Hi, Thank you all for your responses. I will try to answer your questions in one single message.
We are starting to investigate performance issues with a new customer. There are several bad practices (commit, sharding, replicas count and types, heap size, ...), that can explain these issues and we will work on it in the next few days. I agree we need to better understand specific usage and make some tests after fixing the bad practices. Anyway, one of the specific aspects is these huge servers, so I am trying to see what is the best way to use all these ressources. * Why do you want to split it up at all? Because one of the bad practices is a huge heap size (80 Gb). I am pretty sure this heap size is not required and anyway it doesn't respect the 31Gb limit. After determining the best heap size, if this size is near 31Gb, I imagine it is better to have several Solr JVMs with less heap size. For instance 2 Solr JVMs with 20 Gb each or 4 Solr JVMs with 10 Gb each. According to Walter's response and Mattew's question, that doesn't seem like a good idea. * MMapDirectory JVM sharing This point is the main reason for my message. If several Solr JVMs are running on one server, will MMapDirectory work fine or will the JVMs fight with each other in order to use off heap memory ? According to Shawn's response it should work fine. What would the iops look like? Not monitored yet. Storage configuration is the second point that I would like to investigate in order to better share disk resources. Instead have one single RAID 6 volume, isn't it better to have one distinct not RAID volume per Solr node (if multiple Solr nodes are running on the server) or multiple not RAID volumes use by a single Solr JVM (if only one Solr node is running on the server) ? I note the various suggestions in your answers (ZFS, RAID 10, ...) Thank you Dima and Shawn Regards Dominique Le jeu. 6 oct. 2022 à 09:57, Dominique Bejean <dominique.bej...@eolya.fr> a écrit : > Hi, > > One of our customer have huge servers > > - Bar-metal > - 64 CPU > - 512 Gb RAM > - 6x2Tb disk in RAID 6 (so 2Tb disk space available) > > > I think the best way to optimize resources usage of these servers is to > install several Solr instances. > > I imagine 2 scenarios to be tested according to data volumes, update rate, > request volume, ... > > Do not configure disks in RAID 6 but, leave 6 standard volumes (more space > disk, more I/O available) > Install 3 or 6 solr instances each one using 1 ou 2 disk volumes > > Obviously, replicate shards and verify replicates of a shard are not > located on the same physical server. > > What I am not sure is how MMapDirectory will work with several Solr > instances. Will off heap memory correctly managed and shared between > several Solr instances ? > > Thank you for your advice. > > Dominique > > > > >
