Hello Shawn, Thanks for quick reply. > > Where precisely are you seeing the 98% usage? On the Solr web UI. Although the same Solr UI is reporting heap usage to be below 1 GB. Also I found that Solr Java is holding(VIRT) 8GB of total memory even with Xmx set to 2g using top command.
Can it be due to GC not clearing up the memory ? Sourav Moitra https://souravmoitra.com On Thu, Oct 11, 2018 at 10:24 AM Shawn Heisey <apa...@elyograg.org> wrote: > > On 10/10/2018 10:08 PM, Sourav Moitra wrote: > > We have a Solr server with 8gb of memory. We are using solr in cloud > > mode, solr version is 7.5, Java version is Oracle Java 9 and settings > > for Xmx and Xms value is 2g but we are observing that the RAM getting > > used to 98% when doing indexing. > > > > How can I ensure that SolrCloud doesn't use more than N GB of memory ? > > Where precisely are you seeing the 98% usage? It is completely normal > for a modern operating system to report that almost all the system > memory is in use, at least after the system has been shuffling a lot of > data. All modern operating systems will use memory that has not been > specifically allocated to programs for disk caching purposes, and system > information tools will generally indicate that this memory is in use, > even though it can be instantly claimed by any program that requests it. > > https://en.wikipedia.org/wiki/Page_cache > > If you tell a Java program that it is limited to a 2GB heap, then that > program will never use more than 2GB, plus a little extra for the java > runtime itself. I cannot give you an exact figure for that little bit > extra. But every bit of data on disk that Solr accesses will end up (at > least temporarily) in the operating system's disk cache -- using that > unallocated memory. > > https://wiki.apache.org/solr/SolrPerformanceProblems#RAM > > Thanks, > Shawn >
