 The SOLR java HEAP is configured with a 12G Xmx value.
On this SOLR instance there is 6 cores. - 2 cores are dedicated to main search on 2 different website (they are each 20Gb) - 2 cores are dedicated for the autocpletion feature of these 2 websites (~2Gb each) - 2 other cores very small occasionnaly used by one of the website The SOLR instance in 7.5 is up and ready but no trafic is sent to it. On the 2 websites, one generated approximately between 5000 and 8000 requests / minute on SOLR on 2 handlers. One search handler is dedicated to complex search from the search bar and the other handler treat back search such a return document for a specified id or return the chained documents, this kind of stuff. The second website use identical handlers than the first one, the only difference is that it generates less SOLR requests : 1000 to 2000 requests / minute. To upgrade the master I need to send all the SOLR trafic on this instance. I first redirect the bigger one. The reponse time grown a lot but SOLR stabilized it quickly. After 10 minutes as all was ok, I redirect the the website with the lower trafic rate. And immediatly, the number of java processes quickly increased, on munin the device busy increased to 100% (read operations) and the load average of the server drastically grown, it reach 120, SOLR began to not respond. I tried this several time, sometimes it happens immmediatly sometimes after 10 minutes. I don't realy understand what's going on. For this upgrade, I also changed the basic fields type from tried fields to pointed fields but I don't think that make a difference. And the more incomprehensible is that all works fine in SOLR 6.6.I cna switch all the traffic without any issue. Does anybody have an idea of what can go wrong. Debian version ? java version ? configuration problem ? Thanks for you helpfull answers, Regards, Sébastien
